Flats and Darks with bin=2 have changed height in SC 4.1

[ChrisR Oz]

Hi Robin,

I upgraded to SC 4.1 and now profiles that use bin=2 do not load correctly. I get this error pop up ...

Bin2 load flat error

bin2 flat error.JPG (21.97 KiB) Viewed 6237 times

It would seem that SC 3 must have created Darks and Flats for the ZWO 294MC Pro (4144x2822) with size 2072x1410, not the height expected by SC 4.1 of 1411.

Perhaps SC 4.1 could be a little more "accommodating" ...

Mystery Solved?
However, this does solve a mystery for me, possibly. I reported strange histograms with satellite peaks, which I tracked down as due to row=0 in the image. But these were not bin2 images. However, perhaps some errors in frame height in the old SC have led to both poor Dark and Flat frame heights in bin2 and also faulty subtraction of Darks in bin1 just for row=0. Did you fix something like this?

Cheers, Chris.

[admin]

Hi Chris,

the issue here is/was that the older version of SharpCap wrongly applied the (somewhat complex) rules for how width and height need to be chosen on a ZWO camera. These rules depend on the level of binning and whether the 'hardware binning' option is off or on. If you don't apply all the necessary rules, the camera won't work. If you apply them too strictly - which is what I was doing previously - then resolutions don't match those in other programs.

Of course, fixing this issue has meant that the resolutions produced by SharpCap itself have changed

Now, SharpCap is supposed to cope with the flat or dark being at full resolution and the camera running at ROI, but I'm not sure if I have ever checked that code to see if it works in binned modes - it might not be looking at the binned resolution. I will check.

The other thing that might rescue you is turning on 'hardware binning'. That applies stricter rules, including that the height of the image must be even, so that might push SharpCap 4.1 to capture at 2072x1410 rather than 2072x1411.

cheers,

Robin

[ChrisR Oz]

Hi Robin,

Not sure exactly what you mean by 'Hardware binning". I use a ZWO 294MC Pro and have binning set to 2 in "Capture formats and area" (this is for shorter exposure plate solve during setup on a target). I thought this was hardware binning. This camera does not seem to have a "Hardware binning" mode control, as mentioned in the SC 4.1 manual. It does have a "Mono bin" control. But that is not discussed in the manual. Is that what you mean?

Cheers, Chris.

[admin]

Hi Chris,

unfortunately I don't have a ZWO 294MC to test with, so can't check whether it should have hardware binning. If your camera does have one then it will appear under 'Turbo USB' in the Camera Controls section. Setting that control to on (if present) means that the binning is done on the camera, rather than in software on the PC. The end result is the same except that with hardware binning you might get higher frame rates if that is important to you and you are subject to more rules about ROI size.

If you are still not seeing a hardware binning control, please could you send me a log of the camera being opened, then put in BIN2 mode, with the additional logging of 'camera hardware communications' turned on in the settings before opening the camera. That should give me enough info to investigate further.

thanks,

Robin

[ChrisR Oz]

Hi Robin,

I simply regenerated the Dark for the bin2 mode, and SC 4.1 produced the correct size image, which works fine.

I believe the new behaviour is more straightforward and logical, so will not worry too much about the differences for now and the lack of a “Hardware binding” mode. It simply works fine now.

Thank you.
Cheers, Chris.