Originally posted by pearsaab i was playing around yesterday with a Tair-11A 135mm f2.8 M42 screw mount with a pentax screwmount adapter to the q-k adapter on the q...i was using the av setting on the adapter but was curious would the f setting have any impact on the pictures.
AFAIK, the aperture setting on the adapter (1, 2, etc.)
should only set the aperture on a mounted A-type lens
with its aperture ring at its "A" setting
(or a DA lens, which doesn't have an aperture ring anyway).
So with an adapted M42 lens, you'd be best to have the K2Q adapter
at its "L" setting (meaning aperture controlled directly by the ring on the lens).
Then make sure the M42 lens is not set for "Auto" (if it even has that setting),
so the aperture ring on the lens directly stops down the iris.
(But you may want to have the lens opened up for focusing.)