Tuesday, January 30, 2007

Astrophotography with DMK camera

Other than planet/lunar/solar imaging, the DMK can be used to do some simple deep sky imaging as well, recently The Imaging Source has released a long exposure firmware for their excellent high frame rate 1394 cameras, and it further improves its capability for deep sky imaging.

In order to keep the exposure short, one will want to use fast telescopes. DMK cameras have very small CCDs like 1/4" or 1/3", and they come in a package with c mount, the natural choice would be c mount lenses. In ebay, we have a lot of good quality c mount lenses available at very competitive price, to give an example, a 75mm f/1.8 prime lens could cost as little as $20 - $30 USD, don't get it wrong, those were good quality lenses, made in Japan! Notable brands are Cosmicar (Pentax), Fujinon, Compustar, to name a few.

With the small CCD chip, these lenses are far more compact than DSLR lens, and it makes everything so portable. The downside is, you have a very narrow field of view unless you have really short lens, like 4mm.

These lenses come in two mounting, one is C mount and another one is CS mount. With CS mount, your lens got to mount closer to the CCD, so if you got a CS mount camera, you can use C mount lenses with a very short extension ring (too short that I won't call it an extension tube).

Here's my collection of c mount lenses:

They are:-

Cosmicar 150mm f/3.2
Fujinon 75mm f/1.8
Fujinon 25mm f/1.4
Cosmicar 8mm f/1.5

and also a Vivitar 1.5x convertor.

In addition to them, I will also use my Borg 45ED II with a 0.5x binoviewer corrector with an extension tube. One may even use moving primary SCT with a f/3.3 reducer, I'm going to try it with my C5.

Comet hunt again

I've acquired a 52mm IR pass filter, so I tested it today after lunch, armed only with my IR insensitive DC (KM Z5), nothing could be seen, all images processed fairly heavily:-

An unprocessed shot to show sky condition, pretty good for local standard:-

A shot to show the diffraction pattern of the damaged/recessed dots of the filter:-

Photographs of the filter, showing the recessed dot on both sides:-

20070129 M42

Tonight, I tried to use the Borg 45ED II with reducer and extension tube, focusing was done by far away terrestial object and it's so close to infinity so that when I slew to the sky, I could immediately see pinpoint stars. After slewing around, I managed to get M42 in the view. Fine tune the focus with trapezium, and I've now taking images.

A series of shots taken with 548 gain and 2.872s exposure were conducted as the core.

And then a series of shots taken with 648 gain and 19.472s exposure were obtained as the extended location, limited by polar alignment accuracy inside my home.

Photograph of the setup:-

Push a bit more:-

Monday, January 29, 2007

Solar Equipments

Solarmax 40, Borg 45ED II, JMI NGF-S, BF10, 20mm Japanese Widescan Type III:-

NGF-S can be controlled via the original hand paddle or the Shoestring Astronomy FCUSB.

1.25" APM Herschel Wedge, with a computer heat sink attached:-

Sunday, January 28, 2007

20070128 H-alpha and White Light (AR940 and interesting prominences)

Poor seeing (2/10) kills any smaller detail, and poor transparency (2/10) kills all the contrast.

1501 full disc composed by two separate exposures on prominence and surface detail:-

1507 close up of AR940, with 2x barlows, Borg 45ED II:-

1513 another close up in back/white:-

1514, 1516 prominences with 2x barlows, Borg 45 ED II:-

Full disc mosaic stitched from 3 * 3 raw frames, click to see full size, this is about what a SM40 can do in terms of resolution as by calculation, but this shot is limited by seeing and transparency, sounds like it's not worth to upgrade in Hong Kong, since we are more limited by the air pollution than equipments, we can see seeing/transparency are both varying while the individual shots are taken:-

1548: White Light Full Disc, Borg 45ED II, DMK 31AF03, APM Herschel Wedge, ND3 + Polarizer:-

The orientation of the solar disc is changed since I am using a polarizer to reduce the brightness (it's already minimum gain with 1/10000s exposure, but still over, so got to add the polarizer).

