Originally posted by wilkin how come you want this lens in manual only?
Without the fix, the M42 lens is at wide open aperture and there is no mechanics in the K10/20/100/200 KAF mount bodies to depress the pin. I don't know how to say it correctly, but a modification is needed for the lens to work in all apertures
There are many Auto M42 lens that have the A/M switch for auto and manual. For those M42 lens, you want to switch to M for manual diaphragm so that the aperture is governed by what you set on the aperture ring. But there are older M42 lens such as mine in the picture that don't have the A/M switch.
Thanks,
Hin