I have a CPC1100 and bright stars/planets all have a strong green tint to them. I bought the scope used and it had a spot of clear goo like substance on the secondary. i removed the corrector plate and cleaned the spot with a mixture of 50% alcohol and 50% distilled water. The primary, secondary and corrector plate all look clean without any green tint to them under normal lighting. The only thing I can think of is that there might be a thin film still left on the secondary that is causing the green tint to bright objects at the eyepiece. If anyone has any advice on how to better clean the secondary or what else could be causing the green tint, please let me know. Thank you.
Edited by adamsdp, 05 January 2019 - 09:04 PM.