SharpCap Forums

Hi Robin,

I didn't see anything "weird" between 350ms and 360ms. I dragged the slider through the range and also manually stepped it up by typing in the exposure in increments of 1. In all cases, there was the short pulse of light and then it would settle down.

Thanks,

Greg

Hi,

Okay, I'm afraid I can't think of much else to try at the moment. While I could make SharpCap less fussy about getting the exact target brightness it's looking for, I think that the end result of that would just be to get poor data out of the analysis routine (essentially we'd be allowing bad data to go into the calculations where currently is being rejected).

I can see that some people have had success in getting the sensor analysis to work with the QHY294 camera, so I should be able to get the sensor details into the library for a future version of SharpCap.

Cheers, Robin

Hi Robin,

I decided to give it one more try - this time outside with the scope pointed at the grey, cloudy sky in Seattle. The analysis worked, but only once. The results are attached. Please let me know if you see anything "weird" with them. I'll try and re-run the test after the holidays.

Thanks,

Greg

Hi Greg,

That looks pretty much as I would expect for a 294C sensor – the big drop in read noise is characteristic of the sensor switching from LCG to HCG mode typically at a gain of about 9.0x minimum.

Cheers, Robin

I have the same camera and I'm having the same issues. Adjusting the light level is beyond finicky and I've yet to make the camera pass the gain test stage. Otherwise it seems a solid performer with SharpCap!

Robin, did you have the chance to discuss this with QHY?

TIA

Hi,

I must admit that I haven't – I have tried tweaking the analysis routines to be less strict about the brightness level they want in the upcoming version of SharpCap (3.3) which may help get past this sort of problem at the cost of slightly reduced accuracy.

Cheers, Robin

admin wrote: Thu Jul 02, 2020 7:51 pm I must admit that I haven't – I have tried tweaking the analysis routines to be less strict about the brightness level they want in the upcoming version of SharpCap (3.3) which may help get past this sort of problem at the cost of slightly reduced accuracy.

That's OK Robin, I will test 3.3 and report the results here.

Just to pile on here. I have a QHY247C and the sensor analysis works up until the very last step. Whenever it increases the gain to the maximum, 4096, the image goes white with some noise speckles and it continuously reduces the exposure until it can't any more and it fails. I also noticed the same response when doing the dark frames. Everything is fine all the way up until gain 4000, but when it hits 4096, the image goes white. I believe it to be an issue with the camera and not your software, but I'm not sure what the fix is.

Hi,

you are using quite an old version of SharpCap – could you please try updating to the latest version from the downloads page and then see if you get any better results. One of the changes since the version you are using is that SharpCap does a pre-measurement of the effect of different gain values and it should lock out the very high gains on your camera for exactly the same reason that is causing the failure in the log that you have posted.

Cheers, Robin

admin wrote: Sun Sep 27, 2020 7:20 pm Hi,

you are using quite an old version of SharpCap – could you please try updating to the latest version from the downloads page and then see if you get any better results. One of the changes since the version you are using is that SharpCap does a pre-measurement of the effect of different gain values and it should lock out the very high gains on your camera for exactly the same reason that is causing the failure in the log that you have posted.

Cheers, Robin

That seems to have solved it! Thank you, Robin! I didn't realize my version was quite as old as it was.