Does not set focal length in the IBIS system on Sony cameras. It sets it OK in the metadata so it reports 75mm in the finder and the file, but in order to get IBIS to function on Sony cameras, the focal length must be set manually in from the menu.Menu:Shooting Image StabilizationSteadyShot Adjust ManualFocal Length 75mmViltrox customer service told me that this is Known to engineering about about Aug 31, 2023.All the other good things said about this lens I agree with. I shoot a lot in very low light, so I noticed I was getting motion blur when normally would not.

this lens is amazing! one of the sharpest lens i have ever owed. I would recommend this lens to pros and newbies. If you dont get great files from this lens, photography is not for you.

Autofocus on the Sony 6600 is fast and accurate and, while not totally silent, it is very quiet. The aperture ring has click stops which can be switched off but the detents are weak so will probably not totally prevent inadvertent changing of the aperture. Whether clicks are on or off, the A setting is firm and not likely to be accidentally bumped. The included petal shaped hood also bayonets and clicks into place but that click is a bit weak as well. Manual focus works smoothly and precisely. I have the custom button set to allow moving/locking the focusing point which is a nice convenience on the 6600 which lacks a joystick. The lens is weather sealed and uses 77mm filters. I expect this to be a great portrait lens on the 6600 with a full frame equivalent of ... MoreAutofocus on the Sony 6600 is fast and accurate and, while not totally silent, it is very quiet. The aperture ring has click stops which can be switched off but the detents are weak so will probably not totally prevent inadvertent changing of the aperture. Whether clicks are on or off, the A setting is firm and not likely to be accidentally bumped. The included petal shaped hood also bayonets and clicks into place but that click is a bit weak as well. Manual focus works smoothly and precisely. I have the custom button set to allow moving/locking the focusing point which is a nice convenience on the 6600 which lacks a joystick. The lens is weather sealed and uses 77mm filters. I expect this to be a great portrait lens on the 6600 with a full frame equivalent of 112mm. It might even work well for indoor sports but I haven't tested that yet.This lens is apparently all about the glass. Testing shows the lens to be amazingly sharp over the entire frame from wide open to 8. Slightly weaker at 11 and soft at 16. At 1.2 even corner sharpness is incredible.This is really a great bargain. It's available for Sony, Nikon and Fujifilm - but not Canon.The lens looks and feels very well made but not in the same league as a Sony GM lens. On the other hand, it is opticallycomparable to much of my Sony glass. Meanwhile, it costs 73% less than a Sony 85mm 1.4 GM.