once bought a €5 adapter to test the lenses. It worked well. That works well too, but the build quality makes it look like it's part of the camera itself. Very sturdy and feels good. In love with him. IMPORTANT: If you are super picky and take pictures of very far away objects (e.g. moon) and need absolute precision, this adapter (same as any adapter on the market) will only focus infinitely _exactly. It appears to be designed with about 0.5mm more flange, and at maximum aperture (perhaps for astrophotography) it falls behind just a bit. Perhaps removing the ring mount and sanding it a little (is 1mm thick) could help achieve perfect infinity focus. Another possibility is to stay at f8~f11 and then tend to get decent focus at infinity (tested at focal focal points 50~200mm). Quick test, focus seems off by 0.5mm max (I removed the 1mm ring, tested on my hand and it focuses to infinity). This also seems to match the flange difference needed: Canon FD = 42mm; Sony E = 18mm; flange difference = 24 mm; Adapter thickness (from E base, not bayonet, to Canon FD bayonet) = seems very like 24.5mm. So you know Great adapter, just grind the ring mount down a bit.