SharpCap Forums

I was using a QHY163C camera with SharpCap. A week ago I did the sensor analysis in Sharp Cap, and wanted to test out the optimal exposure calculation in SharpCap. After this last DLL/sharpcap update, I noticed that after changing the exposure time or gain, that the first frame is completely dark. So when SharpCap is trying to measure the optimal exposure, it sees a completely dark frame and tries to increase the exposure till it measures a good signal above the noise. It keeps trying and increasing the exposure as it is measuring up to 1000 seconds at gain 500 and of course sees a dark frame after each try.
What is happening? How can this be fixed? Is it a SharpCap issue or QHY DLL issue?

Thanks

Hi,

My first question is... do you have the very latest QHY drivers? I had problems with the new SDK version until I update the drivers to the latest version. If you are up-to-date on drivers then I would be tempted to work through some tests with adjusting the USB settings in case a value that worked in the previous SDK/driver is causign issues with the newer version.

cheers,

Robin

Thanks Robin,
I'll check that out.

Eric

I was about to head out tonight for some imaging and tested the optimal exposure time with the little brain with my QHY224C camera. The problem my friend was having is now happening with my camera too. I even tried a newer DLL from 10 May, 2018 and am still having the same problem. Unfortunately, the idea is good but QHY/SharpCap is not playing nice.

Ahh, I think I see... during the sensor analysis, SharpCap waits for a few frames after making a change on the grounds that sometimes the first few frames come in with the old settings (or are dark as you mention). In the sky brightness measurement it does the same, but then stops doing it when the exposure exceeds a certain point to avoid the procedure being very slow, but that backfires in this situation.

WIll see if something can be worked out.

cheers,

Robin

Have a go with the latest version out today. I have made a change so that if the exposure is increased and the next frame comes in darker instead of brighter then it will skip that frame and wait for the next. Hopefully this will resolve the problem.

Cheers
Robin

Thanks Robin,
I tried it on my QHY224C and my friend's QHY163C and both are working well.
Eric.

Excellent news - thanks for reporting back.

cheers,

Robin