Tuesday, March 31, 2009

Testing the Borg 45ED II with a 40mm Pentax SMC XL

It feels like crazy, but this combo is really nice! The view is very sharp and bright, extremely contrasty!

This combo gives slightly more than 8x which in terms yield 8 degrees true field of view! This field is huge, even when compared with binoculars! My Canon 10x30 IS gives *only* 6 degrees of true field!

Call me crazy, I indeed enjoy wide field viewing, I can't wait to use this combination under darker sky to scan around the summer milkyway. I expect faint fuzzies everywhere in the field of view!

Will I ever part with my Borg 45ED II? I doubt now. Maybe only a Borg 60ED which has only 25mm more focal length, that means, a very similar true field of view with added aperture!

Sunday, March 29, 2009

Extending my battery box

Recently, I'm trying to attach a focusing motor to my C5 and since the motor is a 6V model, the 9V focusing controller box from my JMI NGF-S is just giving a little bit too much power.

Therefore, I will need to make a new one. On finding a small plastic box for this project, I saw one which is pretty suitable, but it was already used for another project which is a 4.8V battery box with a USB socket.


I used it to power my TG-SP II in the field, and I also used it to charge my mobile phone, etc. Four AA rechargeables are just great for this purpose.

Having said that it's already used, but I still believe that I could also add one more purpose for it since there's still room inside.

All I would need to do is to add two SPDT switches, plus a 3.5mm mono-socket and it's done! See below:

Then, I mounted a small DC geared motor to my C5 via a pipe clamp, since it's so small, it's just very securely fixed via this simple thing. Better yet, no hole was drilled and it could be removed in seconds. I placed the excessively long wire around the visual back so in case I want them, I can release it quickly. This motor is compatible with the JMI hand controller, however, since the JMI is giving 9V but my motor is 6V native, that's a little bit faster than I wanted. However, I've conducted an experiment and I found that at the slowest setting, it's precise (slow) enough to give accurate focus.

Next is my USB battery/focuser controller box, it works without problem. Now, it's the same box but dual purpose. The 4.8V provided by four AA rechargeable is better for the driving work.

Previously, I found that my TG-SP II couldn't be used with my C5 since the scope will become shaking when focusing, and now with the motorized focuser, maybe it could be used? When weather allows, I shall check.

Saturday, March 28, 2009

Another Potential Ranger Modifications Project

1. Remove the original drawtube + helical focuser
2. Make a 48mm -> SCT male adapter
3. Attach NGF-S there
4. Attach PST etalon module there
5. BF10
6. Add an ERF in the front (77mm)

If it can reach focus, it should be quite nice. Of course, the coming Orion 100ED should be even better. But in the long run, maybe I can only keep my Ranger since it's really portable.

Friday, March 27, 2009

Orion 100ED?

This scope comes to my mind after the Borg 101ED, why? It's cheap! But another big attraction is the weight! Guess what, it's just 7-7.5lb as listed from different websites! It's about the same weight with the Borg 101ED therefore.

It's f/9, but for my application, it's even better than f/6.x for the Borg for f/9 must work with my PST etalon. f/6.x could be a little bit difficult. For wide field application, it comes with 2" focuser which is definitely better than my C5.

When comparing with the C5, the weight is so similar, so all my mounts (except that TG-SP II, but that one won't work well for the C5) are going to work. It delivers wider field of view, similar light gathering power despite lower resolution due to the smaller aperture. And I guess when I sell my C5, I got nearly enough money to cover a 2nd hand Orion 100ED, very fine for me.

It gives 2.9 degrees field of view with my Pentax 40mm SMC XL which is even close to my Ranger (3.3 degrees maximum with 1.25" focuser), and for high power, it should be even more contrasty as a refractor.

If portability is concerned, the weight alone should make it similar with my C5 but of course, it's much longer.

Minor point includes that it's front cap aperture stop is 52mm, a perfect fit with my Solarmax 40, and if I could motorize the focuser, I could even sell my Borg 45ED II.

