Page 3 of 3

Re: Understanding Binning

Posted: Fri Feb 21, 2020 2:58 am
by joeastro
HI.. very good.. but you missed the point.

when do you bin?

as the raw image cmos is read out to a full frame image? do you bin that first?????
then apply dark flat bias???


do you bin last? what isthe noise after you bin after you calibrate the image!!!!

nosie should be slightly better as your not workign with the raw image.

now the problem with sharpcap...
when you select a frame size, and then click a binning.. the software runs
out and checks the flat and dark.. and pops up a warning that th flat and dark
do not match the FRAME SIZE??? but you dont say if the frame is fULLLLLLLL size
when i check 5000x3000 pixels and 2x2 binning..


the 1x1 flats and darks i took dont match the final image 2x2 binned ..

which means i have to take dark and flats all over again???

will you tell us what the software order of binning and flats and darks...etc...DO!
in what order and why you cant scale 1x1 flats and darks so we dont have to do over do over do over.

trying to use sharpcap

Re: Understanding Binning

Posted: Fri Feb 21, 2020 9:28 pm
by admin

The golden rule is to always treat all the different types of frames in the same way – if you're going to capture your light frames 2 x 2 binning then you must capture your dark, flat and bias frames at the same 2 x 2 binning setting. It's not worth the risk of trying to reuse unbinned calibration frames – you can certainly load them into some piece of software and apply some sort of digital binning to them, but there's always the chance that it won't be done exactly the same way as the binning on the camera which would then lead to problems with either dark subtraction or flat correction. As I say, not worth the risk.

Cheers, Robin