Hey Richard,
Thanks a lot!
The next time I will use more focal length for a higher resolution.
At the same day I photographed the venus with a special UV Venus screen.
The screen should show some structures in the cloud cover, but it just effected a very dark look of it.I think the screen is to narrowband for my "little" dobsonian.So I have to sell it and look for a better one.
Anyway I want to see details on venus' surface.
Bye, Andreas