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strgazr27
1st of June 2009 (Mon), 19:41
I had my wife roll the roof back on the observatory and I managed to grab 400 minutes of M101. The skies weren't great but this is THE best shot I have ever taken of this object. It's both tough to shoot and process. I'm going to rework it again tonight as it's a little noisy. Comments welcomed :)

http://strgazr27.zenfolio.com/img/v3/p334941260-4.jpg

A.S.I.G.N. Observatory
1st of June 2009 (Mon), 20:43
I wouldn't knock yourself so hard mate. That's a great image. Maybe a touch on the green side (very slight).

Lovely and sharp. Tracking is spot on. Nice round stars.

Baz.

Celestron
1st of June 2009 (Mon), 22:42
Fantastic shot strgazr27 ! Beautifully done !

chris.bailey
2nd of June 2009 (Tue), 02:50
Agreed. Cracking image.

Adrena1in
2nd of June 2009 (Tue), 11:06
Crikey, that's very impressive.

joaquimsrs
2nd of June 2009 (Tue), 18:45
Hi,

I'm sorry but I have a really newbie question. How is it possible you took 400 mins of this galaxy? I mean doesn't the galaxy move on the sky? How do you manage to rotate the telescope? And how many photos did you take? Why did you need to take so many photos? Wouldn't 1 long exposure photo be enough?
I know that this may be a real dummy question, but I really would like to understand.

Thanks

JS

jmx
3rd of June 2009 (Wed), 05:52
Hi,

I'm sorry but I have a really newbie question. How is it possible you took 400 mins of this galaxy? I mean doesn't the galaxy move on the sky? How do you manage to rotate the telescope? And how many photos did you take? Why did you need to take so many photos? Wouldn't 1 long exposure photo be enough?
I know that this may be a real dummy question, but I really would like to understand.

Thanks

JS

To counter the rotation, you use an equatorial mount. See cloudynights.com's forums for discussions of this. You can also see my thread posted on this forum yesterday with my first galaxy shots, and I list the exact equipment I used (which is pretty much the cheapest setup available).

1 400 minute exposure would be nearly impossible due to satellites streaking through your photo, planes, or imperfections in how the equatorial mount tracks (things still drift slightly over time and have slight errors), not to mention the noise you'd get in 400 minutes! By taking 100 4 minute shots, you get the same amount of photons, but you have 100 samples of random noise. You can then average the 100 shots together (its called "stacking"), the noise turns to a paternless low signal, which you can edit out easily in photoshop, and everything else is pure signal....ie, the galaxy. The other upshot is if a plane flies through your shot, you only ruined 4 minutes of exposure, not 400!

cloudynights.com's forums are where I picked up all the info to shoot my first shots, there's a DSLR specific sub group on there with good info.

joaquimsrs
3rd of June 2009 (Wed), 07:33
Thanks jmx. I got it now. will check the link as well.

Cheers

MidnightSun
3rd of June 2009 (Wed), 18:26
Very nice shot.!!..perhaps a tad green, but I'd be happy with it. Just something to fool with on a cloudy night....:D

Sky Hye
5th of June 2009 (Fri), 18:28
I know many of you are seasoned Astrophotographers with years of experience under your belts.

Can any of you direct me towards some resources on taking photographs like these, (obviously not with an observatory). I'm lookin gat maybe a 6-8" SGT scope and already have a canon 500D. Any help would be much appreciated.

jmx
5th of June 2009 (Fri), 18:30
cloudynights.com

Celestron
5th of June 2009 (Fri), 23:32
Jerry Lodriguss (http://www.astropix.com/HTML/I_ASTROP/TOC_AP.HTM)
The Digital Camera Astronomical Imaging FAQ (http://mysite.verizon.net/~vze4r2c2/Astro/AstroDigiCamFAQ.html)

Sky Hye
6th of June 2009 (Sat), 00:03
Thanks Celestron, looks like alot of learning to do! Can anyone recommend a good scope to begin with for some galaxy viewing?

chris.bailey
6th of June 2009 (Sat), 03:31
Thanks Celestron, looks like alot of learning to do! Can anyone recommend a good scope to begin with for some galaxy viewing?

http://photography-on-the.net/forum/forumdisplay.php?f=126 has been discussed lots of times with pretty consistent advice I think