Heath Robinson ...

[ZeroID (Brent)]

Being a long time serious photographer eventually I knew I'd be wanting to shoot some AstroPix. Tried to so some short exposure (6 secs) from a tripod but star trails were obvious. So I've been trying to build a 'Barn door' or equivalent to mount my KM 7D on. Picked up a $15.00 240v 1/10th RPM motor from local surplus bits store and pulled a couple of 1:1 nylon gears off an old Photocopier toner reclaim system. Lathed up a bearing or two to fit the gears to the worm drive on the 4.5" shaky EQM mount and got it all to work. Added a side plate to fit the camera on. Used Google Earth to get an accurate Nth Sth Alignment on a pathway in the backyard (20 degrees West offset exactly) and ran some timing tests to see how it went. Stunning clear night conveniently came along and I took some pix.

Here's the setup and here is a wide feild Orions Sword stacked over 10 frames, 4 secs, f5.6 160mm lens, 800 ISO. Lots more to do and I don't think I've quite got the hang of Registax but there is colour and shape.
The thing that impresses me though is the tracking ! Stars are round and even. I used the 10 sec delay on the camera to allow settling time. I only had to tweak the mount angle slightly to get SCP drift aligned. There are no flats or colour correction, not even sure if I got Registax to do it's thing properly. ( Gawd, it's complicated ! ).

So now I am on the slippery slope I think. A long way to go I know but just pleased to be able to take a pic or two. I have some more frames to work on and I'll rehash these as I learn Registax but I think Heath Robinson would be proud.

[ZeroID (Brent)]

Hmm, 40 views and no comments. I'm not surprised, you are all too polite. Looks like my posted pic is only one frame from a series, a total stuffup on my part. Cheesshh !!

So I've been playing with Registax .... for three days ! Starting to figure it out but it is seriously complicated. Has anyone seen or found a tutorial for basic processing ?

I've googled up a few but they seem to be more biased to planetary pix or avi processing with many frames. I've dredged out enough info to manage a basic process I think but I'm finding that sometimes I'm getting a ghost image appearing offset from the main object. I am only working with 4-6 frames, using manual multi point selection and very minimal picture enhancement.

Nonetheless I am getting a better picture although I am not going to embarrass myself again with a lousy pic post. Still pleased with the tracking of my little setup all the same but a lot to learn and a long way to go.

[Visionoz (Bill)]

Yes you are right - Registax is more for planetary work - use instead DeepSkyStacker which is freeware; and read the guide/help; in fact the default settings in the software allows you to get pretty close good results right off - indeed you should try to "stack" more subs to get better results

From the little I can see from your image - tracking seems alright for a 6sec shot though exposure could be more - 30secs or more would capture far more details etc

HTH
Cheers
Bill

[mswhin63 (Malcolm)]

Keep it up, I have a similar mount and have converted mine to motorised ready for a grab and go. My motor is a 1 RPM but have a server controller with a 10 turn pot control for fine tuning.

The link below is a couple of photos I took from my 450D on this mount, They are presentable not perfect and for a starter project I was expecting much.

The link were captured 60 seconds and there is a small drift but not objectionable. I recently tried a 120 second shot and the tracking was great but the alignment sucked big time, thats what happens when setting up in the dark.

Careful 15MB downloads - http://www.waelect.com.au/mswhin63/M...n/index.html#1

If you are looking for professional photos then we would need to consider a EQ5 or 6 mount or better. I use DSS as well much better for alignment. Colour balance is harder though.

[ZeroID (Brent)]

Cheers Bill, Malcolm for the encouragement.

I'll download DSS and see how that works, thanks for the pointer. I'm a long time photographer with plenty of Adobe/Gimp/PaintShop Pro software available and enough experience with it to play colour balance.
I'd already figured I needed longer exposures and I think I can get 30 secs + with accurate tracking. Also need some shorter to get detail I think. If I could just make the clouds go away ...

I'd love to go with a serious mount but it's way outside my budget. The wooden legs on the tripod are an 'upgrade' from an older tripod and were much more stable than the original aluminium set. And I have now added a very heavy weight (a small anvil !) slung beneath through the centre point to increase stabilty and reduce vibration and settling time.

But I do have another ATM idea in mind with a short heavy length of concrete sewer pipe ( unused !) and a large concrete slab already in my backyard. Think of the Sewer Pier concept. And piles of hardware junk and tools in the garage.

Better go get DSS now.

Thanks again.

[ZeroID (Brent)]

DSS is brilliant ! Piece of cake to use after Registax. Stacked all 10 frames of my Orions Sword despite 6 being well off centred. Played with RGB to regain some colour in the R channel and saturation in them all. Then enhanced colour depth in Paint Shop Pro 6 which brought up more of the dust/gas area.
Now I got to get some cloud free time and some longer exposures.

I'm even brave enough to post the processed pic, it's heading in the right direction.

[mswhin63 (Malcolm)]

Cool stuff, good luck with it, wide-field is a great starter for AP. I am now starting to zoom in a little more.

[irwjager (Ivo)]

Neat little project!

If you're desperate for recording more photons and accurate tracking is an issue (prohibiting longish exposures due to trailing) then there's a technique called binning that will trade off resolution for exposure and/or noise reduction.

The idea is that you create a more accurate 'super pixel' from sampling several smaller pixels. Dedicated CCDs usually have a 2x2 binning mode at the hardware level, but the same (minus CCD read noise benefits) is achievable in software.

[ZeroID (Brent)]

Starting to really enjoy this AP stuff. I've got a Celestron Nextimage camera on it's way ( second hand from another IIS Member ) so more options coming up. AVI through the 10" is next and stack the frames.

I'll look into this 'binning' procedure, I've seen it mentioned quite a bit but haven't followed it through as yet. I've been using the 'Unsharp Mask' at 1.2% to slightly sharpen up the final pic. It seems to reduce halo slightly and as long as you don't over do it seems to do something similar.
I'll run some longer exposure/tracking tests as soon as the clouds get out of the way. I'd love to get a good pic of 47 Tuc because it is just so dense with stars so that is the first goal.

My DSLR is a Konica Minolta 7D and it has some excellent capabilities with setup but it's other big advantage is a very low noise CCD even up to 3200 ISO. I'm running at 800 at present but 1600 is easily usable and means I can still keep exposure times down. Then I need to work out how to use the dark feild exposures to find any hot spots although I have yet to see one in processing. I'm using a f5.6 70-300 Zoom at about 160mm.

Cheers again for the help.

[Moon (James)]

Brent
Keep at it, you're on the right track. Stick with the DSLR, DeepSkyStacker and wide field - just try to get longer exposure times. The wider the field of view, the easier it will be to get longer exposures.
I wonder if you could somehow do manual guiding with that blue scope while taking images with the camera? Could be a cheap option for you if you can get it working.
James

[ZeroID (Brent)]

Hi James, if you look at the first pic you'll will see the little 240vac 1/10 rpm motor attached to the RA drive shaft. It already tracks reasonably well but I'm going to increase the exposure time significantly so I will need to keep an eye on it. I use the blue scope (Dodgy modified Chinese 114 Newt) to find and check alignment with target between frames (or during exposure). My big issue is to get a good polar (drift) alignment to reduce trails during a exposure.
Celestron unit should arrive next week so whole new bunch of problems to resolve then.