Right now I saw a good deal, I would wait to see if there's any better deal, that also gives me time to cool down and to think twice about this idea.


I guess I will take the plunge, the shipping cost should be acceptable at around $60 USD only and my current paypal balance should be enough to pay it. I dare not to withdraw money from paypal for their exchange rate is too much discounted, so to use it for purchasing seems a smarter choice.

I will try it out with my PST etalon, as well as with my Herschel wedge. If it works out nicely, I will sell my C5 and that could give me back at least 2/3 the amount which I have paid. If it does not work out well, it makes little harm to re-sell it locally.

Actually, I suspect that it will work far better, as there's no secondary mirror to give that internal reflection! And the possibility to be able to use it with my Herschel wedge is really attractive. The wide field capability due to the shorter focal length (900mm vs. 1250) and the 2" focuser vs. the 1.5" rear openning is also great!

At the time being, I will still try to motorize the focuser of my C5. In case it works, maybe I can ask for a little bit more money when selling it.


Payment just sent, my paypal account has more balance than to cover it, the expected time for delivery is less than 10 days. Really longing for the new member.

I'm now worrying if it's too long that it would be hard to use in an indoor setting? Anyway, got to check.

Monday, March 23, 2009

The Ranger Transformation Project: From the beginning to the end

It's time to summarize everything. First of all, please make sure that you know what you're doing before you do anything to your Ranger. The Ranger is a discontinued legend, so take your own risk and I take no responsibility about the accuracy of this project because there is a chance that not all Rangers are created exactly the same. And I believe, no two Rangers are identical.

First of all, I slide the balance dovetail to the focuser end, and then I can remove that small screw which acts as a stopping pin.

After removing that pin, you can remove the dovetail easily. Be sure not to lost any screws in the process. There're some plastic tip in the set screws and so the metalic part will not be scratched. After removing the dovetail, two more screws will be seen.

One of them is to hide the pin which guide the drawtube, the other one is to fix that dovetail saddle on the OTA. If you have done everything correctly, you can remove the whole draw tube slowly.

One I have removed that draw tube, I found it pretty long. On placing it side by side with my NGF-S, I immediately hope that I can use that NGF-S to replace that helical, and to custom made another draw tube (48mm outer diameter) to replace the original draw tube, by then you actually gives 2" capability (close to 2" actually) to the Ranger!

However, before I proceed, it's actually nice to check if it works or not by doing some feasibility studies:

As you can see, I placed that NGF-S immediately behind the opening for the drawtube, and then I inserted my 2" mirror diagonal and my 2" Pentax SMC XL 40mm there. I view through the eyepiece, and it's quite good... However, on adjusting the NGF-S through the whole range, it won't focus. Worst yet, it's on inner end, i.e. I cannot focus even if I'm using the shortest setting of the NGF-S... i.e. insufficient in-travel! If it's out-travel, I can always use an extension tube, or to make a longer drawtube, but now, there's no chance. To make it even worse emotionally, I believe it took only around 1cm or even less!!!

With 1.25" diagonal, it will work, but then it makes less sense to do so. It just gives motorized focusing, but nothing else. Frankly, I can cut the Ranger OTA a little bit on the drawtube side, but I hate to do anything intrusive modification since the Ranger is a discontinued legend, I don't want to kill it altogether.

File closed.

Sunday, March 22, 2009

Transforming Ranger Project

I tested the focusing travel by conducting some experiments:

1. 2" diagonal + 2" eyepiece: coudn't reach focus, still need around 1cm of in-travel, a bad news indeed!!!

2. 1.25" diagonal: it works basically... it reaches focus with my 20mm widescan, with and without 2x barlows; it reaches focus with my 13mm Nagler, so basically, it's a good sign. But there is not much room remain... maybe it won't work with my BF10? I got to test!

Since (1) failed, the motivation to continue the project is much reduced. Of course, if (2) is really do-able, the incentive will be to sell the Borg 45ED II which further consolidates my equipment line up, which is a good thing definitely. However, since the focus travel is around just-make, so whether it will work or not, is pending further testing. Secondly, a reducer couldn't be used most probably, that makes full disc in one shot impossible.

