The pictured lens belongs to a gentleman who wishes to list it on ebay.
I’m trying to help him get his listing correct so the buyer gets what he/she is expecting.
I’m hoping someone here has the same lens and can compare the measurements of the physical size of the lens.
An ad for the lenses lists two stereoscopic versions (6.5” and 9” FL) and four single sizes (10”, 12”, 15”, and 20”)
Here are the other measurements he gave me:
1. Diameter of the glass in back: 2 1/8”
2. Diameter of the front openig: 1”
3. Outside diameter of the mounting flange: 4”
4. Length from the back of the lens to the front: 3 ½”
He “guesstimates” the focal length to be 17” … but I also told him to measure the FL of a 19” Artar that came with this one and he came up with 21” using a ruler and focusing outside through a window. So, if he’s off about the same amount on the pillbox, it is probably the 15” one. On the other hand, I think he measured to the back of the lens, and if the FL on these were measured from the washer aperture in the front, it might be the 20”.
Anybody got one of these and can solve this for him???