Oldfield's Observation Log and Astronomy Topics

Sun related special events in 2012

2012-02-02T17:59:00.002+08:00

1. 日環食

日出: 5:41am
食甚: 6:06am (5-6 degrees above horizon)
復圓: 7:16am (20 degrees above horizon)

Chance is very slim, anyway, worth to have a look, even consider it as a deep partial eclipse.

2.金星凌日

1st contact: 6:12am
2nd contact: 6:30am
3rd contact: 12:31 noon
4th contact: 12:49 noon

Chance is much better given the sun is higher in the sky and the longer duration.

2012-02-01 Short Exposure Imaging

2012-02-01T00:32:00.001+08:00

This is to test the tracking of my Mark-X but since the polar alignment is just rough by using my Android phone to point to north and adjust to the latitude of Hong Kong, so I don't expect much.

I was using my Canon 200mm f2.8L, I've taken a series of shots at 15s each since my home sky was very bright so that I cannot do longer. Stars remain pinpoint and it's a good sign. On extending the exposure to 30s by lowering the ISO reveals some trail, and it's not unexpected and I guess careful polar alignment will fix the problem. Having said that, I don't think I should remove the possibility to adjust the trimming capacitor further.

While I'm still downloading DeepSkyStacker, I pulled one of those JPGs to adjust level and crop the following:

Once the downloading finished, I shall try to stack the raws.

--

Canon 200mm f2.8 wide open, ISO 800, 15s, 14 frames:

20120128 Sun

2012-01-28T21:59:00.001+08:00

We got a clear sky this morning, however, the aperture is partially blocked, so I don't even open the glass window.

So it's just a record of the location of AR1408 and AR1410.

GOTO Mark-X finalized

2012-01-20T12:12:00.001+08:00

Both sides have slow motion control now, the azimuth side was augmented with a dovetail saddle which I already had.This is the front view, one of the sides was mounted using a simple L-bracket, it's thin but it should be strong enough to hold lighter scope and camera. I've drilled an extra-hole to hold a ball head in case I wanted to.

This view shows the difference between two mounting methods. A solid 6061 aluminium block should provide very rigid mounting but yet simple enough.

I made these by using hand drill and hand saw, persistence and patience is the key. It's now much lighter than the setup which I got from the original owner, and it even provides slow motion control which is absent previously.

--

I've tried to test this setup out in the same afternoon by using the sun as the target. Unfortunately, there was so much cloud around, but fortunately, I could truly test the tracking capability of the mount under this situation since when there was a short cloud gap, I could always see the sun!

For Sales: Field Power Supply

2012-01-20T11:32:00.001+08:00

This is definitely a good bargain for those who want a field power solution. I only ask for $100 HKD for all three items since I've no more use of them. I current mount wants 9V rather than 12V and I don't use a notebook in the field now.

First of all, it's a Panasonic 12V 7Ah Sealed Lead Acid (SLA) battery. SLA battery holds charges really well, and you should keep it charged at all time and it's ready for field use any time! There's no memory effect for this type of battery.

And next is the charger. This one will charge a 12V SLA battery and also a 6V SLA battery. Charging is pretty fast and safe.

Finally there's a transformer for notebook, it supports various type of plug and it support 15V, 16V, 18V, 19V, 20V, 22V and even 24V! So you may use it for any other devices as well.

$100 HKD takes them all, just leave me a message.

2012-01-16 Venus

2012-01-20T11:23:00.001+08:00

Ranger at 5x, Lumenera Lu070M, Mark-X.

Nothing special, plan and simple. This mount is pretty strong so that it really attracts me to buy a bigger scope for it!

Sawing the mounting block of Mark-X

2012-01-20T09:48:00.001+08:00

The mounting bars were not cut to exact size. Now, I would like to fix this problem with a borrowed hand saw... it's a hard job indeed, but all I need is patience.

The left side was already finished, the right side is being sawed... it takes a lot of effort, 100 "slides" translate to around 1.5mm at best! 6061 is just strong.

Cutting off the excessive mounting block makes the whole thing looked a little bit better, and it's also more "portable" in the sense that less strange parts here and there.

Cabinet clearing sales

2012-01-11T22:25:00.000+08:00

Package deal: $999 HKD takes them all!

Individual items price reduced, all reasonable offer will be entertained, just don't want to waste all these stuff.

Generic Chinese ball head, good quality, rated at 4kg. Ask for $200 HKD.

Shoestring FCUSB, virtually new never used in the field, ask for $400 HKD. Control and power your JMI focuser via your USB port.

Sealed Lead Action battery, reliable power solution in the field. Comes with a Panasonic 12V 7.5Ah SLA battery, a charger which will take 12V or 6V SLA, and also a generic notebook transformer which offers 15-24V by using the 12V SLA. Ask for $100 HKD for all three!

And next is the charger. This one will charge a 12V SLA battery and also a 6V SLA battery. Charging is pretty fast and safe.

Finally there's a transformer for notebook, it supports various type of plug and it support 15V, 16V, 18V, 19V, 20V, 22V and even 24V! So you may use it for any other devices as well.

Next is a 70mm doublet (f=500mm) mounted and with 77mm thread, suitable for macro imaging which brings the closest focusing distance down to less than 500mm. Ask for $150 HKD.

Celestron Nexstar mount parts, the gears were still available at $100 HKD as shown below, the bigger one was about 6" in diameter and the smaller one was 5".

JMI 2" -> 1.25" compression ring adapter, $100 HKD:-

Never used JJC EC-2 Eyepiece Extender for Canon EOS DSLR, $30 HKD:-

Another custom machined 2" to 1.25" adapter, it's pretty heavy and could be good for balancing light weight 1.25" eyepiece and heavier 2" eyepiece. With two locking screws for added security. Ask for $50 HKD.

Originally for my Gitzo G1415 when I lost one of the spikes on the legs, so I still have two remain. I've sold my G1415 and now they're sitting idle... very hard to find in Hong Kong and even the distributor refused to order them for me. Ask for $200 HKD.

A small 7-14x monocular, good quality for this size, ask for $50 HKD.

GOTO Mark-X mounting plate with counter weight, ask for $100. The gray mounting plate was sold and is not included.

First light of Mark-X with slow motion control

2012-01-09T23:02:00.000+08:00

The attachment is pretty successful, and slow motion control is a joy to use. Now high power imaging is just easy!

So these are two images taken with this setup. The one on the left was taken at 30fps and the right one was taken at 15 fps.

Far more detail could be seen given this mature setup. I'm encouraged with this little but solid mount!

GOTO Mark-X 補完計劃

2012-01-07T12:34:00.001+08:00

機緣巧合之下，覓得經典攝星儀 GOTO Mark-X，很快就被它的工藝所吸引，決定要為它配一個摩打，並把原本機主的重型 mounting system 改成更輕便的系統。

小弟既不熟電工，也不懂金工，但這也是樂趣之所在，學習與娛樂集於一身。

首先是摩打部份，主要是電工與金工的配合，先來電工部份：

Hacking based on Tele Vue (Carton) CXD-1 motor

然後是金工部份：

Mounting the motor

之後是把一個 slow motion control 接上，這涉及搭載望遠鏡，所以必需穩固，也要有微調：

Mounting the slow motion control

萬事俱備，只欠天氣。

2011-12-31 Sun and Moon

2012-01-05T20:38:00.000+08:00

These were two independent observations. First up was the sun:

It was taken with a reducer.

Next up was the moon, the first one was a mosaic of two frames, actually, the 1/3" CCD was just a little bit smaller than the image.

And in order to try out the tracking performance of my Mark-X, I inserted my 5x Powermate and it works out fine:

So, the Mark-X really creates a lot of opportunity for different observation, the high loading plus the excellent portability left nothing to be desired.

Integration hardware

2011-12-31T11:32:00.000+08:00

Now, I've two worm driven slow motion controls as detached from a new Porta-like mount, and I also have a ball head, but I will need some ways to put it on the Mark-X.

In order to do that, I've ordered two 6061 aluminium bar of 2cm * 2cm, with that kind of thickness, it should be able to provide shake free attachment. These solid bars were not cheap at all, but then it's still only 30-40% of the price quoted by a local machinist.

All I will need to do is to drill two holes to mount them to the Mark-X, and drill two more holes to put on the slow motion controls, and maybe one more hole to put on the ball head.

Actually, I've an 9mm thick solid alumnium bar at home which could be used. But after drilling the holes, its wall thickness near the hole became less than 1mm (with a 1/4" hole) which is just too dangerous and will break suddenly without any warning. So a 20mm thick bar should leave some more safety margin.

--
Updated on 2012-1-3:-

Due to the new year holidays, the package arrived today finally.

On fixing to the Mark-X, my existing M5 screws should be long enough since the existing mounting hardware is exactly 2cm thick.

On fixing to the slow motion controls, I will need four M6 screws which is slightly longer than 2cm, and 2.5cm should be about right.

--
Updated on 2012-1-7:-

6061 2cm by 2cm aluminium block is harder to drill than I imagine.... anyway, persistence is king.

For the first block, I didn't lock the metal block firm enough and it was released suddenly and it hurts my hand lightly.

So for the second block, I used a clamp to fix it in place, and in order to attract all those metal debris in place, I have placed the metal block in a cup of water before drilling, and keep adding droplets of water to reduce the temperature increase during the drilling process:

Drilling holes through thick metal block using a hand drill is difficult and it's hard to be very accurate.

The attachment was firm and secure, but the metal block was a little bit too thick such that the polar scope cover could be fully screwed into place afterward.

Later I found that I just don't need the dovetail saddle, and all I will need to do is to mount my Ranger directly to the M8 mounting holes on the slow motion control. I've drilled a hole on my Ranger mounting ring in order to do that.

On the other side of the Mark-X, I left opportunity to mount a camera ball head or another slow motion control.

Altazimuth mount arrived

2011-12-29T00:38:00.005+08:00

It arrives in great condition. It works quite good and it's built quality is pretty good as well.

The worm shaft was 6mm and I've some brass gears and metal shaft couplers on hand, motorizing it should be rather easy by mounting my existing DC geared motor to it.

Removing those slow motion controls were easy as well, you can always assemble it together again if you want. It could be attached to the Mark-X rather easily by using a simple L-shape plate.

A fully operable dual-axis EQ mount should be ready very soon!

The bottom half of the mount could be used very easily as a portable EQ mount!

I've further removed that 3/8" adapter on the bottom half and so I got two identical worm driven slow motion control as shown below:

On the bottom side, there are three mounting screws but there are six threaded hole for mounting in total. On the top side we had 8 M8 threads holes, these holes come in four opposite pairs separated by 35mm which is Takahashi compatible.

On the upper unit, a Vixen compatible dovetail was included and fixed by four M8 screws. The lower unit was fixed to the mounting arm with two M8 screws. There units were filled with typical Chinese glue like grease but they worked quite well actually.

Portable EQ tracking mount idea

2011-12-26T18:04:00.000+08:00

There are several portable EQ tracking platforms available from the market, like TP-1 from a local dealer, a CD-1 from somewhere else. Now, I'm wondering if it could be made rather easily with off-the-shelf components.

First of all, the mechanical part could be acquired by disassembling those Vixen Porta-like mount (120 tooth), by doing that, you can effectively make two such EQ tracking mounts.

Secondly, the motor could be hacked by other existing RA tracking motors. For example, the Carton CXD-1 controller which I bought. One can always change the crystal to adapt to the different teeth numbers.

With that in mind, you will be able to have two such mounts by disassembling two Porta-like mount ! Even if we factor in the cost for those Aluminium plates and screws, we can easily keep the cost rather low.

I shall explore such opportunity once the Vixen Porta-like mount arrived. I've at least one of the two axes as spare part. I guess I can keep this kit at around $1000 HKD.