Saturday, January 27, 2007

20070127 M42 Borg 45ED II with DMK 31AF03

First attempt to use DMK with my Borg 45ED II, I found there's some very slight image shift in the JMI NGF-S when the focus direction is reversed, but it's very slight, around a few pixels at this image scale, acceptable to me.

Focal reducer is pretty hard to use, since it's hard to re-focus after fixing the reducer in place. So, I'm doing these without reducer, i.e. at its native focal length of 325mm.

With my very roughly polar aligned LXD55, star remain absolute pinpoint at up to only 16.36s, and I could see slight elongation at 19s+.

Transparency remained quite low at 6/10.

The 16.36s clip (with 30+ frames) is spoiled for software problem, only the 19s * 5 survive:-

20070127 H-alpha and White Light

H-alpha obtained with Coronado SM40/BF10, Borg 45ED II with JMI NGF-S, DMK 31AF03, with and without Tele Vue 2x barlows.

White light obtained with Takahashi Sky90, Tele Vue 2x barlows (ND3 + Polarizer) and 5x Powermate (ND3 only), APM 1.25" Herschel Wedge.

A new active region AR930 is found on the solar limb.

Seeing 2/10, transparency 3/10, the poor seeing kills any small detail and the low transparency really hurts the contrast as well. Sorry for the poor image quality.

1212 (HKT):- a full disc made from a single exposure, prominence and surface detail processed separately:-

1213 (HKT):- a full disc made from two exposures, prominence and surface detail take separately and processed separately, too:-

1218 (HKT):- 2x barlows, close up of AR940:-

1220 (HKT):- 2x barlows, close up of some very fine but small prominence:-

1233 (HKT):- Sky90, Herschel Wedge, 2x barlows:-

1241, 1244 (HKT): Sky90, Herschel Wedge, 5x Powermate:-

1247 (HKT): same as above, different coloring scheme:-


Thursday, January 25, 2007

JMI hand controller vs. FCUSB

Last night, I found the JMI hand controller is a bit too coarse in fine focusing, for visual observation, it's okay, but for imaging, I found it a bit easy to overshoot the exact focus.

Previously, when I said it's too slow, but after some usages, I found it's actually too fast, even at the slowest setting on a very old 9V battery.

On the other than the FCUSB from Shoestring Astronomy is finer, got to use it more often whenever possible!

Wednesday, January 24, 2007

20070124 Earthshine, Occultation

Borg 45ED II with NGF-S on LXD55, DMK 31AF03 at prime focus, they're sorted according to the time:-

2011 (HKT), this is the mug shot style exposure (1/38s), to show what we would see with our eyes:-

2013 (HKT), this is to increase the exposure to see background stars, notice that there's a bright star close by, just finished occultation apparently, it's pity bad that I missed the event, you could see the original video below as well:-

2013 (HKT), the video which is processed and stacked by Registax, this one is compressed and you can see the moon receding from that star, it shows that the moon travels faster than the background sky:-

2016 (HKT), to increase the exposure further (~2s) to pick up even more background star, but the bright side of the moon become overwhelming bright to saturate neighbour pixels so that the star in the above picture disappeared by the excessive glare; we can see a little bit of the dark side of the lunar disc, by Earthshine:-

2015 (HKT), further pushing the exposure (4s) to show the dark side of the lunar disc by Earthshine:-

Thin cloud floating around, seeing moderately to poor.

Finally, we did some visual observation. With a 40mm Pentax SMC XL, the wide field of view is immensing, with a lot of sky background, contrast is great, the image is sharp but pretty small at ~8x only. No false color is detected even at the limb, color fidelity is the strongest thing for this eyepiece.

