Hi, this adapter is for Canon EOS mount lens to Sony E NEX mount camera, we checked the sony a 7iii camera mount is E mount , this adapter can fit it , but you can reconfirme it , thanks.  

Dear Customer, this tripod could be compatible with your sony 4k fdr-ax53 camcorder. and other devices could also be used on it as long as it has 1/4 screw mount. 

Yes, it will fit any Sony e mount body, either full frame (a7..., a9...), or aps-c (like a6500, etc) 

yes, i had no problems with infinity focus with this adapter. the only FD mount lens i use anymore with my sony is a vivitar 20mm, and i pretty much only shoot infinity focus with it. 

Yes it should work with the sony a6000. As long as the ka lens has an aperture ring on the lens and is not solely dependent on receiving aperture control from the body, this adapter should work fine with ka lenses. To my knowledge, there are no sony e mount to k mount adapters with electronic coupling so no lens control through the body (meaning aperture and focus are fully manual).