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Old 05-06-2018, 09:52 PM
Wavytone
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Wavytone is offline
 
Join Date: Jul 2008
Location: Killara, Sydney
Posts: 4,147
Quote:
Originally Posted by gregbradley View Post
Guaranteed better than .95 strehl.
The triplet APO's 100-130 mm seems to be a sweet spot for sure, and at a stretch to 140, maybe 150mm great... but... beyond that they're impossible in terms of size, weight, the mounting required and sheer cost.

OTOH no such thing as a 9" refractor that is reasonably portable in a small car. But a 9" mak does (or dob or SCT), and this one is 0.965 strehl, for a fraction of the price of an equivalent refractor.
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