Tamron Working on an Internal Zoom 100-400mm f/5.6-7.1

[Canon Rumors]

Tamron is working on some fairly unique zoom lenses for full-frame sensors. While optical designs don't generally mention lens mounts, we cannot comment on any of these being future RF mount lenses.

Read The Full Article

 

[Exploreshootshare]

Sounds like Tamron reversed engineered Canons RF 100-400mm and found a way to make it slightly better (spec wise and on paper)