Flats and Dark Flats issue

I'm suspecting you do have some form of a light leakage in the system, my advice would be to really carefully check the system for lights that may cause issues, either from external sources or internal (by a led for example).

@vincent-mod 

Thanks.  I am going to try reshooting those flats.  

I'm not 100% sure of course, but it may be something that happens when taking the darks en bias specifically.

Hi

I retook the dark flat images in the dark being sure there was no light. I stacked them in APP with the same result.  I am asking in the ASI camera group if this is normal or if there is a way to deal with it.

Thanks.

An update on my issue:

I wonder why there appears to be two different size frames in my result?  In a problem solving effort I shot bias frames to use rather than dark-flats.  The result was somewhat better. Don't worry about the strange star halos. I was trying a new filter.  

Is there an APP setting that might contribute to this result?  This is a single session capture. No changes were made in the OTA.  When I BLINK all the flats, dark-flats, bias, and lights they are all the same size.  

Thanks

Hi Andy @andynowlen,

To start with, the masterflat looks definitely not okay, the flats/masterflat can have color, that is no problem at all, but that color should be even across the entire flat, it really should not be green on one side and magenta on the other side.

Your problem with the different frame sizes as you call it, is actually very normal. You must have some lights which were translated quite a bit from the other lights... and you surely have gradients/light pollution in those frames to make it more complicated.

I would suggest, the following:

in 5) Normalize, enable advanced normalization , that shoudl already give you a better result.

in 6) Integrate, enable Multi-Band Blending (MBB) 15% and enable LNC 1st degree with 3 iterations.

I think the result will be much better then 😉

Mabula