2011-12-24 Jupiter

2011-12-24T22:46:00.000+08:00

Home alone in the Christmas Eve, I pulled out my Canon 100-400mm f5.6L for some fun. Mounting it on my Mark-X, it's an easy loading indeed.

I'm trying to use my Canon 450D for planet imaging with EOS Camera Movie Record by using its LiveView mode. I'm using the latest version which supports 5x as ROI so that you can move around the chip! That's really great for centering the planet since we have a really huge APS-C chip especially when compared to a 1/4" ToUCam Pro CCD or a 1/3" Lumenera LU070M CCD!

The "motorized focuser" of the Canon 100-400mm is a joy to use, you can even remote control it via USB with software. It's just silent and accurate with the USM, a fantastic experience.

I've tried to use it at 400mm f/5.6 but it's too short for fun, so I jumped up with a Kenko 2x and thus it becomes 800mm f/11.

With the extremely poor seeing tonight, the two major cloud belts were well resolved. So there's a good potential actually. I'm using ISO 400 at f/11, 1/60s. Notice that a regular telescope can do f/25 easily and thus, I believe I will need another 2x to fully unleash its power.

Ordered an altazimuth mount!

2011-12-24T20:49:00.000+08:00

Why I am doing this?

First of all, by selling my TG-SP II, I got back some cash together with this Mark-X, but even if I inject 1/3 of the original cost of my TG-SP II, I would be able to get back a fully operable mount, so it's a real bargain, indeed.

I've a plan to remove the slow motion control of this altazimuth mount and re-fit it to the Mark-X as the DEC axis. This will facilitate high power imaging. In addition to that, from what I've seen, this part should be motorized rather easily, so I will have a dual axis mount for higher power imaging.

For the other axis, maybe it could be used to aid polar alignment? I don't know...

That's the first time I bought stuff from www.taobao.com, see how it works out. The pricing is definitely attractive.

2011-12-23 Jupiter

2011-12-23T23:33:00.001+08:00

Temperature keeps dropping along in this windy night. Seeing like 0.5/10, too bad that I don't want to rate it. Jupiter appears as a featureless disc except during some very brief moments with that two major cloud belts. You can't even know you're in proper focus.

Armed with my motorized Mark-X, tracking is a joy even with rough polar alignment. This motor delivers a lot of torque even I've nothing on the other side for balance, it tracks very well! Here's a shot with the existing mounting adapter which is heavier than the mount body!

So you see the scope was actually quite far away from the RA axis, so the torque could be huge even with a small scope, but the motor works very well.

Due to the poor seeing, I just did an over-exposure to bring out the Jovian satellites at prime focus (i.e. 480mm):-

With this initial success, I pushed the power to 960mm and then capture thousands of frames with my LU070M, and after stacking, the cloud belts were clear and good:-

Knowing the poor seeing, I pumped with the image scale with 2400mm but then nothing could be seen as expected, I just want to try out the tracking. I've to adjust the DEC axis manually in order to re-center my target after several minutes of tracking, but this is a result of poor polar alignment rather than the tracking motor. It seems like if I want to do high power imaging, I would need a motorized DEC as well... it should cost me something like another $600 HKD, got to think about that. But I won't do it at this moment.

I'm getting some fun out of my good old setup. The adventure with the Mark-X brings a lot of joy without any high cost. It's why amatuer astronomy was so much fun.

2011-12-23 Sun

2011-12-23T13:08:00.000+08:00

Closed window shot, tripod was not used, just the Ranger leaning on a metal block, and a simple ballhead, I even had to fix the setup in place and asked Alby (my elder 9 years old daughter) to click the record button for me.

The darkest patch on the lower left is AR1384.

It seems like the local friend-like dealer does not have density 3.8 Baader filter, so I will need to search for it on the internet. On the other hand, I've another idea to built the mounting adapter of my Mark-X, it might carry four instruments at once but it's not the main point, the whole idea is to make it more stable but the capacity to carry more instruments is just a side effect.

2011-12-19 Sun

2011-12-19T15:14:00.003+08:00

It's time to test my Mark-X after the integration with the Carton CXD-1 motor (Tele Vue System Mount OEM).

I'd say it works perfectly, I've zero complain. Despite my existing mounting plate does not allow balancing, the motor proved to deliver enough torque to turn the mount very nicely in both directions, and even at FAST mode, it works great without any major backlash.

First one is taken with my DIY blue filter with reducer lens, so I can take the solar disc in a single shot:-

Second one is taken with a 2x barlows plus a green filter, close up of AR1381 and AR1382:-

Only the original Ranger focuser was used, the mount is a bit shaky during focusing so the focus is not very accurate.

--

I left the motor running for several hours after taking these images, and it tracks nicely.

Longing to test it under the star, maybe I shall try it out tonight from inside home if possible.

GOTO Mark-X: Improved motor mounting

2011-12-19T12:54:00.000+08:00

The initial mounting method has been quite ugly and ad hoc, so I took the plunge to go back to my original design. That is, to drill a hole on the original motor cover in order to fit a long bolt to connect to the mounting hole of the Mark-X.The drilling hole couldn't be too accurate since I don't have the proper tools and skills. Therefore, I started off with a very narrow drill bit so that I could refine the position after the initial drilling. After the initial drilling, I found that I am pretty on-spot and it should be accurate enough after fitting it to the mount. A good sign, but a drill bit was killed during the process which was expected.That I changed for a thicker drill bit to do the final drilling. It turns out to be accurate enough especially I was using a flexible shaft coupler which allows a little bit more tolerance.This is the final product:

Pretty elegant, right? In order to fix the motor in the field, all I will need is a small hex key to engage the shaft coupler and then I will need to fix a small nut at the other end.

Actually, the bolt head was a little bit too thick to hide completely inside the motor cover, but then it's just a little bit over. You can see from the photograph below that the motor cover was not completely hide below the black compartment, but it's fine enough.

So far it's one of my best DIY projects. I'll do a beta testing soon by using the sun as my target.

Next Step: A Better Mounting Plate

Lighter in weight
Allow balancing
Cheap and simple

--

Update 2011-12-19:

I've inserted a nylon locknut on the other side of the mounting hole on the Mark-X, it further fixed the motor in place.

For the mounting plate, I tend to keep it simple and stupid in order to keep the cost low. Currently, I'm thinking that I might give up the facility for balancing by sliding since it is much simpler to make, and it's far more compact for transportation.

In order to alleviate the problem, I will keep the mounting plate very short so that the torque due to imbalance would be reduced. Secondly, I can always hang the battery pack or attach something else on the lighter side to enhance the overall balance.

I've some ideas in my mind by using short angle aluminium plate and I've some scratch materials at home so that I could do some testings without cost. The only problem is whether the vibration damping would be good enough or not, and also the varying degree of flexure during tracking.

I believe this idea would work, the problem is the choice on material.

I guess thicker angle aluminium plate would work, the problem is where to buy them. If that was not strong enough, I think thicker aluminium bar will do the job, the problem again is sourcing.

GOTO Mark-X Alpha Testing

2011-12-17T12:28:00.000+08:00

I have been longing for this. With the shaft couplers and the screws on hand, I proceeded to do the integration this morning. First of all, I found that stainless steel plate which I've bought yesterday was too strong, the electric drill was not doing well on making holes on it, or even just to enlarge the holes. I guess it could with some more persistence but it might kill several drill bits before it could be done.

I have used a very soft aluminium plate which I already had to do the job, and it worked out fine. In short, here's a short video to show it at work!

Originally, I have mounted the motor on one side but then I found that the 410 head would block its way and thus, I have to move it to the other side of the mount.

Fully assembled and ready for testing. So, I have attached the heavy DIY mounting plate of the original owner to it, mount my Ranger on one side and the do some ugly solar imaging.

It's really nice to have a motor, you can use it to fine tune the position of the target and you can have the target stay in place without moving the setup a bit. Vibration of this stepper motor is minimal. Since I was only testing the motor, I didn't even open the window to shoot the sun, so the image was ugly but then it serves the purpose of testing the motor. I don't even bother to process it carefully.

So far so good!

Here is a list of pending tasks:

To find a good and quick way to remove and re-attach the motor in the field. I expect my mounting screw and plates will break very soon if I kept them in place during transportation.
Fine tune the trimming capacitor with good polar alignment.
Further improve the mounting
Make a better mounting plate, the existing one was too heavy and it lacks the ability to allow proper balance.
Anything else?

The Crystal Arrived - the quest for Mark-X motor

2011-12-14T20:14:00.001+08:00

The stamp reveals that it comes from Thailand, it's well packed and in great shape.

With some careful observations, I've cut off the old crystal which is longer and bigger in size. I've carefully bended the legs of the new crystal and try to fix it in place with a tape. Then I proceed to solder it in place. It's not an easy job since the legs were in a rather crowded place. I tried to melt a tiny ball of solder and then dip the whole ball into the joints.

After the soldering work, I switched on the power to check the time required for a complete rotation, it should be longer than 8 minutes (180 teeth with the original crystal) and it's hopefully 11 minutes and 25.7 seconds (126 teeth with the new crystal), but I know the speed will be slightly different since the crystal is not really 3.68MHz but 3.6864MHz.

With my best effort timing, the time required for a full rotation is now 11:10s.

After adjusting the trimming capacitor for two clockwise turns, the time for a full rotation is then 11:22s.

And the third adjustment yields 11:26s... and I won't adjust it further, since my timing method should not be accurate enough to be meaningful.

Still need to wait for the shaft coupler, and then I shall attached this motor to the mount for a real test under the stars!

Before:-

Original crystal carefully removed:-

New crystal placed in location:-

Ugly soldering job done:-

Updated 2011-12-16 (afternoon):-

The source of this motor is pretty good, the seller said he has more than 50 pcs in stock. Thus, I won't bother to buy backup at the time being.

When I go out to work this afternoon, I found that shaft coupler was already in my mailbox, it's very nicely machined with light weight but thick aluminium.

On the way to office, I have bought several M6 screws, nuts, and a small stainless steel mounting plate. And I guess I shall be able to fix them together. Hopefully I won't need to drill any holes except to enlarge a few holes by tapping.

Updated 2011-12-16 (night):-

The shaft coupler gives a perfect fit.

The M6 screw for the mounting hole on the Mark-X fits very well, too.

The M6 screw for the motor fits excellent as well.

But that small mounting plate needs bigger hole to accommodate the M6 screws but then it's harder than I imagined, so I will need to enlarge the holes tomorrow with a drill. Can't do it tonight since I've no drill on hand.

Another Mark-X mounting plate

2011-12-12T18:19:00.000+08:00

Sliding mounting is not strong enough and it is actually not really needed, for balancing, all we need is a single sliding mounting slot.

The L part is for mounting a rotatable quick release plate for my Ranger. It should be made as close as the polar axis so that it could be balanced easily.

Cabinet clearing sales update

2011-12-12T16:23:00.001+08:00

Package deal: $999 HKD takes them all!

Or name your price, reasonable offer will be entertained, just don't want to waste all these stuff.

Astrotech 1.25" dielectric diagonal in great condition, flawless mirror and with the original box, ask for $350 HKD (SOLD).

Shoestring FCUSB, virtually new never used in the field, ask for $500 HKD. Control and power your JMI focuser via your USB port. Ask for $500 HKD.

Next is a 70mm doublet (f=500mm) mounted and with 77mm thread, suitable for macro imaging which brings the closest focusing distance down to less than 500mm. Ask for $200 HKD.

Celestron Nexstar mount parts, the gears were still available at $100 HKD as shown below, the bigger one was about 6" in diameter and the smaller one was 5".

JMI 2" -> 1.25" compression ring adapter, $100 HKD:-

DIY 43mm male thread afocal imaging adapter, $20 HKD (SOLD):-

Never used JJC EC-2 Eyepiece Extender for Canon EOS DSLR, $30 HKD:-

A small 7-14x monocular, good quality for this size, ask for $50 HKD.