So, not much incentive remains. Since the NGF-S is already very "low profile" and thus, any other focuser is not going to work most probably. Give up?

Saturday, March 21, 2009

Making my Ranger a motorized "Pronto"?

Tonight, I have a very strange idea.

Actually, the Ranger is inside my closet and I will never part with it due to emotional reason. It's my first serious scope, and I just have so much great memories with it. However, it's 1.25" focuser is limiting its function... It couldn't accomodate a binoviewer without a corrector as well. Wide field scanning is still great with my 20mm Widescan Type III, it gives more than 3 degrees of true field, but more is definitely better. Let say if it has a 2" focuser, I could use my Pentax SMC XL 40mm which will give more than 5 degrees!!!

Another point that I'm not using it any longer is that, it lacks a motorized focuser. I found motorized focusing very convenient when solar imaging is concerned. That's part of the reason why I'm using my Borg 45ED II more actively now.

So I guess if I could use my Ranger with a motorized 2" focuser, it would be great!

I pulled my Ranger out tonight, to see if I could remove the focuser, again, it's hard... I guess it takes some tricks to do so. Then I looked at the draw tube, it's close to 2"... 48mm to be exact, so if I could remove the draw tube, I guess I could attach my NGF-S there?

I turned my Ranger upside down, I saw a slot which governs the drawtube travel, so I know that there must be a pin there guiding the motion, and at the same time, to stop it from getting out completely! So, I know that I could remove the drawtube easily as long as I could remove that pin! After some work, I got it done!

Therefore, now the next step is to make another draw tube for it... And at the end of this draw tube, I shall make an adapter to connect to the NGF-S! That would:

1. enable the Ranger to use 2" eyepiece!
2. enable the Ranger to do solar imaging again with a motorized focuser!

Before doing that, I will need to check the focuser travel, to see how long a draw tube that I should make. Frankly, I could make it exactly like the original draw tube with the helical focuser, but then I know I want to make it slightly shorter to save some weight. A longer draw tube should cause vignetting.

I shall also see if I could accomodate a binoviewer without corrector. And at the same time, I would want to be able to use a reducer in this setup, and if possible, to bring down the focal length to around that of my Borg 45ED II so that I could do full disc solar imaging as easy as before.

A very nice project really!

The design of the draw-tube with NGF-S should look like this:


However, that M57P0.75 side should become 48mm (outer diameter) instead, and how long it should be is pending design.

I'm very excited about this idea!!! If it's done, I could sell my Borg 45ED II and my equipments could be further consolidated, better yet, it saves my Ranger and gives it a new life!

Test run of the autoguiding motors and electronics

I wired the electronics and the motors together and give it a shot!

Everything work as expected. Since the "enables" will only disable when they're logically low, and therefore, I could skip them at the time being to make the wires less messy.

So right now, I just need to connect the electronics to that ST-4 socket, and the next step would be to make a ST-4 compatible hand controller to try out motorized hand guiding. If everything work, all I need would be a ST-4 compatible guiding interface (GPUSB, etc) or a guiding camera which could produce ST-4 signals.

Friday, March 20, 2009

Further improving my C5/PST setup

Now I'm pretty satisfied with my C5/PST setup, since the internal reflection issue has been resolved, the contrast is superb now! The histogram is fully filled now unlike before!

So, what I'm missing now is the motorized focusing! I can always use the NGF-S from my Borg 45ED II setup, however, adding the PST etalon and the BF10, the C5 will become very much back heavy...

Right now I have two small DC geared motor around, and I guess with suitable mounting hardware, I can use them for motorized focusing! I shall try to do it asap.

20090320 Sun

Great seeing, I would rate it 6/10, it's rare for day time! Transparency usually suffered under this kind of seeing, it's like 2-3/10. Telescope is my Celestron C5, with PST etalon and my Cheapy-ERF with BF10. Camera is my DMK 31AF03, tracked on my Meade LXD55, everything indoor from an open window as usual.