We pumped up the power with a 7mm Ortho, still in that 2" diagonal, the moon filled up the field of view very nicely, still have some dark space around. Image stay very sharp, just slightly dim, and no false color too. I shared the view with my wife and she's more impressed than I did, she didn't expect that it could be so sharp and clear even with just so small a scope! Like before, she usually spend more time at the eyepiece than I do.

Takahashi TG-SP II Power Supply

I got a strange idea about the power supply issue on the Takahashi TG-SP II.

Since it's very small, and the tracking system is very energy efficient at 6V 130mA and so I wonder if it could be powered by the USB port. USB port can deliver 5V at 100mA norminal, and can be up to 5.25V at 500mA but it might require software handshake with the USB host controller in some case.

Electronic noise from the USB power supply is not an issue, according to a local friend, for it uses TTL logic which should accept up to 0.5V tolerance. But still, 5.25V looks a bit low.

During the discussion, it was mentioned that even a battery box with 4 pieces of AA battery (GP to be specific) can drive the mount continuously up to 20 hours, so maybe it's really worth to make sure a USB power cable?

However, since we can buy power supply box (powered by AA battery) with "USB port" interface, making such a cable might worth since in the worst case, we can fall back to use the power from our notebook.

The notebook computer will want a 12V SLA for over-night purpose, and if the TGSP-II requires a seperate 6V, it could mean extra burden, of course, if it's just 4AA batteries, it's okay.

USB power cable can be found in many places now, so the overhead is pretty small here.

Saturday, January 20, 2007

Focus test and brief eyeiece test

Cloudy today, but in order to test whether the Sky90 can reach focus with the APM Herschel Wedge or not, I still take it out to aim at terrestial targets. Herschel Wedge cuts 95% of light and it's still enough to let you see something.

With a low profile 2"->1.25" visual back other than the original Tak one, it reaches focus without problem, even still have some more rooms like 1cm or so. Therefore, it's now just a matter of clear sky and big sunspot! Let's hope.

I've also conducted a brief test of my existing eyepieces, including a 7mm J-ortho, a 13mm Nagler Type 6, a Japanese 20mm Widescan Type III, and a 20mm Tele Vue Plossl.

The Nagler first, I could detect color with both my Sky90 and the Borg 45ED on high contrast object, green and purple. It's not very obvious, but it's certainly there if you look for them. Straight lines become curved when it comes to the field edge, not a problem for night time observation. Eye-relief is very comfortable without glass, you can see all the way to the field stop, the rubber eye guard is very useful. However, it's a little bit difficult to hold the view in day light. It's the most expensive eyepiece of the batch.

The Widescan next, I could detect false color too, to a similar degree with the Nagler. Also, this eyepiece gives a warmer tone overall. Straight line become curved like the Nagler, but it's lesser, maybe due to the lower power. Eye-releif is very comfortable without glass, and you can see all the way to the field stop, the rubber eye guard is also effective. It's easy to hold the view in day light making it a fine eyepiece for solar observation. It's around 70% cost of the Nagler, but the performance is 90% at least. Image only become a little bit fuzzy near the field edge.

The Ortho follows, no false color for this eyepiece despite it's the highest power of the group. Color fidelity is excellent, straight lines remain straight all the way within the field fo view. Eye relief is a little bit short but still very useable. No rubber eye guard here, and you will need to cup your hand around to block ambient light. It's around 10% of the cost of the Nagler, the performance excels with just far smaller field of view. But it's my planet eyepiece so I have no problem with it, I still got plenty of background sky with this tiny field. Image is sharp and contrasty all the way, excellent value.

Finally we have the Tele Vue Plossl, in short, it delivers every bits of performance of the Ortho at around 40% of the cost, field of view is a bit bigger than the Ortho, the rubber eye guard is superb and serve its purpose well. Eye relief is great without eye glass. Color fidelity is excellent, very sharp and contrasty throughout the whole field of view, straight line is not distorted in any sense all the way across the field stop. I've two identical sample for this one for binoviewing, I even keep them attached in the binoviewer for storage, I seldom take them out.

