Originally posted by CristiC is that pin OK ?
That would be one possible source of the problem.
, but not one traceable to the adapter. It is possible that the brand-X adapter has bent or jammed the aperture follower tab that is recessed at the top part of the mount. Edit: While damage such as I noted in the struck out text might be possible, it would affect the metered shutter speed on the ME Super, not aperture. End edit.
For the OP...Describe more fully what you mean by only metering at smallest aperture.
Lens always stopped down?
- or -
Lens meters wide open, but always stops down fully regardless of the amount of light aperture ring setting?
BTW...Welcome to the Pentax Forums!
Steve