Quote:
Originally Posted by Slawomir
I think there is some variation in FL in every scope, in particular when lenses are hand-figured for optimal optical performance.
Another way to quite accurately measure FL is to plate solve an image with a star field, but the image should be taken without a corrector as I feel some correctors may slightly alter f-ratio.
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Sauvi, yes as you say but I would have to image! Would it be easy to pick up the difference between 915mm and 935mm given a DSLR image?
This morning I rigged up my scope with measuring rod attached and projected the sun. Sure enough the sharpest projected image measured at a backfocus position of 198 - 200mm (difficult to be too precise using this method.
I will be contacting Catalin at CFF tonight.