In short, the cheapest eyepieces are the best performers, they just give a smaller field of view. Having said that, I love wide field eyepieces for deep sky observation, since the feeling of being out there, is unbeatable. Well made Ortho and Plossl simply deliver excellent value, clinical and scientific might be best describe them.

Friday, January 19, 2007

Sky90 and APM Herschel Wedge

Just picked up the Sky90 from my friend tonight after work, of course, one cannot test a Herschel Wedge at night, but it's good enough to have some estimation first.

I placed a 1.25" mirror diagonal into the visual back, and inserted an eyepiece which requires more in-travel than other eyepieces, to mimic the effect of a 1.25" Herschel Wedge. However, I know such combination already requires less in-travel than the Herschel Wedge, maybe due to the fact that the prism (beam-splitter) inside is big compared with a regular diagonal. Anyway, if this combination does not work, it's not going to work with a Herschel Wedge.

This combination works marginally, the focus racked near all the way inside, just less than 5mm margin. Bad.

Later, I found the original Takahashi 2"->1.25" visual back has a very long optical path and I've one which is more than 1cm shorter, so I still have hope.

Herschel Wedge is somehow troublesome here, since you cannot put a barlow ahead of it to reduce the in-travel requirement, since the barlows will be burnt before the Herschel Wedge.


A side testing of tonight is to test whether the NGF-S can be used with the Sky90. If it's just to attach, yes, it can without problem with the 2" visual back. However, it lacks the required back focus so that none of the eyepiece will come to focus with a diagonal. For webcam imaging without a diagonal, it would be fine.

Eyepiece series: Celestron SMA

Let's talk about eyepiece today, and as a starting article, I will talk about a very low cost series of eyepiece, which is the Celestron SMA.

Celestron C90 was the first telescope which I've bought for myself, binoculars not included. And the C90 has a 0.965" visual back. By the time I bought the C90, a 25mm Celestron SMA was included in the deal. Other than that, I've also acquired a Hybrid diagonal which allowed me to use both 0.965" eyepiece and 1.25" eyepiece with the C90. And I've also bought a 12mm Celestron SMA for higher power observation. Actually, I wanted something even higher power, but the dealer told me that they had no stock by then.

C90 is a f/11 scope, so it is very forgiving in terms of eyepiece requirement. Therefore, my overall impression to the SMAs are quite good indeed. The eye-relief is good too, I could easily see the whole field of view to the field stop fairly easily. At f/11, they also maintained good sharpness around the field, except to the last outer 10%.

Price at that time was considered to be cheap, but at that price, you could buy two Plossls with the price of a single SMA. So, i suppose there're little rooms for these otherwise fine eyepiece to survive in the market any more.

SMAs are Kellner, very comparable to Plossl at higher focal ratio. But in the days when Plossls are so cheap, they're no longer popular.

Thursday, January 18, 2007

Borg 45ED and remote focusing solutions

On realizing my remote solar telescope project, I need a remote focusing solution. The simplest way to control a telescope remotely via Internet, is to access your home desktop via a remote control manner, for this to work, you don't need client-server style application for all the individual operations like slewing, photograph taking, focusing, etc. Solutions like Windows remote desktop, VNC, etc can do the job very nicely. If the resolution (color depth and dimension) of the screen matches, even 10 fps with webcam capturing can be done without major issue.

Therefore, all I will need to is to buy a motorized focusing solution which can be controlled via a PC. On scanning the web, there're many solutions out there, and they have one thing in common - EXPENSIVE. Common solutions like JMI SmartFocus, Robofocus, and a couple of even more expensive options.

However, there's one big exception, it's the 1240 focusing motor from Meade. It can be controlled via Autostar through the RS-232 connection, and since it's designed for low end scopes, the Meade DS series, and so the price is less than one-fifth of the closest price alternative! Therefore, I took the plunge and ordered a 1240 focusing motor, but later I found that it's hard to mate with other focuser, and so I searched around and found a DS focuser, it's a 2" plastic rack and pinion focuser.

