|
The shorter focal length eyepieces: 20mm, 15mm etc are 1 1/4", because there is no advantage to making a 2" in this focal length. You wont get any more light in because at these focal lengths the field stop is smaller than the maximum aperture of a 1 1/4", let alone a 2" (unless you go for an 82 degree or above apparent field like a Nagler of Ethos: and even these are 1 1/4" for any focal length below 17mm).
So have no fear in buying the 20mm and below Superviews!
|