good evening everyone, I have some doubts and I hope someone can give me a hand, I have a skywatcher quattro 150 with its coma corrector all together with a QHY163C I don't use filters or anything else, what types of extensions do I need to solve the backfocus problem?
QHY163C backfocus
It will depend on the coma corrector. Let's assume that the coma corrector you use has a back focus of 55mm: the QHY163C already consumes 17.5mm so you would require another 37.5mm in extensions.
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