Thread: [NOT REQUIRED] 12"-ish, f/7-ish primary mirror.
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Old 14-07-2019, 09:24 PM
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Bobbyoutback
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Join Date: Oct 2009
Location: Broken Hill
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Wave specs

Quote:
Originally Posted by mental4astro View Post
Surface specs 1/8 wave or better.

Cheers

Alex.
Hi again Alex ,
That 1/8 surface spec could be interpreted as 1/4 wavefront giving a Strehl ratio of .82 or the Rayleigh limit , not a top mirror .

Now is saying that I might be getting it wrong' but Id'e be be looking for a .92 or above Sterhl ratio mirror .

Have heard a perfect 1.0 Strehl mirror is not possible .

Regards
Bobby.