Hi, I am considering the STC-7, but my question would apply to any of your StackPro cameras. If the image is an internally stacked of 16 subs the bit depth increases from 12 to 16bit. So one saved image of 480s is a stack of 16 x 30s subs with a bit depth of 16 bits. If I take matching darks each downloaded dark will also be a stack of 16 subs and be 16 bits. This seems okay. Is the file downloaded as 16 bit or perhaps 32bit? For flats, my experience is that 2 seconds gives me 50% saturation with my light panel. Would this be divided into 16 x 125ms internally and downloaded as a 16 bit flat frame? If not, then the bit depth will not be matching when applying the flat to the light frame. So my question is if different bit depth have any calibration consequences of StackPro vs non StackPro captures? Maybe I am self answering my question, because if I take a 480s light frame (no StackPro), I calibrate each with a 480s master dark of 20 darks. The stack of 20 darks will have a bit depth much higher than 12 bit single light frame. This is proper to do. Can StackPro stack more than 16 subs, and have more than 16 bit depth? Then would the file be saved as 32bit? StackPro is very intriguing, and I just want to get the better overall picture of what I will do (differently?) in my processing, including providing flats, and providing darks & flat darks. Thanks and regards, Roger
The file is downloaded from the camera as 16-bit. There is no consequence to having a different bit depth for the flat fields. You MUST take and apply a flat-dark, i.e. a dark that matches the exposure conditions of the flat. MaxIm DL knows how to handle that properly in its calibration command. StackPro is limited to 16 subs, resulting in a 16-bit image. That is by design.
Hi Doug, Thank you for your reply. StackPro is a new and exciting area for CMOS imaging! I looked, but could not find the answers for these.... Edit: Oops!, I just read the Readout Mode for calibration frames should be same as the lights. So my questions are now... Based on StackPro readout mode for my light frames. --- It normally takes about 16 second flat duration for my narrowband filter (without StackPro CMOS camera) to get about 40% of full well depth. If I used StackPro readout mode, will I still get the 40% full well depth, or need to adjust the total exposure? --- For my typical broadband flat I have 2.3 seconds. StackPro would then divide this into 2 x 1.15 subs? Please confirm 1 x 2.3 sec sub would not work because I would be using Normal readout mode to get this result (for calibrating my StackPro light frames)? Thanks, Roger
Flat fields can be taken in any mode you like, but whatever you do, you need to take matching flat-darks - same exposure, same readout mode. Personally, I'd just use a normal exposure. Of course you would take a bunch of them and average. Same answer as above Dark frame exposure mode MUST match your light frame exposure mode
Doug, Thank you for your quick and clear answers. I will use matching flat darks, and follow your other advice. Roger
