Canon's modest FD telephoto — the basic 100mm f/4 for the FD mount system.
The Canon FD 100mm f/4 is a basic compact telephoto prime for the Canon FD mount. At f/4, it provides a modest aperture at the short telephoto focal length. One of the more basic telephoto options in the FD system — the 100mm f/2.8 and 85mm f/1.8 are more popular for portrait and telephoto work.
Optical performance is adequate. Sharpness is acceptable when stopped down. The f/4 maximum aperture limits DOF control and low-light capability. The 100mm provides a classic short telephoto perspective. Build quality is typical Canon FD metal construction. Not a standout performer — a basic functional telephoto.
Canon FD mount, manual focus. Filter thread is 52mm — compact. Weight is approximately 285 grams — lightweight. Build quality is basic FD metal. The compact size and light weight are the main practical advantages. Adapts to mirrorless via FD adapters.
Very cheap. Not recommended when the f/2.8 Macro or other FD telephoto options are available at similar prices. Only of interest at essentially zero cost. The compact size is the sole distinguishing feature.