I have just got a Pentax Me Super from ebay and started to try some M42 lenses I got earlier. With M42 to Pentax K adapters, I am able to put old M42 lenses on my Me super. However, there is an annoying problem of metering shift. Based on tests I have done, the problem seems to be from the adapters.

I have two adapters, both are third party. One of them, which has no flange, makes the metering constantly 2 stops under correct exposure, and the othere, which has a flange, makes correct metering. They are tested with the same lens. Therefore, I come to realised that it is the adapters that are really making the problem. I wonder if anyone of you have encountered similar problem. Is this normal? Will a genuine adapter from Pentax solve the problem?

Please help. Many thanks!

Pei