Sigma Mount Converter MC-11

I have tested this device with the following lenses: - sigma 35 1.4: smooth and reliable AF - sigma 15 f2.8: no AF, but MF - canon 16-35 f4L: very smooth and reliable AF - canon 50 1.8 II: smooth and reliable AF - tamron 15-30 f2.8 vc: very smooth and reliable AF - Canon 70-200 f2.8L IS II: very smooth and reliable AF - Canon 85 f1.8: smooth and reliable AF No lens is ok for filming with AF. The lenses will hunt like crazy while constantly searching for focus. At MF there are of course no problems. Even in darker conditions (twilight) the AF will still work relatively well, but the accuracy deteriorates. In even darker conditions, the AF irrevocably deteriorates severely. Build Quality: Feels a bit light and cheap, but is still strong enough and gives just enough luxury to get to work with confidence. It can take a beating, but I don't think it will take a 'punch'. Image quality: I haven't noticed any differences yet. Everything seems to give the same sharpness as on my canon bodies, with 1 big difference: pack more Dynamic range! Of course this is because of the sony body and not because of the sigma converter. On the other hand, nothing noticed. I can certainly recommend the product. After a few months of use on an A7II I am definitely satisfied with it. In the future I will certainly purchase the A9 or if it comes: an A7RIII. One thing is for sure, the newer the bodies and the more advanced their AF system, the better the mc11 will work. I see a bright future for this converter. Don't forget: the device can be updated via USB! This means it will continue to work with all newly released sigma art and other lenses.