Quote:
Originally Posted by CalvinKlein
Good images Gavin. Looks to me like your subs are way too long. I'd suggest taking many more but at shorter duration (something I wish I learned a year ago). All your stars appear saturated which is a tell-tale sign. 5 min is a long time unless your target is in very un-light polluted region of sky. Instead of 26 x 5 try 130 x 1min. You only need to expose each frame so that your background sky level is 10 to 20 times your read noise. As others have said you ideally need more integration time too. to increase your signal to noise ratio. Have you read the CloudyNights forum threads on the optimum exposure settings for CMOS cameras ? Very worthwhile studying. (oh and colour cameras need MUCH more exposure time than mono cameras unless the sky is very, very dark where you are imaging)
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That's really intersting to hear Kalvin. I think I'll also have a look at that CN thread but what you're saying makes a lot of sense. I have persevered with my unsmooth mount that can only give me 25 odd second frames consistently basically for that reason with light pollution. Sometimes I take long ( 1.5 min ) exposures with star movement just to check the framing of my target but the sky glow is horrible. I learned over time that I could get some satisfying images with 25 second subs, I just need to take a bare minimum of 500 of them even on mag 6 objects. I'm now aiming at mag 8 targets so I imagine I'll need maybe 7-800 which I'm fine with. Jeez this game is fun
