Sigma 400mm f/5.6 MC Manual Focus Breech Lock Lens for Canon FD-Mount, Gray Review

The Sigma 400mm f/5.6 MC is a legacy manual focus telephoto lens built for Canon's discontinued FD breech-lock mount. Originally priced around $85 on the used market, it represents an affordable entry point into long focal length photography for those who still shoot film or adapt vintage glass to mirrorless bodies. The f/5.6 maximum aperture and 72mm filter thread are typical for manual telephoto lenses of this era.

This is a used, film-era optic that requires manual focus and exposure control. It will not mount on modern Canon EF or RF cameras without an adapter, and even then you lose any electronic communication. The FD mount is primarily of interest to collectors, analog shooters, or those experimenting with adapted legacy glass. If you have a compatible Canon FD film camera or a mirrorless body with the right adapter, this lens can deliver usable telephoto reach at a low cost. Build quality and optical performance vary by copy condition, so inspect carefully before purchase.