0.72x Focal Reducer Speed Booster Adapter for M42 mount lens to Canon EOS M EF-M mount camera - M5 II M50 M100
0.72x optical glass lens adapter for using Canon EOS M EF-M mount APS-C digital cameras with M42 mount (42mm x 1.0) lenses.
(Optional M39-M42 adapter ring for M39 lens)
Reduces focal length to 0.72, adjust the image size to near 1:1, so that the focal length of the image is close to actual focal length of the lens, e.g. 50mm x 1.5 x 0.72 = 54mm.
Helps to increase the maximum aperture to 1 stop, also can use it faster by 1 stop.
Switching camera to "Release shutter without lens" in custom menu C.Fn7 is essential.
Allows focus infinity.
Blue spot will occur if lens is shot to sunlight or lamp directly.
With front and rear caps.