The Canon E 50mm f/3.5 is an enlarging lens rather than a taking lens, designed for use on a darkroom enlarger to project negatives onto photographic paper. It is a specialty optic from Canon's wider photographic accessory line.

Auction data for this lens is extremely thin: a single UK saleroom result from February 2024 saw one example sell for £5 at hammer. On that basis the lens currently sits at the bottom of the darkroom-accessory market in 2026, and any value beyond a few pounds would need to be established by further sales evidence.