Hi Allan,
Thanks for the inputs. Let's hope we can eventually come up with a set of reliable numbers! It would be nice if others also donated any info on other types of FR's that are known.
Small comment on the Meade info, the default Meade FL from the Timo calc is 260mm, and shows a FR of .67 at 87mm, needs 95mm to achieve .63. No big deal.
Also note comment from
http://www.wilmslowastro.com/software/formulae.htm about much shorter FL of post 2006 Meade .63's. Just trying to verify that comment, would you consider your Meade to be pre 2006? I have one of unknown vintage, so will have to suck it and see.
I used 154mm FL (post 2006) as was mentioned as the FL in the other link to get the 57 at .63FR for a Meade. Would be good clarify this for newer post 2006 Meades.
Let's hope we can build on the list, now that there are some easy to use tools to do it.
I put my C8 on the mount yesterday, so will play around this week and post my results.
Cheers,