Re: [APML] Pelican mosaic plus NGC 6559

["Bobby Middleton" <bobm@koyote.com>]

From: John C. Mirtle <mirtle.j@home.com>

> Excellent stuff, once again Bobby! it must be a ton of work to create
these
> images though. Is large format something you are looking into for the big
> newt? It could save you a ton of time, but it would also introduce
problems
> with vignetting and coma. Just wondering if you have ever looked in to
this.

Thanks John.
To do med format with the 12.5" I'd need a field flattner. If I'm not good
and square with my optical path I already get some long stars on 2 corners
just with 35mm. Plus I'd also have a vignetting problem with my 2" focuser.
But it's something I have thought about and looked into. I have a 2.7"
focuser plus a 2.7" OAG.  I'd have to get a FF designed and built. But how
much could I gain with all that effort? According to newt 2.5 I could get up
to a 1.88" 100% illumination circle. But's that's just according to "the
book", right?
Bobby


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