The tribulations of a very experienced astrophotographer

[EricB]

Hi there!

A few weeks ago, I got myself a 10" Sky Watcher dobsonian flex goto scope with the view of trying my hand at lunar and planetary astrophotography. In a previous thread, I asked about entry-level ccd cameras (http://www.iceinspace.com.au/forum/showthread.php?t=86413) and took up Poita's generous offer to lend me his Imaging Source DMK21 to "try before I buy" (thanks Poita!).

Upon receiving the camera, I installed ICapture on my laptop (the software comes with the camera) and downloaded Registax 6. So far so good.

I was told by the astronomy dealer I had planned to buy the camera from that the problem with the Sky Watcher focuser I had on my scope was that it didn't have enough travel to reach focus with the Imagining Source cameras (not enough "rack in", to be precise). Luckily, my scope being collapsible, I could shorten the length of the scope by not extended it fully. I eagerly awaited for night fall with the intention of testing the DMK on Jupiter which was still visible in early evening.

The first night was a disaster. I hooked up the DMK in the focuser. I could find Jupiter in the viewfinder, but could see it on the computer screen (I was operating the scope manually). When I eventually caught it and kept it on screen for a few seconds, all I could see was a huge disc with swirls and the shadows of the secondary's arms... By the time I had my hand on the focuser, the disc was gone! I tried again and again only to managed to focus to a smaller white fuzzy disc. I was demoralised.

The next day (following Poita's advice), I tested the camera during the day. I shorten the scope by 15mm, pointed the scope to a far tree and managed to get the camera in focus. While I was at it, I took a few snapshots and a couple videos of gumtree leaves to practise on ICapure. Night time came, the scope was set up (extended minus 15mn). The viewfinder was perfectly aligned. This time, I had the tracking enabled. I aimed a Jupiter, locked it on the computer screen, focused... All I got was a nice white disc. I tried on stars and could only see the brightest ones on the screen and couldn't quite focus on them.

After a rainy interlude of a couple of days, I took the camera out one last time (I didn't want to abuse Poita's kindness by keeping the camera too long). The scope was set up at minus 25 mm. It was still daylight. The sky was overcast, it was windy but there was a 15 mn break during which I could catch the Moon, low in the western sky. As it was a much easier target than Jupiter, I caught it quickly on screen and managed to focus on it. The camera focus wasn't perfect, far from it, but the focuser could travel either way of the focus point. I knew then that the length of the scope was right for the camera. I recorded 3 AVI videos of about 10/15 seconds each with the Moon coming in and out of high clouds and the scope shaking in the win.

I have processed 2 of the AVis which show the moon drifting through the visual field. I ended up trimming each video to 3 seconds of the most stable images and stack about 300 frames on Registax. Here are the two resulting pictures. Bearing in mind the very bad seeing conditions, my total inexperience in imaging, the ad hoc set up of the scope, I am rather pleased with the photos (see attached).

So what do I take out of all this?

Well, I can no longer take for granted that imaging is just a matter of popping a camera in the focuser and pressing on the Record button. I now foresee that it's much more than that. I am going to have to do my homework!

I also know that the scope as to be perfectly set up in order to locate and track the target object through ICapture.

I now sense that focusing the camera is a very big issue. I was only able to achieve rough focus. I need to get myself one of these focusing masks to improve focus.

I have worked out that my SW dobs scope isn't ideal to be used with an Imaging Source camera. But shortening the scope by 1 inch is a way to get around the issue (but with that configuration, I no longer get my EPs in focus, there is some fine tuning to be done to get both the camera and the EPs in focus at the same time).

It's also important to ask someone when you are stuck. I would have gone nowhere without Poita's help.

No matter how frustrating this challenge has been, I got a result, as imperfect it may be, and want to go further. Soon, I will get my own camera!

Any advice is welcomed.

Cheers,

Eric

PS Sorry for the long message.

[multiweb]

Good on you Eric, practice makes perfect. What you are saying sounds very familiar, almost like Déjà vu and yes you are correct: focus is critical and often overlooked by beginners. Unfortunately good focus will then show other aberrations, such as coma, tilt, field rotation, bad seeing, dew, etc... it s a long road so keep doing what you're doing and enjoy the journey. The important thing is to be happy with your shots and what you get out of your gear. :thumbsup:

[jjjnettie]

Thank you very much for your story. I hope to be doing exactly the same thing next week. It's good to know that I can shorten the extension support struts to gain focus.

