Quote:
Originally Posted by Ridgback
Dob with paraboloidal pyrex mirror
and
Dob (collapsible truss) with a parabolic mirror
Both have spec's 254mm, 1200 focal length (f/5 or f/4.7)
So with almost identical spec's from the same manufacturer I still do not understand the difference between "paraboloid" and "parabolic".
If anyone can explain how they have different f/ratio with the same aperture and focal length I would appreciate it as the published concensus seems to be :focal ratio = focal length of telescope / aperture of telescope
Dale
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Hi Dale,
same horse
, just different ways of describing it.
