Mosaic structures with ASI178mm

-dako-

Hello,

I am using a 120 f/7.5, Quark Chromo, Zwo ADC and ASI178MM with Firecature. The combination worked witout any problems, but yesterday (without changing anything in my configuration since the last usage some days before) I got mosaic structures in my pictures. The structures are there before stacking and trying to change the settings of the ADC did not solve the problem.

Here is a picture if the problem (100% crop of an image without anything else changed):

Does anyone have an idea how to solve this problem?

Thanks!

David

Sam@ZWO

maybe you apply gamma(not 50)?

pdb

Only noticed this thread yesterday. This hatched pattern is a problem with the 178MM and has nothing to do with Gamma setting. Though it will make them more visible if you enhance contrast, but this is also the case in post processing. (seen other user on other fora complain about this). I (try to) use that camera for solar, and never see the pattern when imaging in white light (Astrosolar filter or green solar continuum + Baader Astrosolar) When I switch to Ha the pattern is very visible. The only way to (sort of) get rid of it, is to rescale the image. If you scale at different sizes you will see the pattern come and go. (also depends on the level of Lucy-Richardson and/or Unsharp Masking applied). Agree that is only some cover up of the problem but it helps. Also Fast Fourier filter in post can help, but that is a lot of work ....

At one moment even thought it looked as if the sensor had a Bayer Mask and debayering done in Black&White. This would explain why this is only visible in Ha. But I wonder is Sony would produce B&W versions of the sensors beeing actually color versions with modified circuitry. Might also have to do with the angle of light hitting the micro-lenses but then it will probably change wit f/number. Did not try that yet.

Regards,

Paul