There is a lot of confusion on the performance difference between lenses if used on a specific camera body, especially with regards to using full frame lenses on crop sensor cameras (like the Sony a6000, my camera, which uses a “crop” APS-C sensor).
Cameras like mine take lenses designed for crop sensors (naturally), but also take lenses that are rated for full frame cameras (like the Sony a7iii).
The confusion comes in to play in what kind of image these two lenses will produce at comparable focal lengths, as the discussion of camera “crop factors” is often used interchangebly with lenses as much as they are for sensors. Even I have to admit being messed up on it for quite some time (hence this post).
If comparing a full frame rated lens with a crop sensor lens on the same crop sensor camera body, the main difference is this: nothing.