Canon's budget FD telephoto — the 135mm f/3.5 with S.C. coating for basic telephoto use.
The Canon FD 135mm f/3.5 SC is a budget telephoto prime for the Canon FD mount with Spectra Coating. At 135mm f/3.5, it provides basic telephoto reach at a modest aperture. The SC coating improves contrast over uncoated versions. One of Canon's most affordable FD telephoto options.
Optical performance is decent for a budget telephoto. Sharpness is respectable when stopped down. The SC coating provides good contrast. The f/3.5 is modest but adequate for casual telephoto in good light. The 135mm provides useful portrait compression and telephoto reach. Build quality is solid FD metal.
Canon FD mount, manual focus. Filter thread is 55mm. Weight is approximately 400 grams. Build quality is standard FD metal. The SC coating improves over uncoated versions. Adapts to mirrorless via FD adapters. The 135mm f/2 and f/2.8 versions are faster alternatives.
Very cheap. Check smooth focus. A basic FD telephoto at minimal cost. The f/2.5 and f/2 135mm FD versions are significantly better. Only of interest at very low prices. The SC coating is the only distinguishing feature over the cheapest alternatives.