Hi from a newbie, Searched on this and haven't found much in the way of information. I have a some Pentax-M lens left from my Pentax MX system. I bought a K10D + a few lens and have never found the Pentax M easy to use on K10D. I have been considering changing systems. I am thinking about a few more lens to fill gaps and then there would be an upgrade to a K5 sometimes which given the cost of lens is a fairly hefty sum. Also the K10D works better with Pentax A lens due to changes in the way the aperture ring was indexed. I understand that I can use Pentax M lens vias an adaptor, but am unsure how the metering is done. I assume it would work in stop down mode and work with both manual aperture priority exposure modes. Hopefully someone can clarify.