The Viltrox Mount Adapter NF-E1 lets you use many Nikon F-mount autofocus lenses on many Sony E-Mount cameras. “Many” is doing a lot of work here, so it’s best to check over the compatibility list at this link. With supported cameras and lenses, function is very good: autofocus is not as quick as with native Sony lenses, but it’s pretty decent, and autodiaphragm operation is preserved. For an adapter doing something that was never meant to happen, it does a pretty impressive job.