[EricB]

Thanks. It has really been trial and error. It not over yet, but I knowhave an idea of what to expect.

Once I have the camera, I will probably permanently set up the scope short for photography, and may use a short an extension tube to focus the aeps if required. Jjjnetie, let us know how you go with your own set up.

Cheers,

Eric

[JB80]

Do you think I would have the same issues with my Skywatcher 150PL?
I am close to pulling the trigger on a DMK41 but now reading this I don't know.

[EricB]

Hi Jarrod,

I don't know your model, other members may have an idea. What triggered the whole issue is that I asked the dealer to tell me if the DBK 21 was fine to used with my scope (eg whether it needed an adapter). I suggest you ask your dealer.

Cheers,

Eric

[Poita]

Eric, have a go with Autostakkert as well with the data you gathered and see how you go.
http://www.autostakkert.com/

[Poita]

The camera arrived back today. Thanks Eric!

[ballaratdragons]

Hi Eric.

Yes, my advice is give up now!

Unless you have a bottomless bank account :lol:

[ZeroID]

Hi Eric, congrats on your successful capture. I have still yet to get my own setup working but the journey is proving immensely interesting and educational. Close but no prize so far.
I used my Bahtinov mask for the first time the other night and suddenly understood just how it worked and how useful it was going to be.
Keep the updates coming, we aspiring astrophotogs need all the encouragement we can get to stick with it.
A limitless credit card helps too btw, I seem to have lost mine. :rolleyes:

[EricB]

Hi there! I have just realised the error in the title of the thread. Of course I am not very experienced! I am very INexperienced :D.

Peter, I am glad the camera got to you quickly safe and sound. I am already missing it.

Thank you ZeroID for the encouragements. If I can help newbies like me avoid the mistakes I have made, great!

Ballaratdragons, it was astronomy or that nice red convertible middle-aged men sometimes lust on. My wife's happy with astronomy ;)

On a more serious note, reading an article on modding webcams in Projects and Articles section gave me an idea yesterday. I had a old disused Logitec 3000 and decided to have a go at it. I followed David Childs' instructions to the letter. And even if it wasn't the same model, I manages to open the case,take the lens off, close the case and stick a 1.25" plastic tube to the it (a film container). It took me 15 mn to do the job. The tube fits the 1.25" focuser adaptor perfectly. The problem was that neither ICapture nor Firecapture would recognise the webcam. At that point, I thought "that's it, I have wasted my time". Then by chance I downloaded a nice little program call Sharpcap, which luckily did recognise the camera. It first I couldn't focus, but once I have shorted the scope by one inch (like for Peter's DMK), I achieved focus. The Moon was out (very bright though, about 80%) and, to my amazement, I could get a picture! I took about 10 videos of 10 to 20 seconds each, trying to keep my lunar points of references steady on screen. I have processed one of them. The result is attached. Not great but better than I expected from an old webcam that I was going to throw away!

I think beside the poor quality of the camera, I have no idea about how to use Registax. But with those AVIs, I can experiment until I understand how it works.

Cheers,

Eric

[robz]

EricB!...................that shot of the moon with an old webcam is incredible.:eyepop::thumbsup:
I have just picked up a brand new Logitech C600 which has a native 2MP chip for $27.00!!!!!...............this will be dismantled and built in to a cast aluminium case with 2 inch nose peice. Will be interesting to see how it performs as a planetary imager....???????

Rob.

[Poita]

Great work!
You now effectively have something on a par with a celestron Neximage, and you will be surprised what you can eke out of it.
Plus, as you said, it is a great way to learn registax/nebulosity/autostakkert etc.
Well done!

[EricB]

Thanks for you encouragements Robert and Peter. I have another webcam, a more recent HD one. I might give that one a try too. But I really have to get on top of registax. I have downloaded Autostakkert but haven't been able to use it.

Cheers,

Eric

[midnight]

Eric you must have been very happy with that moon image!!

Good luck on your quest. And for me, it took me several weeks to work out why my 1st webcam images were terrible. The gain was too high so all I was getting was a white Saturn with no detail.

Control Gain and Exposure on your camera. Normally it's somewhere in "properties" in your capture program.

Use Registax 6 and start with its default settings (ie selecting bugger all) and give that a go.

Good luck!!!

Darrin...

[EricB]

Thanks Darrin, I had the gain and exposure to minimum otherwise the picture would have been completely washed out.