Solar activity remains low, but larger aperture really helps to bring out something. Our star is always dynamic, it's just a matter of aperture and focal length if it's not the case. During solar minimum, aperture fever gets worser... I still remember several years ago, I announced that 40mm is more than enough for most situation - you know what, longer focal length is useless, unless you're willing to do mosaic every time you took any active regions at those time!

Back to the reality, bigger aperture is the only way out these days.

1622 (GMT+8):-

1626 (GMT+8), somewhere in the middle of the disc:-

1629 (GMT+8), a corner:-

1630 (GMT+8), another corner:-
Processing this kind of images (under good seeing) are very easy, just stack them, slide the wavelet level one to around 60, made false color, done!

Thursday, March 19, 2009

20090319 Sun

Again using my C5/PST setup, cloudy today so that I've to use autoexposure to track the cloud's thickness variation. Seeing poor at 2/10, transparency also 1/10. Low activity today.

1555 (GMT+8), this one is very dim as you could see from this image, I've overexposed many things (blacken) in order to bring this one out. Due to the poor transparency, noise is getting high:-

1603 (GMT+8), the etalon is performing very well now, the amount of surface detail and the uniformity both improved, even a small active region like this one shows up very nicely, this shot is taken with autoexposure so that the software changes it exposure to adapt to the varying thickness cloud. Slightly down sized to hide the noise:-

Wednesday, March 18, 2009

Getting more field of view from a Celestron C5

Last time I went stargazing, I really wanted more true field of view. I used to play with my C8 with a 40mm SMC XL before, which yields around 1.3 degrees true field. That session, I used my C5 with a 20mm Widescan Type III, that gives around 1.3 degrees true field as well, but the view provided by the C5 is just not as attractive.

To get wider field of view, we can either use a reducer or a bigger diagonal. People always said the small baffle of the C5 will prevent you from using a 2" diagonal, but who knows how worst could the vignetting get? So, why not give a try?

First up is a Hirsch f/6.3 reducer. I used the 1.25" visual back and a 1.25" Tele Vue diagonal for testing, my 20mm Widescan Type III is used... Yes, the true field of view is just much wider than the 20mm alone without the reducer. The focus difference with/without the reducer is quite a lot, and it's not so convenient in the field especially you will want to remove the reducer for higher power.

Second up is a 2" diagonal. I used a 2" visual back together with a generic 2" diagonal for testing, my 40mm Pentax SMC XL is used. The true field is indeed much wider than the 20mm alone without the reducer. And my impression is that, it yields even more true field than the above setup! The image is also brighter since the exit pupil is bigger for this one. To use higher power, we just need a higher power eyepiece! This is just more convenient in the field!

Having said that, the 2" visual back plus the diagonal is making the C5 even more back heavy... and it seems funny to use those large accessories and eyepiece with such a small telescope.

My verdict? Visually, I would prefer the 2" setup based on my Pentax SMC XL 40mm, but mechanically, the reducer based setup seems a little bit better.

But since I'm primarily a visual observer, I would say I prefer the 2" setup more!


Remarks: I'm now more inclined to keep my C5 after tuning that PST etalon, the result is just fantastic given its low price. Also, my desire to go for a Lunt's CaK diminished after knowing that they raised their price recently. Given the chance about going for a Borg 101ED is further reduced along with that CaK, I guess that I shall maximize my C5 instead of buying/selling anything at the time being.

20090318 Sun (C5/PST)

Against my usual practice, I took out my C5/PST based setup without going through my Borg 45ED II/Solarmax 40 setup. Maybe it's due to the fact that I've watched some images from a 100mm Lunt's?

Seeing is 2-4/10, transparency is 3/10. Cheapy-ERF/Celestron C5/PST/BF10, DMK 31AF03, Meade LXD55.