GOTO Mark-X mounting plate with counter weight, ask for $200. The gray mounting plate was sold and is not included.

Brass counter weight, 3kg with 20mm bore, ask for $100 (SOLD).

20111212 Sun

2011-12-12T15:04:00.001+08:00

Yes, I'm going solar imaging again with my pinholes filter. I do it because I would like to try out my latest configuration of my Mark-X. A simple rotatable quick release plate is now used as the DEC body. Given a carefully balanced setup, it's operable even at 960mm with ease. I'll settle myself with that at the time being for another ballhead does not help for minor adjustment, careful balance is even better!

This short imaging session is also to test my newly DIY reducer lens, and the results can be shown as below:

This is a mosaic of two frames. I believe that I can adjust the position of the reducer lens in the optical chain to allow one shot full disc like before.

I've fine tuned the polar alignment with a good quality compass and an inclinometer application running on my wife's Android phone. With 2x, hand tracking was easy with minimal vibration and the polar alignment seems of good quality:

The bigger group is AR1374 and the smaller group is AR1375.

After this brief solar imaging session, I began to investigate ways to make a better reducer to get full disc without stitching mosaic. I've attached a small binocular objective to a generic blue filter by using those instant glue and the result seems great! Even the built-in focuser of my Ranger could reach focus. Here's a snapshot of the sun through glass window:

It's not calcium K but just a general blue filter as below:

The lens edge could be blackened to further improve the quality. Now, I only wish to have a Baader 3.8 solar film for my Ranger so that I can do high power at better quality!

20111210 Total Lunar Eclipse

2011-12-11T20:08:00.001+08:00

With the excellent weather forecast, it's a must to go out. Lunar eclipse does not require a dark sky but a darker sky will pay off since you can capture the (much dimmer) moon in front of the starry sky which is impossible except during lunar eclipse. But life always means trade off, you have convenience and family, and better skies, and I chose the former option.

As planned, I went to a nearby playground to setup my gears. It's around 10 minutes walk from my home and the view is proven since the last partial solar eclipse. I went there first after having dinner with my family at around 8:20pm.

Then my wife and my kids arrived at around 9:00pm and then a couple of friends came a bit later.

Some snapshots taken during totality:

And finally an eclipse sequence, please click to enlarge:

Total Lunar Eclipse Observation Site

2011-12-09T10:15:00.001+08:00

Last night I went out jogging as usual but it was a planned one. Jogging aside but checking out the site on spot was the real purpose. You know the moon travels along the sky and the exact path is not difficult to predict but then it's not always easy to predict whether it will be blocked or not especially with all those trees and buildings in sight. To put it short, I've found a perfect spot near my home. And I've been there before for the partial solar eclipse around two years ago:

http://osastrolog.blogspot.com/2009/07/2009-07-22-partial-solar-eclipse-in.html

This map shows how to get there, nearby landmarks were Nam Cheong station (西鐵南昌站), Metro Harbor View (港灣豪庭), etc.

And the exact spot where I will be observing. Inside the playground, you will see a path where you could go up, and I will be up there since it will clear up all the trees.

For the eclipse detail, see here:

http://www.hkas.org.hk/eclipse2011/

And as from the timing chart, you will see that we won't detect major changes until 20:45, so I guess that I won't be there until 20:20 and totality will be around 22:31, and I won't stay late unless the sky is suboptimal such that I'll need to catch every chance.

I will take my tripod on a manual tracking mount, a small telescope (my only one now), a pair of binoculars and of course, my camera. You will see an interesting eclipsed moon at first and then a deep red moon hanging up there if sky allows during totality.

If we miss that opportunity, we will need to wait until 2015! This year we have two of them but the last one was not well observed due to the poor weather.

You are welcome to join me, but please call me to confirm whether I'm there or not. I might go somewhere else to get good composition with some interesting terrestrial targets.

Updated 2011/12/10:

The weather was getting nice and we have a blue sky now! I will finalize my equipment line up like this:

1. Gitzo G106 with Manfrotto 410 head (skip the Mark-X)
2. A long mounting plate for both my Ranger and my camera
3. A simple DC of my daughter
4. Canon 10x30 IS

I've removed the JMI NGF-CM from my Ranger and use the original focuser to ease my load, 2" wide field is not required for lunar eclipse.

Modifying the motor and controller for Mark-X

2011-12-07T17:36:00.001+08:00

I have found source of very cheap 3.68MHz crystal and so I asked myself, why not give it a trial?

By using a pair of gears, the complexity of the system increases and the cost also increases. So before I go that route, I should try to do it myself.

Order has been placed for the crystal, and tonight I shall also order the shaft coupler. Or shall I wait to see if the speed was successfully change roughly or not first? Of course, the shaft coupler is not that expensive after all, and thus, I guess I will proceed to order the coupler as well.

Mounting the motor should not be impossible for me as a DIY project. I should be able to keep the cost of these hacking well below $100 HKD which is way cheaper and simpler than using a pair of gears.

==

Updated on 2011/12/7

- Crystal ordered at $0.99 USD

- Shaft coupler ordered at $4.99 USD

Updated on 2011/12/8

- Both items were marked as shipped, I'm feeling excited!

- In order to attached the motor to the mount, I guess all I will need is to buy a long bolt and some matching nuts, and to drill a hole on the motor mounting plate. It should be well manageable to me as long as the crystal hack works as expected.

- After reading the document here:

http://www.foxonline.com/techfaqs_cry.htm#a25

I found that HC49U and HC49US differs by the pullability only, and thus my hack is going to be okay in that case.

- A local astronomer confirms that:

[QUOTE]

Dear Oldfield,

HC49U is standard size (~13 mm high).  HC49US is low-profile size (~ 5 mm high).

Since your clock circuit is using non-high frequency crystal (5.257 original  vs 3.68 MHz presumeably), I think HC49U and HC49US makes little difference in trimming capacitor.
Just try it.

Alan

[/QUOTE] 

Another step closer!

Updated on 2011/12/9

Simple calculation yield that the unmodified motor should do one rotation in 8 minutes (1440/180), and I'm trying to do a rough measurement by using a stop watch. The simple measurement confirms that it's indeed a 180 teeth motor.

The above measurement was conducted by providing the rated 9V DC to the controller. By reducing the voltage to 6V, the speed is the same. The hand controller has a rated voltage range of 4.5V to 12V, and at 9V, it consumes 160mA. I was doing that because 6V is simpler to get by using 5 AA rechargeables rather than 8 of them.

By using the simple formula of Power = Voltage * Current, if I use 5 AA rechargeables at 6V, the current consumption will then be 240mA. Suppose I'm using 2000mA eneloop, a set of 5 will provide enough juice for 8 hours which translate to a whole night of tracking!

After replacing the crystal, it should do one rotation in 11.4 minutes (1440/126) if it's done correctly. Since it will be running at a slower speed, the energy consumption should be slightly lower as well. Sounds like a good setup for wide field astrophotography.

On mounting, I will need a single long bolt of 9-10cm, and that mounting hole has a diameter of around 6-7mm (like 1/4 inch?), so a M6 or 1/4" bolt of 9-10cm would do the job. I will need 3 matching nuts at least. The bolt should hide under the motor cover, and fixed on the other side of the cover with a nut, and then fixed to the mount with two nuts, one of either side of the mounting hole on the mount.

Found that the motor cover was pretty thick, and maybe thick enough to tap thread there...? and there should be at least 2mm to sneak hide the bolt head inside, good!

Updated on 2011/12/10:

This morning, I searched round my scratch box to see if there's anything useful. I found a 4 AA battery box with an on-off switch. The hand controller of my motor does not have any on/off switch and it should be nice to have one on the power supply. 4 AA rechargeables yield 4.8V which is near the lower limit of the input voltage. The motor did turn but the LED on the controller keeps blinking and it should be an indicator of low battery. On timing the speed of the motor, I found that it was slowed down to more than 7 minutes for a half rotation and that's too slow even without changing the crystal. Worst yet, the motor might turn even slower when the power level drops. Therefore, I don't think it's viable.

I think that I should find a battery box with 6 AA and an on/off switch, it will draw 200mA at 7.2V and a set of fully charged eneloop should be very safe for a whole night of operation.

Updated on 2011/12/12:

I've conducted experiment to tune the trimming capacitor of the crystal and I found it quite an ineffective way to change the speed of the motor. On making two complete turns, the speed only differs by 8s. Therefore, it's a way to really fine tune the clock speed.

20111206 Jupiter and the Moon

2011-12-06T23:52:00.001+08:00

Jupiter and the moon were quite close to each others tonight, it was cloudy at first but then sky cleared eventually to allow me to take a few snapshots.Images taken with my Canon 200mm f2.8L prime lens. The internal reflection is quite serious, and in the following image, the moon like object is indeed a ghost image and the bright patch on the right is the real moon.

By removing the Kenko filter, the ghost was dimmer but it was still there. It explains why my total solar eclipse images were all "haunted".But adjusting the exposure for the moon, Jupiter was rendered as a dim dot.

All images taken on a fixed tripod without tracking.

Fine tuning the Mark-X

2011-12-05T14:39:00.001+08:00

I found that by using a rotatable quick release mounting plate in a carefully balanced position will allow mounting my Ranger on it with fine adjustment like panning at higher power. When coupled with the manual slow motion control of the Mark-X, that rotatable mounting plate will serve as a cheapy DEC body. Probably enough for shooting the upcoming Lunar eclipse.

On the other side of the mounting plate, I'll have a ball head where it could be used to align with my Ranger on the other side. The ball head could also be used to adjust proper balance.

The 410 head was carefully locked to my Gitzo G106, and the shake is reduced to minimum. After using this setup for the coming Saturday, I shall then proceed to the local machinist to attach the motor for tracking.

If everything went fine, I may want to order an extra set of motor since I found the original seller has one more set at least for backup. And I shall further see if I should keep my 5x Powermate or not for some high power lunar shot, or even game like planet imaging like what I did like ten years ago.

I shall go jogging on this Thursday night in order to see whether a nearby playground could be nice for observation.

Nexstar Mount Gear Set

2011-12-05T12:26:00.001+08:00

More information is provided here for ATM:

The bigger one was about 6" in diameter and the smaller one was 5", the central hole was 22mm in diameter:-

In addition to these two gears, there's an additional mounting block which holds either of the two gears in place (22mm shaft).

This is the other side of the mounting block where you could put a telescope, or dovetail saddle or whatever you will want to mount on it.

This mounting block could be attached to either of these two gears with a roller bearing and plastic "washer" as some sort of "slip clutch":-

Given this combination, you may want to use them as a DEC body or even a RA body with a suitable motor.

Ask for $40 USD shipped for the above. And I can include two DC geared motor with matching brass gears at $40 USD extra, they could be used to drive the big gears.

Spectro-heliography

2011-12-05T00:17:00.001+08:00

Just to keep a record of related links for further research and investigations:

http://www.astrosurf.com/joseribeiro/Eespectroheliografia.htm
http://www.astrosurf.com/spectrohelio/index-gb.htm
http://www.astrosurf.com/buil/lhires2_sun/first.htm
http://en.wikipedia.org/wiki/Spectroheliograph

I'm wondering if these could be do-able for me as an alternative way to get back into solar astronomy.

20111203 Moon

2011-12-03T23:09:00.001+08:00

Clear sky and boring heart, pulled out my Ranger and Lu070M for a short shooting session. Without a tracking mount, I must do hand tracking. Centering the moon with a ballhead is like a joke, but it's not impossible if you can give up a little bit precision. Tracking is virtually useless due to the shake introduced by the slow motion control cable.

This time, I limit myself for using prime focus and then going for 2x. I left my 5x Powermate since I don't want to trick myself any more.

Let's see the first two at prime focus, fine detail could be resolved without any problem.

