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Hi Ian, and thanks for your reply..
It's already been fascinating, and I'm learning a lot...there are so many people on Ice In Space who are very generous with their knowledge and experience.
At this stage I don't think a custom mirror will be possible, so I'm thinking about alternatives....I've seen a couple of options at telescopes-astronomy.com.au that look interesting...
12" pyrex or BK7 at f/5
16" glass at f/5
I'm 180 cm tall so the 16" f/5 focal length of 200cm might put the eyepiece a bit high. 16" at f4.5 (f/l 180cm) might just be possible though...
These mirrors are stated to have strehl rating of better than 0.88 and wave rating of 1/8. I'm wondering how these figures stack up - trying to find out what the minimum numbers are for "very good but not premium" optics.
As I work towards a more definite idea of what I'm looking for I'm going to keep my eyes open for something second-hand as well, as this might be the most cost-effective way to go.
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