Quote Originally Posted by 1manilaboy
Can anyone shed some light on this problem I am having. Just received a +2 diopter (without instructions) cannot figure out where it goes in the eyepiece, in front of or behind the lens that is already in there?
thanks loads,Rene
The term "diopter" actually is a measure of lens curvature. It has come to mean, generally, a lens inserted into the viewing system to correct for vision anomalies. Chances are (~75% or so) it replaces the "standard" eyepiece lens - the one nearest the eye of the observer. In the Hasselblad prism, the "standard" eyepiece lens is removed - right hand thread - and the replacement screwed in.

Depending, though - it may be an auxiliary lens that fits over the existing eyepiece lens.

Careful, too - some of the so-called "Portrait" or "Close-Up" lenses are labeled in "diopters".

What are the physical dimensions of this puppy?