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Preview and capture

Posted: Thu Aug 10, 2017 3:45 am
by Ray Hansen
I've been using 3994 for capture from a ZWO ASI071. Today I upgraded to 4002, restarted, and tried to get a string
of dark frames. The status bar in the lower right corner cycled normally, but the capture status indicator would not
increment. I would see the first image show up, it would skip a number of cycles, then capture one or two more, and
skip a number after that. I'm running windows 10 v1703. I verified the camera was working normally, and switched to
another usb cable, without improvement. I uninstalled 4002, and reinstalled 3994, and it's working normally.

Re: Preview and capture

Posted: Thu Aug 10, 2017 8:05 am
by admin
Hi Ray,

normally I'd be really pleased to get this sort of bug report - it worked in 3994, fails in 4002, works when you go back to 3994 - excellent, just check the changes between those two versions (only 8 changes) to find the problem.

The bad news is that I've looked over the changes and there is nothing anywhere near the ASI camera code :( Most of the changes were things like extra logging to try to track down other issues seen by users and so on.

From your description it sounds like 4002 is dropping frames from the ZWO camera - so basically it gets to the end of the frame time period and the frame isn't available so it starts waiting again. Often this problem can be solved by tweaking the Turbo USB control for the camera. No idea why this would need to change with the changed version of SharpCap in this case but certainly worth a try.

I will test out with my own ASI071 later, but I haven't seen any issues with it lately. What sort of length frames were you capturing and in what format (ie RAW8, RAW16, RGB, etc)?

cheers,

Robin

Re: Preview and capture

Posted: Fri Aug 11, 2017 12:03 am
by Ray Hansen
I'm still seeing the problem today. I'm using a RAW16 space, 8 second exposures, with the turbo on auto and at 40.

On a separate issue, I was trying to force RGGB, but the fits header still shows it as GBRG, and photoshop
won't let me set an RGB color space. I've never run into this and haven't had time to study it yet. If you have
some wisdom here I would appreciate it.

Re: Preview and capture

Posted: Fri Aug 11, 2017 5:56 am
by admin
Hi Ray,

Lots of FITS reading programs interpret FITS files starting at the bottom left rather than the top left, so to give the correct pattern for these programs SharpCap deliberately flips the bayer pattern in the FITS file when saving it, so RG-GB becomes GB-RG (swapping the first and last pair of letters).

Still not had a chance to test the 071 myself yet.

cheers,

Robin