Originally posted by newarts I made an easy, reversible modification of my camera's mount so it thinks all lenses are "A" type. This lets P-TTL flash work properly with all lenses and allows me to set the proper lens f-number to be recorded in EXIF (adjusting the viewfinder's report of f-number has no effect on an m42 lens). I have found no downside to this mod.
I've seen this before and finally decided to try it on my K20D. Implementation isn't quite as simple as purported: getting the ring|plate straight up is slightly tricky, and when replacing it, be sure to get the lens-lock pin in its hole first. But I managed to avoid losing screws, and it's back together and functioning.
Results... I'm not sure what to expect. So far I've just tried some test shots with K, M, A, M42, T2, and N/AI (modded) lenses. The camera does think the K and M glass are A-type. It doesn't recognize the others, even though the bases short all other mount pins. Onboard pTTL flash *does* work but not very well, and metering is way off in all modes.
Conclusion: I don't really see this as useful, not for me anyway. I'm going to pull the foil.