The fast frame rate of the Lu070M certainly helps to generate over 1000 frames while the image of the moon drifts...

With 2x barlows, this one has less than perfect focus:-

Again with 2x barlows, focus fine tuned:-

Just for fun... seems like even if I have a motor for the Mark-X, target centering at high power is still very hard. Got to think of a good solution.

Updated: Various Accessories for Sales

2011-11-23T12:03:00.001+08:00

Package deal: $999 HKD takes them all!

One more item added (2011-11-25)

Or name your price, reasonable offer will be entertained, just don't want to waste all these stuff.

Astrotech 1.25" dielectric diagonal in great condition, flawless mirror and with the original box, ask for $350 HKD.

Shoestring FCUSB, virtually new never used in the field, ask for $500 HKD. Control and power your JMI focuser via your USB port. Ask for $500 HKD.

A pair of felt lined 5.5 in (ID) tube ring with mounting plate. (SOLD)

Next is a 70mm doublet (f=500mm) mounted and with 77mm thread, suitable for macro imaging which brings the closest focusing distance down to less than 500mm. Ask for $200 HKD.

Celestron Nexstar mount parts, the gears were still available at $100 HKD as shown below, the bigger one was about 6" in diameter and the smaller one was 5".

JMI 2" -> 1.25" compression ring adapter, $100 HKD:-

DIY 43mm male thread afocal imaging adapter, $20 HKD:-

Never used JJC EC-2 Eyepiece Extender for Canon EOS DSLR, $30 HKD:-

A small 7-14x monocular, good quality for this size, ask for $50 HKD.

GOTO Mark-X mounting plate with counter weight, ask for $200. The gray mounting plate was sold and is not included.

My Astronomy Corner

2011-11-23T10:51:00.001+08:00

This morning, while I'm looking at the window which is my astronomy corner, and it's now full of other stuff and plants, then I proceed to write the following.

Earliest stage: I was using my Tele Vue Ranger on my Gitzo G106 with Manfrotto 410 head. I scanned around from the limited window. I lived in the city center but it was an old factory area and thus, it's pretty dark at night. In the days of good transparency, I could identify quite a number of constellations there. In addition to my Ranger, I would also use my Pentax 10x50 PCF III.

Planet stage: I was using virtually the same setup. I acquired a Philips ToUCam and begin the work of hand tracking with a 5x Powermate! Guess what, it's doable and I could resolve a number of cloud belts on the Jupiter, and I could resolve the Cassini division of Saturn as well!

Encouraged with these results, I was tempted to go tracked planet imaging. I've conducted a series of feasibility test to see what's the biggest aperture that I could use. I've tried a Nexstar 5, and I finally settled with a C8. The C8 is a very big scope when used with an open window, but then I found a Giro mount with Tech2000 GiroDrive could do the work! I considered it a huge success since I managed to capture the great opposition of Mars, and some nice moments like the double shadow transit of those Galileo satellite of the Jupiter.

But then my kid grew up and they would like to buy a piano, so I've to reduce in size since my astronomy corner has to shrink in size, there's simply insufficient room for me to keep those bigger gears. In the hope to get better image, I sold my alt-az tracking Giro mount and replaced it with an equatorial mount (LXD55). I have replaced my C8 with a C5.

With new imagers like DMK 31AF03, DMK 21AU04, DBK 21AF04... I could approach or even exceed the images taken with my C5 than my C8!

Solar stage: Guess what, I was addicted to solar imaging and in particular H-alpha. And I also got a fantastic deal on a second hand Solarmax 40. On the other hand, I found that with my C5, I couldn't do much no matter how I squeeze but I found H-alpha imaging more or less undeveloped by then.

At first, I couldn't understand why my ToUCam H-alpha images were so bad! But one day, a thin layer of cloud moved into the field of view and I then know there must be something wrong with the color camera. I found that with my color camera, there're two correct exposures! Then, I began to study the inside of the CCD and I found the Bayer color filter matrix was the problem! Only 1/4 of the pixels were useful in H-alpha and thus, I ordered the b/w chip to replace for my ToUCam Pro! Guess what, I've stucked myself with at least four or five ToUCam Pro in total, but they all suffered from premature death. Blame me on my poor soldering skill?

I've found that monochromatic imaging would be the key. Thus, I took the plunge. I was among the very first people who ordered a DMK 31AF03 from a Australian non-astronomy dealer. It gave me huge success over b/w modified ToUCam Pro due to its much better circuitry and uncompressed high frame rate.

With this success, I proceed to do imaging of the sun in Calcium K, and then I also did white light with a Herschel Wedge. Those were really lovely memory.

Minimizing stage: I've a very clear calling from above, so I quit my job and go for the seminary. And after my graduation, my wife also got the same call and thus, In order to survive and to make myself "lighter" for any new challenges, I began to sell most of my astronomy stuff. Right now, I only have my aged Tele Vue Ranger which no body would buy it since the lens was not in good condition. I've sold all my solar filters except an aged Thousand Oaks Type 2+ which was filled with "millions" of pinholes. I've even sold my TG-SP II which I planned to use for wide field imaging for life time.

Now, I may still do what I used to do in the early beginning and in fact, I still have more than I had in the earliest stage. I am sure that I shall continue with this wonderful hobby.

GOTO Mark-X Motor Candidates

2011-11-19T13:03:00.001+08:00

The Tele Vue System mount motor arrived yesterday, it's a new one from stock. I found the mounting of this motor to the Mark-X non-trivial and I probably need a machinist to help me out. At the same time, I will need to hack the crystal to accommodate the speed difference:

And meanwhile, a Cloudynights buddy reported that another simpler drive could also accommodate 126T without modification, and the mounting could be easier as well.

In that case, the calibration of speed might be the hardest part, I will need accurate polar alignment and then I can adjust the speed, maybe with the help of my Lu070M. However, it could be hard to have very accurate alignment without a properly tracking motor? An egg and chicken problem.

So, I'll need to see which way I should go.

Various Accessories for Sales

2011-11-10T23:01:00.001+08:00

Package deal: $999 HKD takes them all!

More items added but price reduced. (18 Nov 2011 update AGAIN) (21 Nov 2011 three more items and the same price)

Or name your price, reasonable offer will be entertained, just don't want to waste all these stuff.

First up is a 70mm doublet (f=500mm) mounted and with 77mm thread, suitable for macro imaging which brings the closest focusing distance down to less than 500mm. Ask for $200 HKD.

Astrotech 1.25" dielectric diagonal in great condition, flawless mirror and with the original box, ask for $350 HKD.

Generic small Chinese ballhead, suitable for digital camera, ask for $50 HKD. (RESERVED for CL Chan)

Shoestring FCUSB, virtually new never used in the field, ask for $500 HKD. Control and power your JMI focuser via your USB port. Ask for $500 HKD.

Celestron Nexstar mount parts, including both motors with encoders, also the gears.

Ask for $400 HKD, the motors alone should cost more than that. And I got the following information from a CN buddy:

"These were used on the original Nexstar 5 and 8. The 5 and 8i used Lo-Cog Pittmans with different encoders. These things are available for about $275 each new.

The same early motor was used on the classic Meade LX200 16", although the gear reduction was 19.5:1. I was able to find a recent series 8000 Lo-Cog on eBay with the correct gear ratio and swap the gear heads to get the 19.5:1 ratio.

The Meade used a different encoder count too, so the HEDS encoder and the code wheel have to be swapped to use it on the LX200."

Motors were SOLD, gears were still available at $50 HKD.

Sealed Lead Action battery, reliable power solution in the field. Comes with a Panasonic 12V 7.5Ah SLA battery, a charger which will take 12V or 6V SLA, and also a generic notebook transformer which offers 15-24V by using the 12V SLA. Ask for $100 HKD for all three!

You will one day want this tool, it's for creating threads and threaded holes yourself. Virtually new and ask for $50 HKD only (RESERVED for Simon).

JMI 2" -> 1.25" compression ring adapter:-

DIY 43mm male thread afocal imaging adapter:-

Never used JJC EC-2 Eyepiece Extender for Canon EOS DSLR:-

Another custom machined 2" to 1.25" adapter, it's pretty heavy and could be good for balancing light weight 1.25" eyepiece and heavier 2" eyepiece. With two locking screws for added security.

A small 7-14x monocular, good quality for this size.

The Quest for a motor for my Mark-X

2011-11-02T23:58:00.002+08:00

2011-11-18

The motor arrived in perfect condition, however, the shaft coupler is missing and thus I will probably need to buy one myself. On the other hand, I'm delighted to see its quality, the buttons were very nice to press and the pin on the connector to the hand controller is just thick and strong! I'll need to built a power supply for it, and the seller reminds me that it's center negative and it's running at 9V, and thus a 8AA rechargeable will be about right!

After verifying that the motor is indeed working, I shall find a suitable shaft coupler for it and also how to mount it to the Mark-X, finally, I will need to find a replacement crystal oscillator for 126 teeth.

2011-11-13

While waiting for the delivery, I've searched some potential oscillator suppliers:

Mouser, I ordered from them before, trouble free and good range of stuff

http://hk.mouser.com/Home.aspx

RS Online

http://hongkong02.rs-online.com/web/

2011-11-09

The motor and controller is now on its way to me, tracking number: LC308020755US

The seller was kind enough to tell me that the controller is center negative! I should keep that in mind. The first thing which I'm going to do is to put it on the mount, I guess that the shaft coupler will connect without big problem. I shall see if the torque is enough and if I will need to improve the mounting stability, and maybe I will need a local machinist friend to help here.

Secondly, I will need to open up the controller to see how can I modify it from 180 to 126 teeth, I wish and I expect that it will be controlled by a crystal and than I can scale the frequency and buy a new one for it. Exact matching might not be possible but I hope that it will be close enough for me to track like 5-10 minutes at, maybe say, 200mm focal length.

Found a scanned specification sheet of the motor/controller. It has a part number of RMD-2401 and also a model number of CXD-1. In the specification part, it was described as quartz stepping motor and thus I would probably be able to swap the quartz crystal in order to adapt it to 126 teeth. The rated voltage is 9V and the allowance is from 4.5V to 12V. It consumed 160mA and it supports clockwise, counter-clockwise, 4 times speed, and also temporary stop.

From the limited photographs, I believe it would be very easy to mount it to my Mark-X.

2011-11-08

I'll try to buy a Japanese Carton mount motor and attempt to modify it myself. It's the same motor for the Tele Vue system mount which has 180 teeth, since it's a very old model, and I suppose that it will be controlled by crystal and thus, the modification should be relatively simpler for me since I don't need a EPROM writer. Of course, matching crystal is another hard story and an exact match is probably impossible but for tracking like several minutes should be perfectly okay, at least I tend to believe so. Let's see if I can get a good deal.

2011-11-05

There're some very cheap RA motor selling in ebay but the seller never response my request for shipping quote. Not until I click buy-it-now, and then after a few days, I managed to get the shipping but it's 2x of the motor itself! Of course, I will have to cancel it.

2011-11-03

If I were to use gear pairs to match the gear ratio, maybe I should use a off-the-shelf motor with controller rather than to build everything from ground up by myself? At least it seems more reliable?

2011-11-02

I've two existing DC geared motor, it's rated at 5 RPM at 12V.

Tonight, I've tried to apply 2.4V DC to it and it runs, I did a very rough estimate and it's running at 1 RPM at 2.4V... Suppose that I have to get 0.0875 RPM, I will need to slow it down further by using a PWM controller first, and then I will be able to get 0.1 RPM.

To get 0.0875 RPM, I will need a pair of gear, for examples, 28 and 32 tooth gears as recommended by DAVIDG in cloudynight atm forum.

I've to check my existing gear inventory, and see what I should buy.

I've a 35 tooth gear suitable for the motor, so I will need a 40 tooth gear for the worm gear shaft?

