Quote:
Originally Posted by gregbradley
Thanks Lee. Yes I think I got away with 10 minutes here but a lot of the stars are saturated so 5 minutes makes more sense.
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I'm a proponent of keeping it simple - I just shoot 5 minutes with my gear at -20c and have a library of darks and bias frames and don't fiddle with them. Same goes for flats (I haven't changed my gear config for 3 months). However, I've not been very scientific about it up to this point at all.
But, I recently watched a talk by the author of Sharpcap. It’s quite interesting in regards to exposure length calculation. Way more detail than I ever though about, and more importantly, discusses the differences between CCD and CMOS. I also like that this is based on the math and isn't based on subjective opinion.
I found the info suggesting that going "long" in my configuration was just probably inefficient, and could go much shorter (ie down from 5 minutes to 2 or so). Saves on planes/satellites etc in the subs I guess. The downside is way, way more images to stack as a result.
https://youtu.be/3RH93UvP358
There is a section on gain which he had to skip over, and then he subsequently recorded that separately. This in particular was very interesting around the discussion around gain on the CMOS sensors. Was completely counter intuative to what I would have thought.
https://youtu.be/ub1HjvlCJ5Y
If you own Sharpcap (it's pretty cheap really), it can calculate all this stuff for you (I own it, but haven't had a chance to try out the calculator yet since watching the video)