Quote:
Originally Posted by LewisM
Yes John, 52° AFOV. Simply superb EP in refractors (didn't like it in the Mak that much).
I checked Astromart for some recently, and couldn't believe the current second hand price for them...$300 to $400 US - and they sell.
|
Hi Lewis,
I suspected as much. I have used the 52 deg AFOV ones down to F5 in Newtonians and they work very well. Due to the optical design limitations with 5 lens elements, it's not possible to get the 85 deg AFOV versions to perform well in fast telescopes. They will be excellent performers in slower scopes. They may or may not work well in SCT's which notwithstanding their F10 overall F-Ratio, generally have primary F-Ratios of F2 to F2.5, as some aberrations like field curvature are related to the F-ratio of the primary optic and not the F-ratio of the telescope.
Cheers
John B