I've another 37 tooth gear suitable for the motor, so I will need a 42 tooth gear for the worm gear shaft?

20111031 Moon

2011-10-31T20:41:00.002+08:00

I'm not interested to shoot the sun until I got a better filter. When the sky was getting darker, I saw the bright moon hanging out the window, so why not?

I pulled out my Ranger, set it up on the GOTO Mark-X to take some snapshots. I'm still searching for a suitable motor for it but at the time being, I can still do manual tracking.

I was using my Lumenera LU070M with my Tele Vue 5x Powermate.

First shot was taken at 1833 (GMT+8):-

And then the second one was at 1834 (GMT+8):-

You know, it's just bad!

Jogging under the starry night again

2011-10-21T00:27:00.002+08:00

Went out for jogging as usual, the sky was foggy these days mostly due to air pollutant. However, the sky was pretty black up there near the zenith. Jupiter was hanging up there, shinning as one of the few "stars" in the sky.

Guess what, I immediately think of my newly acquired GOTO Mark-X. My friend has promised to hack one from a EQ3-2 motor for me, but I've got no update since then. I know that I could not rush and I should wait patiently until I got a phone call one day.

During the wait, I could still use manual tracking and I could still think more about how the mounting plate should be made. The simplest design would be a simple slow motion control which allows me to rotate the scope like the DEC axis of any German Equatorial Mount, and the other side would be a ball head which I already had. It would allow high power imaging and probably manual or webcam assisted guiding at the same time, and the ball head side would also allow wide field imaging.

I believe that I won't go for a counter weight unless I've something bigger, a movable 5 * AA battery pack should be used for assisting balancing.

Time to sell that brass counter weight as well?

Now, my miscellaneous sales should include:

1. Shoestring FCUSB
2. Astrotech 1.25" dielectric diagonal
3. Bass counter weight
4. DIY 77mm macro adapter or 70mm f=500mm doublet
5. Small Chinese ball head
6. Metric threading tool set
7. Lumenera LU070M
8. DIY Mark-X mounting plate and counter weight system
9. 5.5" tube ring set

Tell me if you're interested of any of the above items.

20111019 Sun

2011-10-19T13:26:00.002+08:00

Seeing 2/10, transparency 3/10, moving cloud.

Thousand Oaks Type 2+ (full of pinholes), Ranger, Lumenera LU070M, tracked manually with GOTO Mark-X.

From the right side first, the bottom dark one is AR1314, and the bigger group in the middle is AR1319. On the other side that large pale patch AR1323 and 1324.

This is the first time that I use the new Generic Chinese ballhead for imaging, it's strong enough but it's not very good for fine adjustment with high power (480mm * 5 = 2400mm) and I assume that I will need a fine adjustment head like Manfrotto 410 before it could be used for high power imaging. However, my 410 is now serving as the polar alignment wedge.

That ball head is strong enough with my Ranger even at high power, no shifting noticed.

For wide field imaging, I don't have to go anything stronger. For planet imaging, I will need another head but then now I just have my Ranger, no need to concern about high power at the time being?

Features of the Mark-X mounting plate

2011-10-17T23:52:00.001+08:00

Before I make the drawing, I shall write down what I wanted:

1. Light weight and short
2. Able to balance for two equipments of different weight
3. Able to take two (ball) heads
4. Able to attach a mobile phone to aid initial polar alignment
5. Able to mount a battery pack on one end for balancing (e.g. 5 AA rechargeable)

Feature (4) and (5) could be done in an ad hoc manner, not necessarily a design time feature.

Anything else? Here's the first draft:

--

19/Oct:

1) Found a 5 * AA battery box, it could be used to provide 6V DC required by the motor, and therefore, this battery box should be fixed on one of the sides.

2) Should also prepare a way to mount a counter weight shaft there in case I wanted later

3) Or buy something like this:

http://item.taobao.com/item.htm?id=8277650748

cut the upper part and attach to one side of the plate? It will then allow slow motion control.

A trial run of the Mark-X

2011-10-15T12:53:00.000+08:00

We have some sunshine but we have even more cloud. It would not allow good images but it would not stop me from trying out hand tracking with the Mark-X.

This is the setup. The hand tracking knob is very nice, and it's long enough to be controlled by me with another hand on clicking the computer for which the LU070M is driven, hand tracking is easy and smooth and it's definitely good enough for solar or lunar imaging. Planet imaging could be more challenging but then I believe it's also doable.

It's a bit ridiculous that I've a motorized focuser but not a motorized mount. Anyway, I kept the NGF-CM mostly for its 2" capability rather than its motor.

I didn't even open the window mill since I don't think I can capture any good image under this sky condition. Here's the result anyway, and the sun is full of activities!

It's a pity that I don't have an H-alpha filter with me now, not even a good white light filter. Anyway, I will enjoy whatever I have on hand.

Conclusion of priority:

I will buy a good ball head first so that I can use this mount by manual tracking first.
Motor will be next, hacking the motor controller will be even later.
Mounting plate final, not until everything is ready.

Polarscope of GOTO Mark-X

2011-10-15T12:23:00.000+08:00

Today I set it up to test whether the polarscope was properly aligned, and if not, I've to adjust it during day time.

I look through the polarscope to distant objects and found that it's matte.

I pointed the polarscope to the corner of a building and then I begin to rotate the RA axis. It's very smooth and it's a joy to turn it. Obviously, the polarscope is still in great alignment with its axis, there's no obvious moment.

This is workmanship!

Trying out the GOTO Mark-X

2011-10-14T00:06:00.002+08:00

Just put everything on that heavy DIY plate, and it's just a piece of cake for this robust mount.

I cleaned the GOTO Mark-X last night and it looks very fine now.

I've attached a small ball head and a small pan plate to that heavy DIY mounting plate to see how the whole thing works.

Even when the mount is not balance like this, it moves very smoothly. I'm very impressed and really longing to have a motor for it!

GOTO Mark-X

2011-10-12T20:45:00.001+08:00

This is a real Japanese classic. Thank God that I can get one for myself.

The original owner has a DIY counter weight and mounting system for it as shown below. However, it is probably too heavy for me, and so I should go for something else later. I will need to design a simpler and lighter mounting plate for it so that I can attach a ball head to it, and maybe a guide scope on the other side.

After assembling, and they were put on my small Gitzo G106 tripod with Manfrotto 410 head, that DIY setup is really very robust and heavy. I guess it will take a C8 without any problem!

And finally, this is the most important part, the GOTO Mark-X. The slow motion control knob is very nice, and you will feel the quality when you turn it with your finger. This mount is over 20 years old but then it's still functioning great! Smooth like cutting through butter.

I say goodbye to my Takahashi TG-SP II on the same day, and the GOTO Mark-X is acquired through partial trade.

The first thing that I will need to do is to find someone who is willing to adapt a EQ3-2 motor on it for me, the hardest part is to make it compatible with 126 teeth. I don't have the equipments to do it myself.

And then I should probably live with that DIY mounting plate first. Yes, it's heavy but then I should test it first with a ball head which again I may have to buy. I expect the motor plus the ball head would mean over 1K HKD, and I will probably need one more ball head, a polar scope illuminator, and a lighter custom made mounting plate in the long run. But I will keep it simple and stupid at the time being, and maybe even do manual tracking first!

The Sun Remains

2011-09-30T10:16:00.000+08:00

Yes, the sun really remains unchange but I no longer have my solar filter. Even my Thousands Oaks white light is now full of pin-holes.

20110919 Sun

2011-09-19T14:47:00.003+08:00

2011-09-19 14:22 (GMT+8):-

Again with my Thousand Oaks filter but this time not using a telescope nor a Lumenera but my Canon 450D + Kenko 2x + Canon 100-400mm at 800mm effective focal length, five frames stacked and processed...

The sun should be very active these days but my aging white light filter couldn't reveal much of its detail.

20110913 Sun

2011-09-13T14:46:00.001+08:00

AR1289

AR1295

Both taken with my Tele Vue Ranger, Thosuand Oaks Type 2+ Glass (full of pin holes!), and also a generic green filter, Tele Vue 5x Powermate, Lumenera Lu070M.

No tracking, I just count on the fast frame rate of the Lumenera.

FS: Takahashi TG-SP II (SOLD)

2011-09-12T17:05:00.000+08:00

Seldom used Takahashi TG-SP II (less than 10 times in the field), tracking mount for small telescopes and DSLR with lensOriginal Counter weight, hand controller, battery case, V-bracket for Hong Kong, polarscope with paper boxAdditional stuff: German made GP compatible dovetail saddle, bass counter weight, 4AA battery box, USB power cable, plastic case to keep everything inside, ask for SOLD HKD.I should have the original paper box (not photographed)

And if you want a Russian made dovetail, add $300 HKD. It has 1/4" screw for mounting telephoto lens or camera.

SOLD

20110912 Sun

2011-09-12T16:02:00.002+08:00

Got some sunshine today, I pulled out my Thousand Oaks to take a few snapshots. My JMI NGF-CM controller was running out of battery and luckily, I still got my FCUSB around so that I can drive the focusing motor through my PC.

AR1289 takes the center of the stage, with AR1290 scattered into two smaller fragments on top of it... AR1287 was on the far right top corner.

Close up by using a 5x Powermate reveals nothing but dust on the CCD, they were left as tracks...

Without any serious equipments around, all I could do now is to do whatever I can.

Some of my earliest shots

2011-09-08T10:11:00.004+08:00

I've been organizing the files inside my hard drive, and I found a few astrophotographs which I had made long ago... it was taken afocally through my Ranger, by using a DC of my friend.

Guess what? The first one should be Jupiter out of focus, the exposure was about right! The shaky hand and tripod worked together to form this nice image!

And this one should be Saturn! The power was oh-so-low such that the ring couldn't be resolved.

By checking the EXIF, I know that the DC was a FinePix 40i, taken at 2001/2/20

20110824 Sun

2011-08-24T15:50:00.005+08:00

After selling my Solarmax, I have stopped solar imaging for pretty long since now I only have a 10+ years old Thousand Oaks Type 2+. You know, I've been spoiled by H-alpha imaging, CaK imaging and even for white light, I used to do with a Herschel wedge! Anyway, our target is always more important than equipments, and so I pulled out my decade old filter, together with a green filter, as well as my Lumenera Lu070M for imaging.

The telescope used was the Ranger, and now it works with all its 70mm aperture.

At prime focus, i.e. 480mm focal length, 1520 (GMT+8):-

With 2x barlows, i.e. 960mm focal length, 1521 (GMT+8), AR1271:-

Not bad, right? I guess I will continue my solar imaging hobby with this cheap and simple filter.

Sweden Sky

2011-07-29T22:50:00.002+08:00

I've a trip to Sweden with my family earlier this month. I was thinking that I might have some chance to take some good starry skies, but then I missed the fact that there's nearly no dark night in summer for places that high in latitude:

For example, at around 10:30p at night, it looks like this:-

Even when it's 1:30am, it's still blue... exposure like 10 seconds will saturate the whole frame.

A Photograph in the Hong Kong Cultural Center

2011-07-29T22:48:00.002+08:00

This is an event at the end of 2010, it marks an end to life of my solar imaging virtually. This is a joint event of Hong Kong Birding Society and Hong Kong Astronomical Society:

Trip to Shek O with friends

2011-07-28T14:41:00.007+08:00

Planned to go on Friday but the weather forecast was unfavorable, so we switched immediately to go out last night (2011 July 27). Since we're committed to eat our dinner with our own families, we went only until after 8:30pm.

This is the group which I used to observe, they're my hiking friends, my wild camping friends and they're my great brothers in the church. We didn't go out observing together for many years since we have kids at home. After selling most of my equipments recently, I am now using around the same set of equipments like when we first went out observing! So it's a memorial moment indeed.