In order to use this focuser + focusing motor, I custom made a tube, plus related adapters to connect it to the Borg 45ED lens. After a few months of purchasing individual components, waiting custom parts to be made, and cutting the tube for proper focusing range, it's ready.

The first light is very frustrating. Like any low end stuff, any potential problems become real. Backlash, image shift, too rough focusing, vibration, etc... as long as you could think of, become real headache!

My conclusion is that, the very poor Meade DS focuser has no cure. I tried to add plastic padding to reduce the image shift, I tried to adjust the focuser tension, anything I could think of, even to add grease, nothing really help to bring it to acceptable level. They improve somehow, but not enough to be useable. Therefore, I took another plunge to order a metalic crayford focuser from China, this crayford is widely seen in many US dealers, so I suppose it's good enough.

I took the 1240 focusing motor and the Chinese Crayford to my local friend who makes adapters for me, and after one or two weeks, he told me it's extremely hard to make such a bracket. So, I gave up and got everything back home.

I searched around and found an electronic focusing solution from the UK, namely the PFocuser, the price is far more expensive than the 1240, but still around 1/2 of those solutions that I mentioned earlier. Therefore, I ordered one. It's quite nicely made, except the motor gear box is plastic, but it works too. However, the bracket which comes with it, does not fit very well, and so, backlash was still there. Accurate focus couldn't be obtained. And on mounting that bracket to the focuser, I will need to use that two tension/locking screws of the Crayford. That means, I couddn't adjust this two parameters any more. This is a big drawback.

Let me say, the Chinese Crayford is okay, the PFocuser solution is good, but they simply do not come together as 1 + 1 = 2, but instead it's less than 2, so I gave them up, too.

Searching around, I found a new product from Shoestring Astronomy, which is basically a simple controller to connect to any DC motor, you could adjust the speed of it, and it comes with ASCOM driver, and a simple GUI so that you can control the motor neatly. Best yet is the price tag, it's even cheaper than the PFocuser box! It's compatible with nearly any JMI motofocus, and thus I begin to keep an eye on astromart to look for any decent potential solutions at right price.

One morning, I found someone selling a second hand NGF-S at a very competitive price, I send an email to the seller and it's still available, and then I send paypal at once.

The JMI NGF-S arrived in great shape! Zero backlash, zero image shift, very well made! Just a little bit heavy, but it's perfectly okay! Then, I asked Shoestring Astronomy and they confirmed that the FCUSB is compatible with the NGF-S, so I send paypal really quick!

At the same time, I ordered a Borg 45ED II from a local dealer with suitable adapter to connect to the NGF-S, after calculating the back focus requirements. These individual pieces arrived in separate days, but close enough so that I can individually unit test them, and finally with an integration testing. All work as expected, and it's out of my expectation!

Borg 45ED II, 3rd reincarnation:-

Lesson learned: never buy cheap stuff, go ahead and buy the best you can afford, second hand deal could be nice, especially when it's a quality product from major brands, they are designed to last forever basically. And cheap stuff are designed to cut cost, to compromise useability for cost.

Finally, I've tried to drive the NGF-S via FCUSB, it works flawlessly, and the speed drop is not noticeable at all, and it even allows finer control than the original hand box. The original hand box is not required in this configuration, the size of the FCUSB is very similar to the JMI hand box.

Among all the solutions, I love the current combination most. The JMI NGF-S combine quality and integrated motor as a complete solution, via the FCUSB provides the capability of the much more expensive computerized solution of JMI, and yet it's much cheaper.

PFocuser is also a very decent product, provided that one can find a good mounting solution for the particle focuser that one has. However, Meade 1240 focusing motor left too much to be desired, except probably the cost.

