MT Shooter wrote:
Yes. All Tamron, Sigma, and Tokina crop sensor lenses mount just fine on all full frame cameras. Be they Canon, Nikon, Pentax, or Sony mounts.
The ONLY crop sensor lenses that can NOT be mounted on full frame cameras are the Canon EFS lenses. Canon intentionally cripples these lenses by adding a hard rubber extension to the rear of these lenses. Other than that crippling extension the EF and EFS lenses are exactly the same mount.
The rubber ring you talk about is not what prevents mounting an EF-S lens on full-frame body. It is in fact just a thin rubber cover over the rear lens element that protrudes out past the lens mounting flange. EF lenses do not protrude past the mounting flange. The thin rubber ring, easily removed by a fingernail, prevents two hard surfaces from bumping each other when inserting the lens in the body.
A crop body has clearance for the protrusion. A full frame body does not. That's why an EF-S lens won't fit on a full-frame body.
I too would love to know how an EF-S lens could be "hacked" to fit a full-frame body.