Tamron Eyes Medium Format: New Patent Details Three Fast Primes With GFX Sensor Coverage
A newly uncovered Japanese patent publication from Tamron Co., Ltd. (特開2026-175043, published November 2, 2026) has surfaced, detailing four fast prime optical formulas—three of which feature large image circles designed to cover medium format (“large format”) sensors like the Fujifilm GFX system.
While Tamron has already become a staple third-party lens manufacturer for Fujifilm X-mount, the company has yet to officially step into the Fujifilm G-mount arena. However, the numerical embodiments inside this latest filing suggest Tamron’s optical engineers are actively researching fast-aperture medium format prime designs.
Patent Overview (JP 2026-175043)
- Applicant: Tamron Co., Ltd.
- Publication Number: JP 2026-175043 (特開2026-175043)
- Publication Date: November 2, 2026
- Title: Optical System, Imaging Apparatus, and Moving Body
- Core Objective: Simultaneously suppressing longitudinal and lateral chromatic aberrations in large-aperture prime lenses by optimizing refractive power distribution, Abbe numbers, and anomalous dispersion glass elements.
The Four Optical Embodiments
Within the patent documentation, Tamron outlines four distinct prime lens designs:
- Tamron 65mm f/1.8 (Medium Format / GFX Coverage): Features an image height (Y) tailored for 44x33mm sensors (~27.5mm–28mm). On a Fujifilm GFX body (0.79x crop factor), this provides a ~51mm full-frame equivalent field of view, slotting directly between the Fujinon GF 55mm f/1.7 R WR and GF 63mm f/2.8 R WR.
- Tamron 75mm f/1.8 (Medium Format / GFX Coverage): Also designed with a medium format image circle, delivering a ~59mm full-frame equivalent field of view on GFX—offering a fast standard-to-short-portrait focal length comparable to the GF 80mm f/1.7 R WR.
- Tamron 130mm f/2.6 (Medium Format / GFX Coverage): A dedicated medium format portrait telephoto prime providing a ~103mm full-frame equivalent field of view. It would sit slightly longer than the legendary Fujinon GF 110mm f/2 R LM WR while maintaining a more compact f/2.6 aperture footprint.
- (35mm Full-Frame Only): Unlike the other three embodiments, this ultra-fast portrait lens specifies a standard 21.63mm full-frame image height and would require 35mm crop mode on a GFX camera.
Will Tamron Enter the Fujifilm G-Mount?
For GFX shooters, third-party autofocus lens options have historically been much slimmer than on X-mount, though manufacturers have slowly begun testing the waters as the GFX100 II and GFX100S II expand the medium format user base.
Because these optical designs incorporate sufficient back focus distance to clear mirrorless medium format mounts (Fujifilm G-mount requires a 26.7mm flange focal distance, while Hasselblad XCD sits at 18.14mm), these formulas are clearly engineered with mirrorless medium format cameras in mind.
As always with Japanese optical patents, manufacturers frequently patent baseline optical formulas that never reach mass production. Still, seeing Tamron calculate three distinct 44x33mm prime lenses in a single filing is one of the strongest hints yet that third-party glass makers are keeping a close eye on Fujifilm’s Large Format ecosystem.
via jpat