Borg 45ED II with JMI NGF-S

JMI NGF-S with extension tube:-

Borg 45ED II combined with 7508, Intes Dovetail, and JMI NGF-S:-

After selling my Borg 45ED with custom made tube, I immediately missed it and thus I ordered a new Borg 45ED II again. The new version feature 25mm more focal length than the old version, and everything otherwise remain the same. That means 25mm more back focus, that means slightly slower focal ratio, that probably means slightly better optical quality since a slower lens is usually easier to be made good, and slightly narrower field of view.

This time, I didn't go for a custom made tube, since the last one has to be used with a large and quite heavy clamshell. This clamshell is very robust and nicely made, and it's quite expensive too, the downside is it added the weight and bulk. The clamshell is not big, but it's big when used with a 45mm scope.

So, I go for a standard tube with is Borg part #6045, it comes with a drawtube plus a 1/4" socket for mounting purpose. For such a light weight scope, such a socket is more than enough. I also ordered a 7508 which is a 2" visual back. My NGF-S is installed via a 2"->SCT adapter, the SCT side is for NGF-S and the 2" side is for the 2" visual back. 7508 features two set screws which provide very secure connection to the NGF-S.

Apart from the 1/4" socket from the Borg 45ED II, the JMI NGF-S also has one. And I found it even nicer to mount the whole thing via that socket since most of the weight now come on the NGF-S.

Since it's a non-standard combination, I did some calculations before I order the parts. On testing the focus travel, I found it matches particularly well. Basically, the whole thing worksfor such configurations:-

1. 2" refractor diagonal with 2" 40mm Pentax SMC XL

2. 1.25" refractor diagonal with all my eyepieces, from a 7mm Ortho, a 13mm Nagler Type 6, a 20mm Japanese Widescan Type III, and with any sorts of combinations with barlows like Tele Vue 2x, 3x and 5x Powermate, too

3. DMK camera with and without diagonal (extension tube needed)

4. APM 1.25" Herschel Wedge with any eyepieces listed above, the Herschel Wedge requires a lot back focus which makes it a challenge even with my Tele Vue Ranger

Focusing is a snap with this setup. The first step is to roughly focus with the Borg drawtube and then fine tune with the NGF-S.

This setup is used for wide field imaging, and solar observation, the Borg 45ED II has aperture filter thread of 52mm which matches my Solarmax 40/BF10 very well. Given its short focal length, a full disc solar shot can be done without making mosaic.

The optical quality of the Borg 45ED II is superb, no color can be seen on a remote white lamp with a 7mm Ortho plus a 5x Powermate. You could see color when it's out of focus, but it's not a major issue indeed.

For this price, Borg 45ED II is a good 3rd or 4th scope, and it truely makes up an extremely portable setup such that it will never be left behind even for overseas trip. It can be placed inside the small bag which I bought to office everyday and still have rooms for a notebook computer and all other stuff.

When used with a JMI NGF-S plus a Shoestring FCUSB controller which I've described in a separate entry in this blog, it makes the cheapest and yet high quality remote contriollable setup in the world.

You could find images taken with this setup in this blog for your reference.

Shoestring FCUSB received

This is the first non-observation log entry to this blog, and I will be adding more content when I've time. Ideas from my mind right now would be my old equipment reviews, my ideas about various equipments, observation or imaging methods, and some technical documents for beginners, and also my random ideas towards amateur astronomy. I hope you will enjoy. Back to the topic below:-

I have ordered a FCUSB controller from Shoestring Astronomy last week and it arrived today, it's well packed and the delivery has been fast. I just have to pay $6 more for the shipping to Hong Kong.

The controller is very nice in appearance, similar to a JMI hand controller. It's plastic but it serves the purpose well enough. The included USB cable is quite long.

No driver has to be installed since it's a standard HID device, the other software, ASCOM driver can be downloaded from their website.

