|
Focal Reducer/Adoptive Optics
I am trying to use a 0.8 focal reducer/corrector that recquires a precise separation of 97.5mm between it and the CCD sensor in conjunction with a Starlight Xpress AO unit. The latter has a multi-coated AR bloomed plane-parallel optical window with a thickness of 12mm and a diameter of 40mm. This requires the separation to be increased by 4.1mm to compensate for its optical thickness. With this done I am still getting distorted stars in the corners of the image after repeatedly adjusting the separation by small amounts to optimise the image. This is using an APS sized sensor which the reducer is supposed to be suitable for.
So the question for any optical gurus is this - is there a fundamental conflict in using these two items together (telescope is a Meade LX200GPS) or do I need to persevere?
|