[Poita]

Are those doubled up craters a result of the stacking, or is there some reflection somewhere in your chain?

[jenchris]

EricB - great result - did you realise you've got a huge ghost on there - every crater is duplicated up and left!!

[EricB]

Yes, it's not great. I wonder whether it come for the alignment in Registax.

By the way I have tried to process this AVI in Autostakkert, but I don't know where the final stacked picture is saved. I can find the log of the processing session but not the picture. Could someone tell me where it is?

Is there a save in folder option in Autostakkert?

Thanks,

Eric

[asimov]

It'll be in a newly created folder called *example only!* 'AS_p50_multi' or something similar, Eric wherever your original AVI is. Confusing at first. I used to move my AVI to a newly created folder on my desktop, that way I knew where to look..:)

[Poita]

What Asi said :D

You can always use windows search to find your file, then right click on it and choose 'open file location' and it will take you to the folder.

[EricB]

Thanks guys, but I still can't find it. It's not in the folder where the original AVI is. There s an AS P50 multi folder with photos processed last week ( which I could find...).

Autostakkert doesn't have a wavelets function is that right?

Cheers,

Eric

[EricB]

I have redone the faulty lunar shot. I can't believe I didn't spot the doubling in the first place! Here it is with two different gamma treatments (Registax + Photofiltre). No doubling this time.

Cheers,

Eric

[Poita]

Weirdly, mine once ended up saving them onto a USB stick!

[Poita]

Ah, much better!
A few blown out highlights, but very nice overall.
I tend to underexpose a bit on the moon if I can, the detail is usually still there and can be stretched out, but if overexposed it is all gone.

Nice job with the webcam, you will be able to do some real work whilst you save up for the DBK21.

[EricB]

Thanks Peter.

I had a go at Jupiter yesterday very disappointing compared to the moon shots. With exposure to minimum, it was still a white disc with faint stripes. Processing didn't help. Hopefully I will get the DBK soon.

Cheers,

Eric

[jenchris]

+1 Poita - underexposed is easier to correct.

[EricB]

Hi there,

I have reprocessed the image attached to my first post (it's flipped though).

AVIstacker+Photophiltre+Paint. I seem to get pretty good results with AVIstacker compared with Registax, or is it that I am getting better at it?

Too dark? Please let me know how I can improve it.

Cheers,

Eric

The weather has been pretty ordinary in Adelaide. I haven't been able to take the scope out for days!

[EricB]

Here is a photo of Copernicus taken yesterday with my modified low def. Logitec webcam. It's processed from a short AVI of 75 frames only in AVIstack, on manual mode but using most of the 'factory' settings. I have tweaked the wavelets a tiny bit and adjusted the levels in GIMP.

My best astro picture so far, I think.

Cheers,

Eric

[Astroman]

Arghhh we have created another monster :D Seriously your efforts are very well done Eric, you are showing great promise and your moon images are excellent. Keep at it, and better buy more storage space for your computer...

[EricB]

Thank for the encouragement, Andrew. I now store my AVis and photos on a dedicated external drive.

Cheers,

Eric

[Poita]

Wow, that is tidy, not too overprocessed which a lot of moon shots tend to be.

Great work from the webcam, I'm blown away.

[Shark Bait]

That is a cracker Eric. Keep them coming.

[EricB]

Thanks Peter and Stu for your good words. I have kept the processing to a minimum to avoid harsh contrasts. I would be happier with a crisper picture though, but I don't think the webcam is able to deliver that. I would have to move on to a better camera.

At this stage I am considering the DBK 21AU618.AS or the DBK 31AU03.AS (still saving!). In your opinion, is there a significant difference between the two?

Cheers,

Eric

Edit: for a great picture of Copernicus look here: http://moonscience.yolasite.com/wac_mosaics.php . Simply stunning!

[EricB]

Hi everyone!

Well, while I wait for clear skies above Adelaide and for the new CCD camera I have on order (3/4 weeks wait :(), I have reimaged some of my lunar shots taken with my old webcam.

After months of indecision, I have finally bitten the bullet and have gone for the DMK41. I will mostly image the moon with it but will occasionally use it for planets. Perhaps later, I will get the DMK21 or a DSLR.

I have reprocessed this shots in Registax 6 and touch them up very slightly in GIMP (levels and and a tiny bit of unsharp mask). They look a bit crisper than the ones I posted before. I have experimented a lot in Registax and I am slowly getting the hang of it. I can't wait to get new AVIs to process...

