Quote:
Originally Posted by multiweb
Hi Duncan, looking good  You can get rid of the dust donuts with flat fielding. THat's what it's for besides taking care of vignetting. THe halos o the bright stars are the reflections of the glass at the back of your MPCC on to the glass of the QHY8 nose piece. Check here for more halos. Looks familiar  I'm still working on getting rid of these but replacing the nose piece by a NULL adaptor (nose piece without a glass) seems to help a great deal. |
Thanks again Marc, ok, so the flat fielding is looking better, but is still not right, i had taken the today, after storing the OTA overnight indoors, although the orientation of the camera, and focuser where not changed, so this should be fine, right? or maybe i should take them at teh exact same time as the lights, i can see that the "cosmic string" in the image has a dark and light part, so maybe this moved, when i shifted the OTA
As for the the reflection from the MPCC, i thought that, but the only thing that lets the theory down, was that i dont use any nosepiece filter on the QHY8, i use the spacing rings for the MPCC, the MPCC itself, and thats it!
Troy, thats some good advice, i will check that out to
