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drevilsmom
26th of October 2008 (Sun), 19:23
So I had some time this morning before work and I went to take a few shots of Orion. Took about 20 six second exposures with my kit lens before I was pushing time. Downloaded them on the computer and found only 5 that were useable for stacking and ultimately stacked only 4. Note to self: Must get a new tripod as my camera kept shifting. Stacked them and was generally pleased, but still feel like I'm missing out on a LOT of detail. What can I do to push the limits of getting detail out of short unguided exposures? I'm guessing lots and lots of images to stack, but doesn't it eventually lighten up the stars and blow them out? Do I need to take equal numbers of dark and flat frames as well even in constellation photos and stack them with it?

Here is my second feeble attempt at astrophotography with my 40D.

http://i154.photobucket.com/albums/s254/drevilsmom/orion1.jpg

fireird7o4
27th of October 2008 (Mon), 13:32
Oh wow its so clear! Is a shot like this possible with your powershot? I have one too ( S5 IS ) and im still learning.

Nighthound
27th of October 2008 (Mon), 18:47
Nice job Elizabeth. Do you have Photoshop?

drevilsmom
28th of October 2008 (Tue), 08:41
Nighthound, No I do not. And this just came straight out of the stacking program. When I do edit, I use the program that came with my S1 IS, ArcSoft Photostudio 5.5. Wasn't really sure what I could do to enhance it. $600 for a new program would definitely get a no go from the hubby. I barely was able to buy the camera without making him too mad. It helped that my S1 IS had chose to die at that time. Right now I'd rather save for a new lens.

And fireird7o4, no this was taken with my 40D. I've tried with my S1 IS in the past, and it just does not have the capabilities (or at least I was unable to get it to work!)

Nighthound
28th of October 2008 (Tue), 09:06
The reason I asked is because stacking is just a piece of the process. Stacked images contain much detail that can be coaxed out in programs like Photoshop. I did a simple curves adjustment on your shot and many fainter stars became visible as well as more of M42. All I did was raise the black point(low end values). When the black point becomes too clipped it floods the black areas to a point where faint detail(in this case mostly stars) is lost. It also makes those nice glowing stars begin to take on a harder edge. You don't need to push the black to 100%, space is not pure black although I know it's tempting to make those stars pop. I keep my black somewhere between 80%-82% value.

I'm not familiar with Arcsoft Photostudio but have you looked at this, it's free and have heard that it is effective although more limited than Photoshop of course. Maybe it'll have features that Photostudio does not.
http://www.gimp.org/

Adrena1in
31st of October 2008 (Fri), 13:45
Here is my second feeble attempt at astrophotography with my 40D.

That's by no means feeble. It's as clear as anything, and much better than any Orion Constellation shot that I've managed. Without a tracking mount you are unfortunately going to be limited to relatively short exposures, and sometimes no matter how many short exposures you take and stack you might not be able to get much more detail out.

The shorter and shorter focal lengths you go to will allow you more exposure time before trails set it, and if you can get a lens with a massive aperture that'll help too. I recently invested in a cheap 50mm f/1.8 lens, which is excellent as it lets oodles of light in with very short exposures. (My first tests at 15 or 20 seconds were really over-exposed.) It'll make quite a good constellation lens.

What you might also try is if the constellation is too big, (Orion simply isn't Orion without the fabulous star which is somewhere in the vicinity of the home of Ford Prefect! ;) ), is taking several shots and making a mosaic of them all.

Keep at it though, you're off to a great start I think.

drevilsmom
31st of October 2008 (Fri), 20:17
Thank you for the support, Adrena1in. Astronomy has always been a passion of mine. I guess I can blame my grandfather on this one. He flew Corsairs, Hellcats, and Wildcats off of the USS Tarawa (CV-40) in the South Pacific during WWII, and although he never saw combat, he rarely would talk about anything he experienced or learned. That said, he always would point out constellations, and for some reason Cassiopeia, because since GPS obviously did not exist, they had to rely a lot on star positions during the night missions for navigation. I remember being very little and him taking me outside to show me constellations. I didn't really get involved, however, until college, where I taught a University astronomy night lab for 5 semesters.

Adrena1in
3rd of November 2008 (Mon), 02:51
That's a cool story Elizabeth. I can't say anyone taught me astronomy...I just found it interesting as a youngster and taught myself I suppose. Didn't learn much to start with, and only really knew Orion and Ursa Major/Minor. I do remember scanning Orion with binoculars and wondering what the blurry bit was on the sword, and then years later seeing a picture of M42 and being absolutely awestruck. It wasn't until a couple of years ago that I got my first semi-decent scope, and only really this year did I start to get properly into imaging. It's a massive learning curve and I don't take that well to learning, but it's all enjoyable. I certainly now know a lot more constellations now, but still probably can only identify about 10% of the ones I'm able to see from my location.

(I feel a "How and why did you get into Astronomy/Astrophotography" thread coming on! ;) )