Have an old k-1000 35mm and it works great with my old manual lens on the Canon M series
14/10/2021
This is a very well made adapter that mates smoothly and firmly between my old Pentax K lenses and my new Canon M50. It is completely passive with no glass or electronics. My 50mm 2.0 never looked so good. Multiply your lens focal length (mm) by 1.6 to get the effective length on the M50 cropped sensor (50mm = 80mm). NOTE: To use on the M50, you must enable Release Shutter Without Lens AND turn off the Lens abberation correction (both Peripheral illum and Chromatic aberr). If you forget to disable the correction, an "err 70" may occurr if you use the focus zoom aid function (magnifying glass) and you'll need to remove the camera battery to reset it. I've since turned the corrections back on and the issue has not happened again.
13/10/2021