I think we convince ourselves that we need those "tack sharp" stars to the edge without considering the job our brains do at integrating the image. I would consider carefully whether you really need the Paracorr, which is expensive, very heavy and awkward, and extra glass. Even at f/4.3. Perhaps this is heresy, but the wide fields available these days are wider than you real can focus on, so that the periphery provides "context," but not detail. The brain fills things in...Originally Posted by FaithJ
I have a f/4.2 18" with which I use 8mm/13mm/and 21mm Ethos. I use a Paracorr on the 8 & 13 only because it balances them with the 21mm and brings them closer to parfocal. I don't use the Paracorr with the 21mm because then I don't have enough inward focus and I don't want to cut my tubes. Nor do I feel the loss, at least with the 100ยบ FOV.
If the Deloi function like the Ethoi, but with the smaller FOV, I'd say they were well worth saving up for. I'm afraid I hardly every use my Naglers anymore.
Kemer
Obsession 18" UC f/4.2
Please, God, give us some clear, dark skies to use it!
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