Here is an NGC4945 taken tonight in clear dark skies - 12x5min subs with a 1000D on a 200mm RC (GSO) at ISO800. Guided. There are several things wrong that I can't figure out. One is the obvious oval-shaped halos of light in the upper left and center bottom. Also, the diffraction spikes seem to me to be OK in one direction but double in the other. The starsare reasonably round so I don't thnik guiding is really a core issue.
Any ideas?
The diffraction spikes are caused by the collimation.. it seems that the collimation has somehow gone out slightly since you picked it up... the oval halo's are caused by reflections inside the scopes baffle tube.. these are easily fixed by flocking the primary baffle tube... It would take less than an hour to complete the flocking, and that problem would be gone...
Guiding looks spot on...
Next weekend I'll explain the flocking procedure a bit more, and if you like we can possibly get the mod done within a couple of weeks if you want a hand....
Collimation I can sort out this weekend for you.. Takes 5 minutes and will fix up those diffraction spikes...
