http://www.myastrophotography.com/2009/m51-second-attempt/ Astrophotography | Astronomy | Astro Equipment | Reviews | Tutorials | News Thu, 15 Apr 2010 00:02:48 +0000 http://wordpress.org/?v=2.9.1 hourly 1 http://www.myastrophotography.com/2009/m51-second-attempt/#comment-2908 Phil Tue, 21 Jul 2009 17:15:40 +0000 http://www.myastrophotography.com/?p=271#comment-2908 Excellent photo! You are an inspiration! Excellent photo! You are an inspiration!

]]> http://www.myastrophotography.com/2009/m51-second-attempt/#comment-2508 Ivan Pankov Sat, 20 Jun 2009 17:16:57 +0000 http://www.myastrophotography.com/?p=271#comment-2508 good to know, thanks for taking time to explain. good to know, thanks for taking time to explain.

]]> http://www.myastrophotography.com/2009/m51-second-attempt/#comment-2484 admin Fri, 19 Jun 2009 23:38:00 +0000 http://www.myastrophotography.com/?p=271#comment-2484 Because of the thermic noise. All the CCD detectors have so called 'hot pixels' which show the signal despite there was no any light source. The longer exposure is, more noise you have in the picture. If you take some light frames and some dark frames (pictures with cap on the telescope) you can remove the noise when processing the pictures (the tutorial follows). And there is another reason. If I take 1 picture 1h 30min that means the same time of perfect guiding, no satellites, airplanes ect. If there is a error in a 5min exposure or airplane or satellite trail I simply delete it. Because of the thermic noise. All the CCD detectors have so called ‘hot pixels’ which show the signal despite there was no any light source. The longer exposure is, more noise you have in the picture. If you take some light frames and some dark frames (pictures with cap on the telescope) you can remove the noise when processing the pictures (the tutorial follows).
And there is another reason. If I take 1 picture 1h 30min that means the same time of perfect guiding, no satellites, airplanes ect. If there is a error in a 5min exposure or airplane or satellite trail I simply delete it.

]]> http://www.myastrophotography.com/2009/m51-second-attempt/#comment-2480 Ivan Pankov Fri, 19 Jun 2009 19:59:25 +0000 http://www.myastrophotography.com/?p=271#comment-2480 Why do you have to split them? Why not 1 photo with 130 mins exposure? Why do you have to split them? Why not 1 photo with 130 mins exposure?

]]> http://www.myastrophotography.com/2009/m51-second-attempt/#comment-2456 admin Fri, 19 Jun 2009 01:20:08 +0000 http://www.myastrophotography.com/?p=271#comment-2456 Exactly as you said. 26 subexposures, each 5min long. Exactly as you said. 26 subexposures, each 5min long.

]]> http://www.myastrophotography.com/2009/m51-second-attempt/#comment-2453 Ivan Pankov Thu, 18 Jun 2009 23:45:15 +0000 http://www.myastrophotography.com/?p=271#comment-2453 Looks fantastic, I definitely will get a backyard telescope later this year. Could you explain what 26 x 5min exposure means? 26 photos with 5 mins exposure? Looks fantastic, I definitely will get a backyard telescope later this year. Could you explain what 26 x 5min exposure means? 26 photos with 5 mins exposure?

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