90mm Projector Lens Group Test
Most makers of 35mm slide projectors offered a bread-and-butter plastic-barrel 85/2.8 and an optically superior upgrade that could be specified at purchase or retro-fitted. These lenses typically (though not always) jumped to 90mm but were always a little faster: commonly f2.4 or f2.5. The glass wasn’t just longer, it was deeper: deluxe options eschewed triplets …