ASI294 overexposed? Vignetting/weird colors even with flats

[BlackWikkett]

Have a look at viewtopic.php?f=16&t=1372

Here you'll see images which were saved as seen from SharpCap Live Stack as 8 bit PNG. Several of the images were then additionally processed in Photoshop to address further color balance, noise reduction and possibly some additional slight stretching.

These are not perfect by any means but does show the power of well calibrated live stack images when dark and flats are working properly.

[ippiu]

The image attached to this post didn't render

ASI294 for flats try these settings. 0 brightness, gain 150-300, exposure 250 - 350 ms. Exposure time and gain settings really depend on what you're using to illuminate your scope to take your flats. Use the SharpCap flats tool and turn on the histogram. In SC flats tool use Bias, and mono. Adjust the exposure and gain to that the white channel peak is in the middle, 50% on the horizontal scale, and your highest color channel doesn't clip the right side of the histogram.

Since i've been starting using seriously SC 6 months ago, i usually did my flats as Blackwikket said, except:
- brightness set to 10 (i usually keep it to 10 also in lights and darks)
- exposure 500 ms

but flats don't work always properly. Better, they work 50% of the times: some nights they aren't useful and i don't know why.
As i asked here, but with no answer...
viewtopic.php?f=5&t=1535&p=8081#p8081