Yep!
But there'are some rules of thumb here (C-mount on m4/3):
-the more FL the less vignetting
-usually acceptable FL range starts from 25 mm +; everything down 25mm will give You circular sub-frame image on standard m4/3 frame (exceptions are subframe sensors/sensor modes like Black Magic Pocket Camera or some Panasonic crop video modes)
-25 mm is on the edge, depending on the size of the sensor they were originally desinged; in most cases some black vignetting in the very corners, but there are some old TV/film lenses of this FL that can cover the whole m4/3 frame.
Regards,
-J.