I didn't bring my camera and tracking mount since I wanted a lighter load despite one of the observing buddies will drive us there. I hurt my foot a little bit when traveling to Sweden so I needed to avoid further injury.

Observing is always fun with friends. We hunted so many deep sky objects under an exceptionally good sky (in Hong Kong standard) when the Milky Way stretched over 90 degrees! It's very rare in Hong Kong these days. It's one of the best skies which I've seen in Hong Kong.

We found all our good old "friends" (observing targets) and we enjoyed sharing the view and of course, the way of finding them. Describing a target is a good way to observe more. Ten years ago, we were using star charts but these days, we have our Android phone and IPad for immediate reference and confirming the targets with the help of various detectors inside these modern mobile phones.

About the equipments:

We have a set of 15x70 and also my Canon 10x30 IS, frankly speaking, I prefer the view of my 10x30 IS for it's just much sharper but not much dimmer. IS is very helpful indeed and I felt in love with it especially with it's huge portability.

The Ranger is still in great shape! In such a dark sky, we could resolve quite many clusters and we could detect any Messier objects that could be found in our charts. Upgrading it by adapting it to a 2" focuser is a great move and now I know why the Pronto was so popular! My NGF-CM works well with the heavy Pentax 40mm XL, and the Pentax is very comfortable with eye glasses or without. It yields over 5.4 degrees of view and it's even wider than all binoculars that we had.

This was the first time that I was really using my 13mm Nagler on deep sky objects and it's again exceptional. I won't sell it without a great reason. Pushing the power from 40mm (12x) to 13mm (37x) is pretty dramatic! The sky was darkened further and the stars were better resolved, some brighter faint fuzzy was rendered with detail to our eyes.

We spent most of the time with the Messier objects around Scorpius and Sagittarius... we visited the Coat Hanger and also we waited for M31 just because we visited it years before.

Visual observation is nice for it's just so simple and fast to pack up all the stuff after around 3 hours of observation.

--

Some further remarks in Chinese (Cantonese):

今次行程超滿足, 也帶來許多舊回憶和舊感覺，我們大概已經十年沒有再特地出去觀星。沿路走入石澳山仔 (大頭洲)，海浪聲和那條山路都很不錯，有一點行夜山的感覺呢！

今時今日我只剩下一支 70mm 望遠鏡，和一支 Canon 10x30 IS 雙筒，這正好跟十年前差不多。不過，現在我那支 70mm 卻可以上 2" 目鏡，這叫它比雙筒更廣闊更好用，我亦多了一只 13mm Nagler，中低倍的表現實在驚人！這目鏡配合 Ranger 實在最好不過。

石澳昨晚的天色很好，銀河清淅可見，應該有超過 90 度，是我有史以來在香港看過最好的銀河！如果進行拍攝，效果應該不錯呢！但因為我上星期扭傷了腳，所以不宜帶太重的儀器，結果還是打消了念頭。後來發現這倒算不錯，因為我們可以花更多時間來觀測，不然只是短短三數小時，恐怕我也只能拍幾張相片而已！

完結時，阿茂竟然拿出幾罐凍飲，叫我實在感動不已！熱天觀星最可惡就是汗水和蚊子，喝一口冰凍的氣水實在值千金。以往觀星受公共交通的班次所限，不能太夜回家，今次阿茂揸車，節省了不少時間，也可以延長觀星時間，真係無得頂。

下次或者都係要影埋相先得！

感激志光哥第日要返工都陪我地出去，又多謝阿茂既車出車入與預備，更要感謝天父預備好天氣，叫我地可以舊地重遊，更與天上的老友重逢 :-)

A Simple Night with the Starry Sky

2011-07-06T09:16:00.005+08:00

I have been reducing my equipments since now I know what I love to do and what I want to do. The sky is very nice these days and so I picked up my stuff and went for a short observation session.

My destination is Pak Tam Chung, not exactly a dark site but it's readily accessible with or even without a private car. By public transportation, I got there at around 1 hour and another hour for coming back, with a total cost of $40 HKD.

I packed everything inside my Fastpack 350 basically. I've my Takahashi TG-SP II, my 450D together with a Samyang 8mm f3.5 and a 50mm f1.8. I didn't bring a lot of lenses since I want to relax and enjoy! Other than that, I placed my Gitzo G106 in a small bag and carry it along side. Oh yes, I also have a couple of star atlas and also my Canon 10x30 IS for visual observation and scanning.

Polar alignment the TG-SP II is not very easy but it does not require great accuracy since I will only use a 50mm lens or a fisheye. That little polar scope works even with one of the cables plugged in, if you plug it both, the objective is obstructed by too much so that you cannot even see Polaris.

Here're the results basically, with a 50mm f1.8 lens, four shots stacked:-

Taken with the fisheye, while the sky was not yet dark, 4 shots stacked. Using a fisheye is harder than imagine in Hong Kong, you will have aeroplane in each shot basically, and you will to keep exposure short and you need luck!

Another one taken with the fisheye, I've to skip a few shots to avoid the aeroplane tracks:-

A picture of myself in front of the fisheye:-

An accidental Iridium flare.

The bus station is just 2 minutes away, I was the only one on the bus in the return trip.

Finally, the Samyang 8mm f3.5 was quite nice, stop it down by one-stop (f5.6 in the next click stop, so it's more than one stop), and stars were basically pinpoint. No focusing required with the huge depth of field, you can trust that infinity mark since the tolerance is huge.

I did scan the milkyway and the whole sky especially the Scorpius area. I didn't check my star charts since I just want to relax, and I just point to what I can remember, and also to scan around like a kid for anything interesting.

This is a convenient place such that kids could go without problem, guess what, I arrived home at 10:00pm... I started packing up my stuff at 9:00pm, and next time, I can pack at 9:05pm or even 9:10pm and I still won't miss the bus.

Skeye for Android

2011-07-01T12:03:00.002+08:00

I'm still using my old fashion WM6 mobile phone but my wife has a new Android mobile.

I just found that there's a free application called Skeye which can show the sky with labels like Google Sky Map, and better yet, there is a aiming circle for this application and it's even built with the concept of DSC (Digital Setting Circle) in mind!

To fix it on the OTA, I've seen in youtube that people made brackets specially for it. And now since I only have a small refractor, I'm thinking that a simple sport armband would work, and it's going to be neat and tidy!

The Samyang 8mm f3.5 arrived!

2011-06-21T16:32:00.003+08:00

I've some paypal balance and I consider it better to buy something than to transfer it to the bank since the charge is high and the conversion rate is bad.

I ordered it last Thursday and it arrives today (Tuesday), so it's very quick. The seller does not give me a tracking number and I could find one on the package, so if they will send it to me, it's definitely better.

The items were well packed, but the lens cleaning set has some of its fluid leaked maybe due to the pressure from other items. The box of the kit was partially soaked and some of the papers inside the box was somewhat wet as well, luckily, the lens was not affected at all.

The brand name on the box was Rokinon but the manual has Samyang, so it's an OEM product. The lens was built like tank with tight tolerance. The focusing ring was smooth and the aperture ring snaps into place with clicks. Focusing was easy due to its huge depth-of-field even at f3.5. No focusing was required if I stick at f8 or something like that. The focuser is butter smooth, a feeling of high quality focuser, feel like L class lens. No joking!

The metering of my 450D tends to give brighter image, but then I found similar issue even with my telescopes attached. Simple exposure compensation (AV) could fix the problem easily.

I never played with such a wide lens and 10mm is the widest I tried. The huge field of view and the fish-eye effect was immense! I guess that I will need to spend a lot of time with it to get use to it. The first thing that I wanted to do was definitely a wide field imaging on a good starry night but then since a typhoon is coming, I will not have a chance to do so any time soon.

Observing with the kids

2011-06-20T21:02:00.004+08:00

The plan is simple, the kids wanted to see the Saturn! Therefore, we don't have to travel but we can truly grab-and-go! I've my Ranger on Gitzo G106 with Manfrotto 410, I also have a 40mm Pentax SMC XL as a finder (over 5 degrees of view) and a 20mm Widescan (24x) and also a 5x Powermate (120x).

I was soon misled by Arcturus which is similar in coloration! Without much sky to deal with, I swing my Ranger around to point at Arcturus thinking that it was Saturn... it's nearly the zenith and thus I had a hard time to locate it. After fooling around for nearly 5 minutes, I managed to get it into the view... you know, using a 410 head suffered from the Dobsonian hole issue for target near the zenith. Got it but then it's nothing but a star!

Being cheated, I asked my sister to use her mobile phone to locate Saturn... we were surprised to see that it was partly hidden by the bright spotlights of a nearby building! I swing my Ranger there, immediately blinded by the spotlight but still, it's not hard to point at the Saturn. Pushing the power to 120x, the view was not affected at all.

The kids took turn to look into the eyepiece. I guess some managed to see, but some with doubt. I guess I should keep an easier eyepiece for the kid, like a cheap Plossl, since Widescan or even Nagler could be quite hard to look through due to their sweet-spot and blackout issue. However, the wider field of view should be nice for a non-tracked mount.

20110619 Saturn

2011-06-19T22:04:00.005+08:00

Last time I was capturing Saturn with a fixed tripod, this time, I used my TG-SP II in the hope to capture a longer AVI or even push the image scale further.

First of all, I setup everything with my Pentax SMC XL 40mm in place. I found the setup is too heavy for the original counter weight, so I've used the heavier local made counter weight and it tracks very nicely.

Saturn was barely non-stellar in this low magnification (12x). I balanced mount roughly and then I proceed to a 20mm Widescan since it's roughly parfocal with my Lumenera. With the visual view, I couldn't see any problem on the balancing but I doubt when it comes to imaging. Then I added my 5x Powermate into the optical chain and I soon realized the issue on balancing! The mount was not tracking well and the slow motion control was not working very well, either.

Since I don't want to re-balance everything, I replace the Widescan with my Lumenera and with some major effort, I finally managed to fit Saturn into the view but then I found it drifting like without tracking. I also found that this setup was a little bit too heavy for my Gitzo G106, maybe since I've a 410 head and a Takahashi wedge so that the center of gravity was higher than usual.

It's a failed attempt.

Anyway, I've still capture two clips, and the first one was at 7.5fps (i.e. 1/8s with medium gain) and the second one was at 15fps (i.e. 1/15s with high gain).

2158 (GMT+8) at 7.5fps:-

2159 (GMT+8) at 15fps:-

The lower power visual setup with Pentax SMC XL 40mm:-

The imaging setup:-

Note the large weight difference!

Inventory Checking

2011-06-18T10:36:00.002+08:00

I did something similar on November 10, 2010.

Telescopes/Objectives:

1. 70mm f=500mm achromatic objective mounted with 77mm thread
2. Tele Vue Ranger
3. Canon 10x30 IS

(1) is for sales at $300 HKD, useful as a great closeup lens for camera lens!

Eyepieces, Barlows and Diagonals:

1. Pentax 40mm SMC XL
2. Tele Vue Nagler 13mm Type 6
3. Tele Vue Powermate 5x and 2x Barlows
4. Japanese Widescan Type III 20mm
5. Japanese Ortho 7mm
6. Tele Vue 1.25" mirror diagonal
7. Chinese 2" mirror diagonal
8. Astrotech 1.25" dielectric diagonal

(8) is for sales, it's very new with box, $500 HKD.

Mount/Tripod:

1. Gitzo G106
2. Manfrotto 410
3. Takahashi TG-SP II

Camera and accessories:

1. Lumenera LU070M
2. JMI NGF-CM with Tele Vue Ranger adapter
3. Thousands Oak Type II+ for Ranger

(1) is available for sales, $2700 HKD.

20110616 Total Lunar Eclipse

2011-06-16T03:01:00.004+08:00

Woke up at 2:00am, the mount was already there in place, just need to put on the camera and it's done.