1611 (GMT+8):-

1618 (GMT+8):-

1619 (GMT+8):-

1622 (GMT+8):-

And then followed by shots taken with a Tele Vue 2x barlows:

1625 (GMT+8):-

1626 (GMT+8):-


I spent a lot of time tuning my PST etalon today, I even disassembled one of the afocal lens in the hope trying to see how I can fix the internal reflection issue. I'm a bit surprised to see that those afocal lenses are singlets... Anyway, they work... edge blacken, not bad. I removed that tuning ring so that I can have direct access to the rotator inside, that gives a wider range of adjustment. I found a spot in which the internal reflection is gone, and the amount of detail (bandwidth?) is still acceptable. Uneven illumination is still there, but it's not as serious as before.

The images above are taken before the tuning, and the images below are taken after.


1644 (GMT+8):-

1646 (GMT+8):-

1650 (GMT+8), after tuning the etalon, the field is uniform enough:-

Encouraging results.

Tuesday, March 17, 2009

20090317 Sun

Telescope: Borg 45ED II
Camera: The Imaging Source DMK 31AF03.AS
Mount: Meade LXD55
Filter: Coronado Solarmax 40 with BF10

Seeing 5/10, transparency 3/10, low activity again but there's a dim and medium sized prominence. If the transparency was higher, I would have pulled out my C5/PST based setup to get a closeup.

1402 (GMT+8):-

1403 (GMT+8):-

1405 (GMT+8), with 2x Tele Vue barlows:-

Monday, March 16, 2009

20090316 Sun

The sky is cloudy basically today, but we have some bigger cloud gap. Those small active regions were gone essentially, and solar activity is very low. Seeing 4/10, transparency 3/10.

1443 (GMT+8):-

1444 (GMT+8):-

Telescope: Borg 45ED II
Camera: The Imaging Source DMK 31AF03.AS
Mount: Meade LXD55
Filter: Coronado Solarmax 40 with BF10

Sunday, March 15, 2009

20090315 Sun

It's clear today, see gets better like 3/10, transparency is 5/10. Few surface activity, not very much prominence activities, too.

1527 (GMT+8), we see two or three ephemeral regions:-

1528 (GMT+8), poor seeing, so no detail could be seen:-

Saturday, March 14, 2009

20090314 Sun

It's totally clear today, the temperature dropped from 25+ degrees to 13 degrees this morning. The strong wind cleared up the sky! Without imaging the sun for one or two weeks, the sun has changed its location relative to my window, so the angle is getting harder now. I'm now waiting for it to come into my view. Later, I will need a longer extension plate to catch the sun from inside my home like those past summers.


Seeing extremely bad at 0.1/10, I could see a zigzag pattern around the whole solar disc even at low power (16x), transparency 6/10.

Borg 45ED II, Solarmax 40 with BF10, DMK 31AF03 tracked by a LXD55:-

1313 (GMT+8):-

1314 (GMT+8):-

I also got some visual view with my 20mm widescan type III, several rather big prominences were around, but due to the poor seeing, I didn't do any close up. The biggest one is faint, but it shows very fine detail.

Friday, March 13, 2009

TG-SP II Project Continues...

When it got started, you will move on. Last night and this morning, I spent some more time to do more work on this project, here are the results:

In short, the motors are mounted on the plastic board. The holes that I drilled yesterday were enlarged, since I need to put in the mounting screws. There are two mounting screws for each motors. The holes for the mounting screws were made by using a low power soldering iron.

Inline shaft couplers were attached to the motors.

So, it's ready for some basic testing. I just applied 6V and 12V DC to the motors, trying to see if the mount moves correctly:

Yes, they did! They slew slowly, good enough for guiding at 6V. They slew faster at 12V, but it's still a bit too slow for general slewing, but then it's not the main purpose of this project.

I have continue the test for several minutes, and then reverse the direction of the voltage and it works flawlessly as expected.

However, there is a problem. The plastic board is too thin, and the hole is not perfectly aligned with the control knobs of the mount, so I found that the board would flex periodically slowly when the drive continue to work.

