Hi Robin,
Hope you had a wonderful holiday. I’ve been experimenting with different flats for the 533 and the results are better. Last night I was doing eaa and started a stack and the over correction showed up badly in red around image. I then noticed the wb was set to balance rgb with live stack sliders in neutral . I turned wb back to 50/50 and restarted stack no more over correction showed. I’m starting to think maybe the Optolong lquad filter is causing the flat issue. Any way the best flat settings seem to be 20k adu 0 gain, 5 offset, 1 sec exposure wb set to 50/50
Asi533mc pro flat issues
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Re: Asi533mc pro flat issues
Hi,
just an update from my side on the unexplained failure of flat correction to deal with the darker right hand side of my images shown in post #8 above...
I think I have worked out the reason for this problem - flat correction didn't work on this dark area because the obstruction causing the darkening wasn't inside the telescope, it was outside... I have my deep sky scope mounted side-by-side with a longer focal length scope that I use for solar imaging. I'm fairly sure that the missing light leading to the darkening on the right hand side of the image was due to the the front of the solar imaging scope blocking some of the sky from the point of view of the deep sky scope.
I have now adjusted the dual mounting, pushing the deep sky scope forward a couple of inches on its dovetail plate and taking the solar scope back a bit - I think that should clear the obstruction and therefore resolve the issue, but I will have to wait for a clear night to actually try it out!
cheers,
Robin
just an update from my side on the unexplained failure of flat correction to deal with the darker right hand side of my images shown in post #8 above...
I think I have worked out the reason for this problem - flat correction didn't work on this dark area because the obstruction causing the darkening wasn't inside the telescope, it was outside... I have my deep sky scope mounted side-by-side with a longer focal length scope that I use for solar imaging. I'm fairly sure that the missing light leading to the darkening on the right hand side of the image was due to the the front of the solar imaging scope blocking some of the sky from the point of view of the deep sky scope.
I have now adjusted the dual mounting, pushing the deep sky scope forward a couple of inches on its dovetail plate and taking the solar scope back a bit - I think that should clear the obstruction and therefore resolve the issue, but I will have to wait for a clear night to actually try it out!
cheers,
Robin
Re: Asi533mc pro flat issues
Robin,
I’ve found a similar problem with my 533 I was putting light panel directly on top of dob for flats. Then putting dew/light shield on for lights. With the 183 never had problem but the larger sensor on the 533 caught it. After correcting that the flats were much better I still did a lot of experimenting and research on flat theory. The 533 seems to be very sensitive to average value of histogram on flats. And if the hgc and lgc of the flats and lights don’t agree there are issues. Bias correction of flats seems better than dark frame. My flats look much better my current settings are 42000 avg histogram, gain 102, offset 10, temp-10c, wb50/50. For lights I’m using 200 gain everything else matches flats. I use a lquad for both
I’ve found a similar problem with my 533 I was putting light panel directly on top of dob for flats. Then putting dew/light shield on for lights. With the 183 never had problem but the larger sensor on the 533 caught it. After correcting that the flats were much better I still did a lot of experimenting and research on flat theory. The 533 seems to be very sensitive to average value of histogram on flats. And if the hgc and lgc of the flats and lights don’t agree there are issues. Bias correction of flats seems better than dark frame. My flats look much better my current settings are 42000 avg histogram, gain 102, offset 10, temp-10c, wb50/50. For lights I’m using 200 gain everything else matches flats. I use a lquad for both