The Mamiya RB67 37mm f/4.5 Fisheye is an ultra-wide fisheye lens for the Mamiya RB67 medium format SLR system, providing a circular or near-circular image projection on the 6x7 frame. Designed for architectural, landscape and creative work where extreme angle of view is required, it pairs with the RB67's bellows focusing body and leaf-shutter mount.

Hammer prices for the 37mm Fisheye are scarce at saleroom level, with one verified UK auction result at £688 in January 2024 setting the only firm reference point we have today in 2026. With so little turnover, that figure should be read as a single data point rather than a true median, and clean, fungus-free copies with the original hood and caps can plausibly sell for more when they do appear. Buyers asking what a Mamiya RB67 37mm Fisheye is worth should weigh condition heavily, since cosmetic and optical faults move the value sharply.