Cheers,

Eric

[2stroke]

Why on earth would you use a DMK41 for imaging the moon? A DSLR would wipe the floor clean against it, for the money you spent you could have got a nice secondhand nikon d3100 or cannon 550D or new 1100d. It will be great for planets but its going blow for high res images of the moon, its the wrong tool for that job IMO :(

[EricB]

Thank you for your input Jay.

I have based my choice on research I have done on the web and advice I have received from the place I have bought the camerafrom.

There are also a lot of positive comments about the DMK41 in relation to moon imaging, due to its capacity to capture large areas. On IIC there is a favourable review of the camera by Mike at http://www.iceinspace.com.au/93-527-0-0-1-0.html and some good photos taken with the DMK 41 at http://www.robertreeves.com/Moon20Aug2011.htm and http://avertedimagination.com/img_pages/schiller_100407.html

I will know in a few weeks if I have made the wrong choice...

Cheers,

Eric

[2stroke]

Hope it goes well for you Eric, as soon as you get the chance try a DSLR and see what you think though. Hmm i forgot that you will probably be stacking close up creators and high mag work so it should pay off there with air turbulence :)

[EricB]

I must say, I haven't really looked at DSLRs, so I can't really compare. But from what I have seen, the DMK41 should do a decent job on the moon. Hopefully substantially better that my current mod webcam.

[Poita]

It works great for the moon, you get to stack a lot more images than you do with the DSLR and you get a greater level of magnification because of the chip size. If you want really high res images mosaics are easy, and it makes a cracking solar imager as well.

[EricB]

Thanks Peter. I have thinking about going solar at some stage!

[EricB]

The DMK41 has arrived after 2 months waiting (it was out of stock).

I only managed to use it once, 3 days ago, most as a test than for a serious imaging session, and here is the result of my first attempt on the Moon in low resolution (Tycho is in the bottom right hand corner).

The image was captured just ahead of some bad weather. The seeing was very bad (possibly the worst I have experienced so far), but I had to have a go.;) The Moon was coming in an out of cloud before dusk, between the branches of a large tree. Not ideal.

The scope wasn't aligned (it was still daylight) and I used the manual tracking. The AVI was only 100 frames. The DMK was used through ShapCap as I didn't have time to upload IC Capture which came with the camera.

The AVI was processed in Registrax 6.

I must say, I am a bit disappointed with the resulting picture (don't tell 2stroke!). I find it grainy, flat and lacking definition, especially compared with those taken with my old Microsoft VX3000 webcam. I will have to wait for better seeing conditions to try it properly. I like the subtle tomes though which I didn't quite get with the webcam.

I also noticed that I had dark spots on the AVI. It seems that it's dust particles on the chip cover. Can it be cleaned with a cotton bud (I don't have any air blower)?

Let me know what you think and how I could improve future AVIs.

Cheers,

Eric

[Poita]

The graininess is as a result of the seeing. Turn the gain down to zero for the next lunar session and you will be much happier with the results.

[2stroke]

Use air in a can designed for cameras/electronics aka air duster Eric. Hold the can upright and give is a quick burst to clear nozzle of any liquid propellant, then keep it upright a quick burst about 150mm away from the sensor. If the dust still sticks use a sensor swab or get a sensor brush, i use make-up applicators which are of very soft foam for oils and stubberen dust and lightly sweep it off. This method maybe wrong but lol i don't own a $7k camera, and i have never left any scratches in any of my sensors. If you google dslr lens/sensor cleaning you will find a ton of info and methods.

With your camera and low res how about making a mosaic out of highly magnified images. Turning the gain down will help out with noise and you can increase exposure to compensate. Lol i'am far from being an expert and would say of novice if that :) 1 more thing is to check out your codec and that your using a lossless, this will give you the best image possible. If your using a compression codec then you will pull higher fps but the images are like jpeg vs raw/tiff. If the seeing is bad by that i mean air turbulence drop back the res and crack the FPS up, it will give you a chance to get some clear shoots in the avi though more gain maybe needed.
Lol things never go right first time around haha, gl to your next session and do some googling on your dmk41 to get others tips and wisdom.

[EricB]

Thanks Peter and Jay for the tips.

Jay, as far as codec and video format are concerned, I only have Y800 and AVI available. So I don't have any other option.

Cheers,

Eric