Canon's modest FD telephoto — the basic 100mm f/4 for the FD mount system.
The Canon FD 100mm f/4 is a macro prime from Canon's FD film SLR lens range, providing 1:2 macro magnification with the camera body directly and 1:1 with the Canon Life-Size Converter FD accessory. The f/4 maximum aperture is slower than the f/2.8 sibling, making it more compact and affordable.
The lens delivers 100mm at f/4 maximum aperture with 1:2 native macro capability, Canon FD bayonet mount, fully manual focus and aperture operation, and Canon's standard FD coating. It is a dedicated macro prime well suited to close-up subjects at the 100mm working distance.
The FD 100mm f/4 macro is smaller and lighter than the f/2.8 SSC version while sharing the same 100mm macro focal length advantage. It is popular for adaptation to Sony E, MFT, and Fujifilm X mirrorless mounts where FD adapters are widely available. The f/4 maximum aperture limits low-light use but is adequate for macro work where small apertures are often preferred for depth of field.
Check aperture blades for oil contamination. Test focus ring for smooth travel from minimum macro distance to infinity. Verify FD bayonet coupling engagement. Inspect element surfaces for haze, fungal spotting, or coating damage. Test macro performance at 1:2 magnification for sharpness and flat-field correction.