Tele-Elmarit-M 90mm f/2.8

Walter Mandler's tele-formula compressed the 90mm focal length into a lens barely larger than a standard 50. The original 1964 "fat" version gave way in 1974 to the "thin" Tele-Elmarit, one of the most pocketable telephotos ever made for a rangefinder and a travel-kit favorite to this day.

Buyers' note: thin versions are prone to internal haze — check glass before buying, and budget for a clean-and-lube on most examples.