|
Well if it is the 250mm dob that your using then the answer is yes, its to do with the hyperbolic nature of the mirror that light hitting the outer 1/3 of the mirror focus's at a different part.
If your doing photography i suggest you invest in a 250 dollar MPCC (Mulit purpouse Coma Corrector) this will clean up the image and is designed for newts with a f# between 4 - 6 with f5 working the best.
Good luck
|