CANON FD 135mm F/2.5 S.C. MF Zoom LensS/N:6443547275 135 mm f/2.5: introduced in 1971 as one of the first lenses in the new Canon FD mount. Like all of the very early Canon FD lenses, it does not indicate the type of coating on the front lens ring. All lenses from 1971 (indeed, from the very early 1950s forward) were coated in one form or another.[1] 135 mm f/2.5 S.C.: The marking for Spectra Coating (SC) was added in 1973.