I'm using on the adapter Canon FD 50mm f / 1.4 SSC On the camera side of the adapter is firmly seated. But the Objekttiv wobbles (in 1/10 mm range I guess). When I ask to infinity and the lens of the camera pull away, then sichbar what is not in the infinite in the display Focus Peaking. Now I do not Think me as I can because what terminals between the the lens can pull away. Then I'd be satisfied. For the price I Allerding already expected that the adapter may not be 100% safe.