Thinking of something narrower: Panasonic 42.5 F/1.7, Olympus 45mm F/1.8 or Sigma 30mm F/2.8

Hithertoo wrote:

If I got an EF adapter I have a bunch of lenses that I can borrow. I would suspect the issue with the EF adapter is the slow AF speed. People say the Panasonic 20mm F/1.7 is slow because of its focus motor, and it is to a point, but on top of the fact that EF lenses generally require a PDAF sensor (excepting the EOS M), most Canon lenses have the same sort of focus motor as the Panasonic 20mm F/1.7. That is slow and noisy screw drive lenses.

It's an interesting prospect but I would have to at least own an E-M1 first and then I may think twice about it. Adapted lenses no matter on the format including Sony E mount (where there are numerous AF adapters) or Canon EF mount, are always slower than what they would be on a native camera.

The Canon 40 2.8 STM at least is NOT slow to focus....not on my CDAF GX7 anyway.....it is pretty much native in focus speed.

It did have a lot of distortion before the firmware update but is fine now.

In low light it is a bit slower but not really any more than many native lens.

Still works fairly well in low light with a GX7 (EV -4 AF is ok).....which is also much better I think since the firmware update.

One thing that is still a small issue is it keeps trying to focus when not being used so will drain the battery if not turned off when not using it.

Touch AF and touch shutter work great with the 40 and the Kipon (as does he 135 f2 L Canon too).