That's fine for manual motorized guiding, but for autoguiding, would the software would be cheated? I think no since the adjustment is always guided with a CCD, and therefore, the flexture could be absorbed automatically. It will just affect how fast the motors could response to any tracking or polar alignment errors.

However, that periodic movement would greatly affect the amount of backlash... And actually, it's exactly a huge source of backlash.

So, could the project continue? Yes! At least the current setup which I'm now making could be considered as a prototype for the proof of concepts!

If it works, I shall migrate everything to a metal board, with better mounting. Better mounting should probably required, since the motors are now fixed by the control knobs of the mount only.

Let's see how it works out eventually.

Next steps:

1. Attach the driving electronic (a Solarbotics board)
2. Design the control box with a variable resistor to control the speed of slewing

But since I don't have any autoguiding interface, autoguiding will be the next step... but then since the Solarbotics board should accept autoguiding signals without problem, and therefore, the autoguiding part should be just some simple soldering work.

That is, if motorized manual guiding works, autoguiding will work with minimal amount of work!

Thursday, March 12, 2009

Cloudy day exercise

I've been busy with so much stuff and got no time to follow up my Takahashi TG-SP II autoguiding project. The last progress was that I bought a thin plastic board for mounting the motors, I need to drill holes to mount the motors there.

Today, I got a few minutes to drill those holes. I didn't get a drill, and I planned to borrow one... but since it's just a sudden short free moment, I didn't go to borrow one, instead, I use a hot screw driver to drill slowly... that has a good advantage of being able to adjust gradually! I made a very small hole at first, try to match if the location is fine, make it bigger in the next iteration and during the enlargement step, I could adjust the location slightly every time.

It's a perfect fit eventually!

I will need to drill holes to fit in the mounting screws later, but I don't know when I will have time again.

Tuesday, March 10, 2009

20090310 Sun

We got no sun for so long, today, I saw a white disc within the cloud, so I took my DSLR to take a shot! Hopefully, we will have a clear sky really soon.

Monday, March 09, 2009

Using C mount lens on DSLR?

People always said that it's impossible due to the difference in back focus. While it's true in the general sense, but then if you limit your usage, it might work.

In the general sense, C mount lenses have a much smaller image circle, and thus, we should expect heavy vignetting even if it comes into focus. Therefore, we just shouldn't expect it to work well in general.

Since C mount lenses have much shorter back focus than regular DSLR lenses, that means C mount lenese have to be placed very close (too close!) to the DSLR sensor in order to reach focus at infinity. However, if you don't mind about it, you can always use it as a macro lens. To demonstrate this concept, for a regular DSLR lens to use as a macro lens, you need an extension tube. For a C mount lens, since you cannot put it close enough to the imaging sensor, that means you are forced to have something like an extension tube... by then, macro photography became the default setting.

Virtually all DSLR has a corresponding T-ring which is M42 threaded, and the C mount has a 1 inch thread, so if you can find such a step down ring, macro photography with C mount lenses should be possible.

Tuesday, March 03, 2009

Upgrading with minimal amount of money?

Suddenly, I want a Borg 101ED again. But I don't want to spend much to buy a new scope, what should I do?

To put it simple, by selling and buying, i.e. re-organizations.

First of all, my Borg 45ED II is not a must-have for me, however, I truely love its motorized focuser for solar imaging, the new setup should do its current job. For motorized focusing, the NGF-S should be able to adapt to the Borg 101ED without much problem. Therefore, the only issue is that, if a strong focal reducer could make the Borg 101ED focus and at the same time, allow the solar disc to fit into the field of view of my DMK 31AF03? Frankly, it's not very likely possible without shortening the tube. However, a shortened tube could be nice for binoviewing, so it might worth the effort?

Secondly, my C5 could be replaced by the Borg 101ED, and better yet, it allows wider field of view for visual observation. Finally, the Borg is lighter as well so that I can sell my LXD55 which is not required any more.

Shall I execute this plan? I think the answer is probably yes. However, shall I execute this plan now? The answer is probably no, since I could always wait for a good second hand deal to come up first.