Throughout the life of the Edmund catalog up until around 1976 you could buy "High Quality Refractor Objectives" mounted in a cell or unmounted. The 3"f/15 and 4"f/15 are the same as what came on the 3 and 4 inch refractors.
And then we have the 5 inch lens, with it's different cell and a focal ratio of 14.2, and Edmund didn't make a finished 5 inch telescope.
This 5 inch lens is lumped in with the 3 and 4 lenses in the catalog just like it was a member of the family.
Does anyone know anything about the Edmund 5"f/14 lens?
Rather than the steel cell with screw in retainer ring the 5 has a cast aluminum cell with 3 blocks to
retain the lenses.
The blocks each have a single machine screw to hold them, and the cell also has a
flange with collimation screws.
Edited by actionhac, 05 December 2015 - 01:39 PM.