The above is my equipments: Canon 100-400mm f4.5-5.6L with Canon 450D, a timer release cable is attached and a USB cable was also attached for downloading images for Facebook update. The timer release is not very useful since the moon was blocked for most of the time. Takahashi TG-SP II was used for tracking and it's powered by the USB port of my PC through a DIY cable, it's just convenient! No need transformer, no need to charge any battery, etc! The whole setup was placed on my Gitzo G106 with a Manfrotto 410 head to fine tune the polar alignment.

I also have my Canon 10x30 IS for visual observation, I did something similar during the total solar eclipse in 2008 and I can observe with my right hand holding the binoculars and my left hand to press the shutter release.

While setting up my Canon 100-400mm, I took my 200mm f2.8 to have some handheld snapshots first since the cloud was getting in.

When the tracked setup is ready, things are much better. As the moon gets dimmer, we will need some form of tracking since you're doing several seconds of exposure. Originally I planned to do 800mm with a 2x Kenko but then the sky was very bad with thin cloud, so f/11 would be too much!

Cloud was moving around, thick and thin, large and small...

The cloud amount was increasing overall, so some cloud breaks could be as short as several seconds, so you will have to adjust the mount, etc. Spot metering was used, and so you will want the bright part of the moon to be at the center of the frame!

Friends from local amateurs were reporting their situations and some reported rain!

The weather conditions seemed highly localized, and later we found that we could observe far more in some lucky locations!

This is the last one that I managed to capture.

I waited more than one hour after this shot and we had heavy rain and wind.

Finally, I found the moon could be blocked by distant building before I packed up my stuff.

Believe it or not, this is the first total lunar eclipse that I managed to observe, but then I still couldn't see the real totality. Good me luck next time in December if I managed to catch a chance!

Tele Vue Ranger with NGF-CM

2011-06-14T17:18:00.001+08:00

I've ordered a 2" filter thread extension tube for my 2" diagonal so that it could serve as a mini-drawtube which effectively extends the focus travel range of my transformed Ranger which has the original focuser removed and replaced with a short focus travel NGF-CM. Such a combination works with all my existing eyepieces from a 2" Pentax SMC XL to a 13mm Nagler with 2x or even 5x.

Previously my Ranger was used solely for solar imaging and since I used it with a reducer, so I really cared more on the in-travel. Now, it's my only telescope so I wanted to make it more versatile.

Now it's also capable for visual work!

Jogging under the stars!

2011-06-14T17:14:00.002+08:00

Last night I went jogging at night as usual. In Hong Kong, you really couldn't jog under a lot of stars, but when the sky was clear, you could see some brighter constellations. It's refreshing enough to run, and the stars drift slowly along with time and so you know life is moving :-)

20110612 Moon

2011-06-13T07:48:00.003+08:00

After the short and brief pass-by of a small typhoon, the sky was cleared except a thin layer of mist. The moon shines through the windows, casting shadow on the floor.

I picked out my Canon 450D, 100-400mm and a 2x to have some very brief observation and imaging on tripod. The moon was too dim (the mist was too thick!), so that exposure for the moon would be over 3s!

Anyway, the view through the finder is fine enough.

20110531 Saturn

2011-05-31T00:25:00.005+08:00

Didn't really take any picture of Saturn for very long, now I only have my Ranger again and the iOptron Cube was sold, so I've to go back to hand tracking with my Manfrotto 410 geared head.

To my surprise, I can still manage hand tracking at up to 2400mm manually... guess what, tracking and focusing at the same time is not a simple trick, it takes patience and a lot of patience...

Still love the raw and small image from the eyepiece, it's lovely and enjoyable, the wonderful thing of amateur astronomy. Not even Hubble images can rival!

0010 (GMT+8), with 2x barlows at 960mm focal length:-

0014 (GMT+8), with 5x powermate at 2400mm focal length:-

Taken with my lovely 13+ years old Tele Vue Ranger!

Telescopes that you owned more than once

2011-05-24T16:34:00.002+08:00

Equipment comes and goes, it's a matter of fact if you stay in amateur astronomy for more than a couple of years. During the buying and selling, you might find that you could actually own a telescope or a certain piece of equipment more than once. I've a few such experiences.

1. Borg 45ED

Strictly speaking, I didn't own it twice, but I owned one Borg 45ED and one Borg 45ED II. They're very similar and the only difference is the focal length but you cannot tell from their appearance.

It's unique in the sense that it should be the smallest APO in the world. It's small and it's versatile. I used them mainly for solar imaging with my Solarmax 40, and it's useful for guiding and some real wide field scanning. High power observation is not useful due to the very limited aperture. It's so portable that you have no reason to keep it at home for whatever trip.

2. Celestron C5

This is a very unique telescope. It's an unique combination of size, weight, portability and performance and price! You cannot get any better than this given its portability. You can do some really "serious" work with the advanced video cameras these days, for example, my C5 Jupiter taken with a DBK exceeded my C8 Jupiter taken with a ToUCam Pro!

It's so light that any mount would do the job.

3. Various Cameras

I have owned more than five ToUCam Pro, some keeping their life as a color camera and some were modified to black and white. I sold them all until I bought some DMK/DBK.

I have owned three DMK/DBK, and they're really very nice cameras.

I have owned many Lumenera LU070M, they're perfect for their price, and I bought them as a batch from a closed research lab. They exceed the performance of a similar DMK with the higher dynamic range, bigger chip/pixel, etc.

Items for Sales

2011-05-21T22:01:00.004+08:00

Local (Hong Kong) buyer preferred, price also listed in HKD. If you're interested, please let me know, foreign buyers please ask:

1. Celestron C5 OTA in silver color (i.e. Nexstar) [HOLD]

with Vixen style dovetail, 1.25" visual back, 25mm Celestron Plossl

$2500 HKD, optional Astrotech 1.25" dielectric diagonal available at $300 more.

2. Lumenera LU070M with integral 1.25" adapter

640x480 monochrome 1/3" CCD (bigger than DMK 21) [HOLD]
12-bit (better than DMK 21 again)
60 fps
USB 2.0 Interface
Ready to be used with 1.25" focuser, comes with a wide field lens

$2700 HKD.

3. Canon 100mm f/2.0 USM with hood and Hoya filter, no box [HOLD]

Show sign of use, some dust inside the lens but does not affect performance, $2000 HKD.

2011 May 16 Goodbye H-alpha Solar Imaging

2011-05-16T18:09:00.003+08:00

This morning, I packed up my Solarmax 40 with BF10 + reducer, the iOptron GPS Cube as well as the Lumenera.

They were passed to someone just a few minutes ago.

Thank you for their services, and they brought some really great moments for me. I love to play with them under the sun, and I managed to get a picture good enough to be shown in a local exhibition, and a US dealer even picked one of my pictures in their printed catalog :-)

20110509 Sun

2011-05-09T15:01:00.002+08:00

While no one show interest in my solar gear, I will continue to use it. The sky is not very good today, we have cloud floating around and the transparency is like 7/10 when it's cleared, seeing like 3/10.

1440 (GMT+8):-

1441 (GMT+8):-

Astromart...

2011-05-09T09:10:00.001+08:00

They want money from me again, and that's what I saw this morning:-

"You have run out of sponsor ads"

"Your account is required to purchase support ads to use Astromart. Click Here to go to the featured ad purchasing page."

I believe that I paid no long ago, but then I was asked to pay again... Astromart tax again? I wonder whether I will pay... so if you have response my ad. there, let me know via email or some other means. Thanks.

Why Solar Observation?

2011-05-05T20:58:00.000+08:00

A few obvious reasons:

1. It's the most obvious object in the sky.
2. It's very dynamic.
3. It requires only moderate equipments.
4. It can be done in any place for it penetrates light pollution very well.
5. I want to sleep at night for most of the time.
6. It's simple to do.
7. It's just beautiful!

20110413 Sun

2011-04-13T23:11:00.001+08:00

This is the first time that I setup my 2nd C5 for imaging on the iOptron Cube, I don't know whether the problem was from high frequency seeing or it was the vibration from the mount, but then at 1250mm, I guess the chance for tracking vibration was not very likely.

20110410 Sun

2011-04-10T17:25:00.003+08:00

I managed to get back home early enough to catch some sunshine! No more aperture blocking since I've moved my Ranger to the hacked side of the iOptron Cube. The hacked side is not as stable as the official side but then it works far better in the summer.

1526 (GMT+8), with reducer:-

1529 (GMT+8), with 2x barlows:-

1530 (GMT+8), with 2x barlows:-

1531 (GMT+8), with 2x barlows:-

Poor seeing at 2/10, transparency like 4/10. The sun is more active these days and it's always changing and a fun to capture.

20110409 Sun

2011-04-09T12:59:00.003+08:00

Summer is coming, and the sun will be travelling westward so that I won't be able to shoot the sun from inside my home without some adjustments. Today, I've to open the other side of the window to shoot and the angle of view is very strange making centering of the solar disc a bit more difficult. Right now the solar disc was being blocked partially by the upper side of the window and so I'll have to wait around 30 minutes I guess (it's now 1256 GMT+8).

There's a large QRF as I can see with the partially blocked image from the display right now. A medium sized prominence loop could be detected as well.

Since I've to go out, I really have no time to wait for complete clearing of the blocked aperture, so here we go:

Taken at 1322 (GMT+8).

20110402 Indoor Stargazing

2011-04-02T20:40:00.004+08:00

Pulled out my C5, the first task is to tune the collimation. I didn't do that for quite long and so it took me for more than 10 minutes... after that, it's good enough for casual observation, but for planet imaging, it would take a little bit longer to refine further.

The iOptron paddle is very user friendly, this is the very first time I use it on stuff other than the sun! Despite it has no numeric keypad, navigation is very fine and easy. On choosing deep sky objects, let say Messier objects, it will skip all those numbers which were not visible automatically and that speeds up the process a lot. You don't have to go through 0-9 one by one. Choosing a named star is similar. Choosing Sirius involves only a few key presses, I love this mount even more now! Tracking is very stable at 96x, no noticable vibration at all. GOTO is pretty accurate especially when you have a bright star around for "sync".

M42 is a very fine sight despite the heavy light pollution and the poor transparency, the fuzzy patch is very small and dim, but then the trapezium splits very nicely with a 20mm Japanese Widescan. M41 is good with a 13mm Nagler, it is not as great when obsering with a 20mm Japanese Widescan due to the serious light pollution and hazy sky. The sky was darkened with the higher magnification and it certainly helps.

--

Here's some Chinese notes:

好耐無試過室內睇星, 有薄薄一層雲, GOTO 去 M41, 咩都見唔倒, GOTO 去 Sirius 再 sync 返台 mount, 再 GOTO 返 M41, 低倍目鏡見倒幾粒星, 換高倍少少, 再深呼吸少少, 即刻成地都係星星!! 果種見倒與見唔倒之間既感覺正係肉眼觀星既樂趣~

First night of my 3rd C5

2011-03-31T23:55:00.002+08:00

The first one was sold but I soon wanted to get another one.

The second one was a lemon and I soon returned it.

The third one has arrived for a few weeks maybe, but I just managed to get some star lights to fall on it. I colliminated briefly and stars were pinpoint.

Cloud moved in and out so that I cannot really fine tune the collimation, or I can really observe with it. But at least I know it's not a lemon. The last one could not form any decent image even for day light target.

Wish that I can have time to really try it out, it shall stay with me for a pretty long time.

20110321 Sun

2011-03-21T15:35:00.003+08:00

Thank God for the sunshine today, it has been so wet these days and the sunshine should drive the humidity lower.

Prominence activities were pretty good today, and a small but strong group was at the bottom and a pretty long one could be seen near the top. AR1175 could be seen clearly and signs of new (or remnant?) active region could be seen over the solar disc.

Seeing pretty poor at 2/10, transparency 3/10.