Since I don't have any Windows PC here, nor I've my JMI NGF-S available with me, I couldn't test it right now. But I did try to plug it in my Linux box and the following was shown with dmesg:-

[17685717.880000] usb 2-1: new low speed USB device using ohci_hcd and address 2
[17685718.112000] hiddev96: USB HID v1.11 Device [Shoestring Astronomy FCUSB USB Focuser Control Adapter] on usb-0000:00:02.3-1

indicating that the hardware should be ok, I'm going to try it out tonight.

For those who don't know what is it, to make it simple, it is a USB device in which it can be used to replace your regular hand controller of your motorized focuser, it draws power from your USB port to power the DC motor of your focuser so that you don't have to provide a separate power supply. The downside is, USB can only provide 5V power and thus some higher voltage motors might work slower, like my 9V NGF-S. However, it could be a good thing as well, since your motor will run slower, and thus allow finer adjustment. I've to test to verify that.

This is a part for my remote solar telescope project, which I gave up about a month ago. However, when I came by a good dealer on a second hand JMI NGF-S, the fire burn up again!

Change of this blog

Today, I've decided to change this observation log to include any topics related to astronomy, I hope this will make my stuff more organized and useable for others as well.

Previously, they're placed some where else.

Tuesday, January 16, 2007

Failed day time observation

Usually observations do take place at night but for me, it's not a surprising thing to have a day time observation, since one of my major targets is our sun. However, this time, I ain't target at the Sun, but instead, it's another target closed to the sun by these days. Yes, it's comet Mc Naught.

I didn't bring along with me anything, no telescope, no camera, just my eyes. And it's conducted during my lunch break. The sky was covered with cloud basically, with less than 3% of pale blue sky, but I still tried.

Of course, failed as well.

A local folk successfully took an image with a telescope by using GOTO, but from his raw image, the comet is totally transparency, it only comes out from the thin cloud when the level is stretched heavily.

Of course, there's still hope. I'll aim at it again whenever there's chance.

Sunday, January 14, 2007


A very foggy day, transpareny is 1/10, seeing very bad as well. Cloud (thin and thick) floating around, too.

This is the first light of my Borg 45ED II with JMI NGF-S, remote focusing is very convenient and accurate, since I can sit in front of the LCD for everything except the T-max.

I am writing a technical document at the same time (due tomorrow morning), so I should be busy indeed for this section.

Took only a low power surface detail shot, only 200 frames available, also a low power prominence shot, similar number of frames available as well... expect noise and low contrast result.

Images below:-

Experiment was conducted with binoviewer, without 2.5x corrector, it won't come to focus, however, with 2.5x corrector, an extension tube is required. The 0.5x can be used at the same time to reduce the image scale a bit.

Some of the non-solar photographs taken:-

See how worst the observation condition is:-

My new gun, Borg 45ED II with JMI NGF-S:-

Herschel Wedge was used to check focus travel, and it reaches focus without problem, even has more room to space than with my Ranger. No sunspot today, zero chromatic abberation when in focus, can see color limb when out of focus. No bad.

On very careful observation when there's thinner cloud, I could detect a small sunspot. Cloud shows 3D structure when passing through the sun, very impressive, the view is immensive with my 80+ degree Widescan Type III 20mm, cloud could be beautiful, too.

I would say this new Borg 45ED II has a very good focus range, better than the previous one indeed.

Took the camera out again due to the detection of the small sunspot, added that 2.5x corrector with extension tube, center on it and took a shot, definitely not 930 judging from its size, no number can be found on spaceweather.com yet.

Image here:-

Saturday, January 13, 2007

Quick sneak on 13 Jan 2007

Really no time to observe, so I call it a sneak.

AR933 is out of sight already, AR930 still remain. Only had time to use SM40/BF10 with Ranger.

Two frames 1242 and 1243 stitched together:-

2x barlows also used for close up of two interesting regions, the sunspot bearing active region is AR930.



After taking four short clips, I slewed backward, remove the solar filter and insert the eyepiece to scan for the Mc Naught, failed due to poor sky and no time. Anyway.