Autofocus ran from control behavior (albeit more slowly than in the DSLR - see review for EOS M himself), very evenly without Nachregelvorgänge and silently only when Canon EOS M 18-55 kit lens from STM. After that, the 24-105mm L lens that is not quite as precise and underwent showed little ringing followed. The 40mm STM was a ticking restless. Quite loud was the EF 50mm 1.8, which is the best lens with a rather simple mechanics, but makes very sharp images. After it had correctly focused, tried unnecessarily after a few seconds the focus to improve again, so that the image was blurred again briefly, and then sharp. This was observed at irregular intervals several times. In particular, the films are Nachregelvorgänge during AF, especially if they make the image blurry short, useless.
Practically, even includes a detachable foot bottom of the adapter, where you can screw on the tripod because the very small and lightweight EOS M is top-heavy in relation to many Canon EF lenses, especially with telephoto lenses. So the EOS M sits perfectly fixed on the tripod. One can thus also easily open the bottom lid, without having to take the EOS M from the tripod when there wants to change the battery or SD card.
Since the quality 18 Megapixel APS-C sensor only really reached the maximum image quality with high-quality Canon EF lenses, you should treat yourself this adapter!