1522 (GMT+8):-

1523 (GMT+8):-

Closer up:-

1525 (GMT+8):-

1526 (GMT+8):-

1527 (GMT+8):-

20110314 Sun

2011-03-14T15:48:00.003+08:00

I tried to setup my telescope twice today, the first attempted failed since cloud covered after I setup my stuff... After seeing the completely covered sky, I packed up my stuff... and then after around half an hour, sunshine came in my home and I setup my stuff again.

Seeing 4/10, transparency 2/10.

1458 (GMT+8) with reducer:-

1500 (GMT+8) with 2x:-

1501 (GMT+8) with 2x:-

1502 (GMT+8) with 2x:-

1503 (GMT+8) with 2x:-

20110307 Sun

2011-03-07T15:34:00.004+08:00

The sun is very active today, we have several big active regions around and among them, I have taken two close-ups which includes AR1164 and AR1166.

Seeing 3/10, transparency 3/10.

1523 (GMT+8):-

1526 (GMT+8) with 2x barlows:-

1527 (GMT+8) with 2x barlows:-

20110228 Sun

2011-02-28T14:49:00.002+08:00

This is the last day of Februry 2011, time is going very fast but cloud had been moving slow. I finally got some sunshine today.

AR1164 is going strong, seeing 6/10, transparency 4/10.

1427 (GMT+8) with reducer:-

1430 (GMT+8) with 2x barlows:-

Another C5 is coming

2011-02-28T13:58:00.003+08:00

The tracking service of Hong Kong Post reveals that the package has arrived Hong Kong. I might be able to fetch it on Wednesday morning, it is an insured parcel and so I'll have to go to take it myself and it won't be delivered to my home.

It's again a Nexstar gray tube model, with a Vixen compatible dovetail. I guess it's still a Made in USA model. I'll also get a 1.25" visual back as well as a Astrotech dielectric diagonal, a 25mm eyepiece is included as well.

Actually, I don't need that diagonal and eyepiece, so if you're interested, let me know and we might be able to come up with a good deal :-)

20110207 Sun

2011-02-07T15:21:00.003+08:00

I've been out of town for a couple of days, and I have some observations there for a few nights. The sky there was not particularly good, but I've conducted some low power observation with my Canon 10x30 IS as well as a few short exposures with my Canon 450D on my Takahashi TG-SP 2. I'll write some separate entries for them later.

Back to the Sun, AR1153 is around when I observe today. Seeing 3/10, transparency 5/10. No big activities.

1521 (GMT+8):-

Going for a family trip

2011-02-01T21:42:00.005+08:00

Chinese New Year is coming and this is a special one for me since I'll be going for a trip with my family. We're going to some villages and hopefully I'll have some better sky than Hong Kong. Since I'll be going with the kids, I couldn't bring anything heavy. What I will take are the following:

1. Gitzo G160 with Manfrotto 410 head
2. Takahashi TG-SP II without counter weight
3. DIY battery box with 4 AA Sanyo eneloops
4. Canon 450D with kit lens, timer release
5. Canon 100mm f2.0
6. Canon 10x30 IS
7. Pocket Star Atlas, S&T Publishing

The TG-SP II is small, and it can take my Canon 450D without any additional counter weight, the motor compartment is a built-in counter weight and I found that it's heavy enough to balance the 450D with either the kit lens or the 100mm f2.0! Also, since it takes only 6V, and I found that it works without problem at 4.8V so power supply is not a problem as well. Visual observation would be done with a Canon 10x30 IS.

Weather forecast is favorable:

http://www.haotq.com/d7_quanzhou.html

20100131 Sun

2011-01-31T16:03:00.002+08:00

Lunar new year is coming.

Seeing 3/10, transparency 3/10.

AR1150 is probably the most attractive feature despite it's small. My elder daughter Alby came and had a look with the 20mm widescan Type III, she can tell me nearly all the features that I've captured. I also had a look with my 13mm Nagler Type 6.

20110127 If there's less cloud

2011-01-27T16:59:00.003+08:00

If it's less cloudy, it should be a very nice view!!!

1628 (GMT+8), that filament extends outward to form a complex structure!

1630 (GMT+8):-

20110124 Sun

2011-01-24T15:56:00.001+08:00

Cloudy but I got a short break without cloud, transparency 2/10, seeing 1-2/10.

1450 (GMT+8) with reducer:-

1453 (GMT+8) with 2x:-

1456 (GMT+8), with 2x:-

Quite interesting sun today with two active regions (1147 and 1149), some QRF and a long and thin prominence.

20110115 Sun

2011-01-15T12:08:00.005+08:00

Seeing like 1/10!!! Worst that I've even seen, transparency 5/10.

1208 (GMT+8):-

I only had ten minutes to setup, shoot and tear down everything today. The seeing is so bad that even at such low power, the sun looked like exactly a 20 cents Hong Kong coins. The video:-

Ultrawide Lenses

2011-01-15T10:38:00.003+08:00

I've three candidates in my mind. Maybe it's time for me to really sit down to list all the respective pros and cons:

1. Canon 10-22mm

- Great performance
- 22mm is long enough to replace the kit lens
- $5xxx HKD new, $4xxx second hand

2. Tokina 11-16mm

- Fast aperture, FAST!
- Great performance
- 16mm not quite enough to replace the kit lens
- $4xxx HKD new

3. Sigma 8-16mm

- Widest among three, WIDE!
- Great performance
- Again not quite enough to replace the kit lens
- $4xxx close to $5000 HKD new

It seems like the verdict is among whether I want it to REPLACE the KIT lens, I want it FAST or I want it WIDE!

20110113 Sun

2011-01-13T15:18:00.003+08:00

Cloudy, windy and cold these days, finally we got a little bit sunshine today.

1444 (GMT+8) with reducer:-

1449 (GMT+8), with 2x barlows:-

Cold weather these days forced to rethink my preference. Frankly, I love cold weather much more than hot, but you know, life really needs warmer weather in order to survive well... So?

Our own star is the source of heat, and thus an important powerhouse for life here. I should love it more than to hate it during the hot summer, or needless to say, under cold winter.

Having said that, I still love winter more.

ebay buyer protection

2011-01-13T11:36:00.003+08:00

It covers the cost of the item as well as the original shipping, but the problem is that, you will have to pay the return shipping.

Somehow it's pretty unfair if it is due to unreliable description of the item. In my case, it was an abused C5 telescope. It's corrector might be from another scope or it is just a piece of plate glass. It came loose and obviously someone had disassembled it before without properly return it into the place. The orientation of the corrector with respect to the primary is critical and I saw no mark left on the corrector, and I've tried to rotate it for sharp image, but I found that I couldn't. The rubber ring around the secondary mirror cell is also broken. When I tried the scope on the moon, I could see double image, no matter how I rotate the corrector or collimate the scope, it won't go.

Returning this junk scope costs me more than $40 USD but I've no choice if I wanted to get back $2xx USD. Buying heavier item which could incur a big return cost is not something wise from ebay transaction.

Celestron C5 OTA

2011-01-10T17:46:00.006+08:00

This could become harder and harder to come by.

What I got ia s silver tube C5 OTA with Starbright Coating, it comes with a Meade 2" SCT mirror diagonal with 1.25" compression ring adapter. A 9mm Kellner eyepiece is included. The diagonal has a "Japan" label on it, and that 1.25" adapter has a compression ring inside, not bad it seems.

The focusing knob is a bit tight and it has some rough points throughout the whole travel, but then when I loosen the screws a little bit, the problem is gone.

This is the worst part, as you can see from this photograph, part of the rubber ring around the secondary cell is missing. It indicates that the corrector was once removed from the tube for some unknown reason.

I guess that I've got a good deal but then I found many issues with this OTA. The most serious one is that the retaining ring on the corrector is pretty loose so that the corrector can rotate around the cell, bad thing indeed! You need critical alignment for the corrector and the primary!

I've decided to return this scope to the seller. Just waste money for the shipping, sad.

What's still good for this particular transaction is that, I managed to try this OTA on my iOptron and I found that it could handle it without any problem! So, maybe I can go to search for another C5 in the future?

--

I've been struggling for the refund and it's more complicated than I once thought. When the package arrived the seller, he still refused to refund me but he said that the package was damaged during shipping. However, as I found that he has signed to accept the package and that means, the package should be free from trouble as from the outside packing. After the postman left, it's actually hard to tell whether the scope was broken during shipping or intentionally done by the receiving party. Frankly, that scope is unuseable in the first place and therefore, it has zero value and thus, it's impossible to claim any insurance indeed. It feels like you're sending a junk but then you said it's "damaged" and ask for compensation! I believe that it's more like cheating and so I've refused this request promptly and asked ebay customer support for help.

ebay is fast and reliable, I got my refund this morning. Despite I've lost some money for the return shipment, I feel good about ebay who stands behind the deal.

A Heliocentric Birthday Greeting

2011-01-09T18:41:00.002+08:00

Among so many birthday greetings which I've received a few days ago, the following is the most astronomical:

"Congratulations on another trip around the Sun!"

And this is actually the underlying physical meaning of a birthday. We will usually take the biological one, but this astronomical/physical meaning could be a nice alternative for amateur astronomers.

20110108 Sun

2011-01-08T13:22:00.002+08:00

Some real nice activities... seeing 4/10, transparency 3/10. AR1140 and 1142, with some long QRFs.

1226 (GMT+8), with reducer:-

1229 (GMT+8), with 2x barlows:-

1231 (GMT+8), with 2x barlows:-

1232 (GMT+8), with 2x barlows:-

20110107 Avian Occultatons of the Setting Sun

2011-01-07T21:11:00.003+08:00

This event is highly predictable since the last time I visited that site by random during the last partial solar eclipse. It's pretty close to my home and thus easily accessible to me.

I don't know what's the reason behind when then when it's about sunset, the birds will come from nearly all directions! Those birds were mostly not there even 20 minutes ago!

Anyway, it's a nice view.

20110101 Sun

2011-01-01T12:34:00.004+08:00

Happy new year!

The sun greets us with a little bit more activity, wish that we have a strong sun in 2011! Seeing 3/10, transparency 5/10.

1223 (GMT+8):-

I'll still use my good old Solarmax 40 with BF10 until it was sold one day.

Selling Solarmax 40 with BF10

2011-01-01T10:24:00.006+08:00

I'm trying to see if I can sell it. What's included:

1. the original case
2. Solarmax 40
3. BF10
4. a 1.25" reducer for BF10 ($99 value!)
5. Machined and black anodized adapter for Tele Vue Ranger (77mm thread)
6. Airmail shipping with tracking number to the US or similar destination

If you're wondering why I'm selling it, I would say that I'm looking for an upgrade.

I'm the second owner of this wonderful little filter and I guess that I've owned it for over 3 years and it's still going strong as you can see from this blog. To me equipments are to look through but not look at.

Price $800 USD, no paypal fee. Photographs below:-

Solarmax 40 and BF10:-

BF10 on the red side, also the reducer, the 1.25" filter thread extension tube on the left of the reducer is not included in this deal:-

BF10 on its blue/green side:-

Solarmax on the front:-

20101231 Sun

2010-12-31T14:18:00.003+08:00

Solar imaging is so addicting in the sense that you can always observe differences, and you can nearly always shoot when the weather allows, and you don't have to go to any dark site, you can do it in your home, and you can do it only with a short period of time.

Very bad seeing 3/10, transparency 3/10.

1401 (GMT+8):-

1402 (GMT+8):-

Poor seeing messed up any fine detail.

20101230 Sun

2010-12-30T16:11:00.001+08:00

The sun continues to shine with low activity, not much change except that large prominence was shrinking.

Two low power shots with reducer:

1520 (GMT+8):-

1521 (GMT+8):-

Higher power shots with 2x barlows:-

1524 (GMT+8):-

1525 (GMT+8):-

1526 (GMT+8):-

Seeing 2/10, transparency 5/10.