On Tue, Feb 19, 2013 at 9:26 AM, <erikhansen@thebluezone.net> wrote:
One year at Riverside I met a person with bino's made with 2 jeagers 6" f5, as I recall he asked the supplier to make sure the eyepieces they sold him matched in focal length.
Eyepiece focal lengths are typically close enough if done in the same production batch. Small lenses are typically ground and polished in groups on a common mandrel. Lenses have spherical surfaces so figuring is not usually necessary (there are exceptions, such as certain camera lenses). Remember the 2% Mil spec for final magnification. You know, if you had slightly mis-matched eyepieces, you could arrange them so as to compensate for a slight mis-match between objectives. It could actually work to your advantage.