I have to modify my previous statement :
this will work only with m42 lenses and some PK-M lenses...
Richard64 : As stated by Lowell, the A pin is recessed, and thus is not shortened by the lens...
You have to cheat to ground it: I carefully applied solder on this A pin, without heating it (as it would certainly damage the mount), but you can do it in a less permanent way by adding some conductive adhesive or even an aluminium foil...
As for P-TTL and Matrix metering, I confirm that once the A pin is grounded, both are really working : the flash works properly (preflash and all) at any selected aperture, and
wireless is again available!
It's a little bit more difficult to check the matrix metering function, but at least it's displayed in the review mode of my pics, instead of the CW metering icon...
Now, theorically, they both need additionnal information from the lens (focal length, etc) to perform fully, but I didn't find any flaw in the pics I took... After all, I'm not sure that all PKA lenses are fitted with the data pin to send these information to the body.
Now, regarding my comments about selecting the smallest aperture, it was not about flash anymore, but rather a general comment on how this mod will transform
some PK-M lenses into PK-A.
I stress the "
some" part of this statement! As Lowell already said, not all PK-M lenses (and, I guess, nearly none, in fact!) are capable of this.
As stated, PK-A lenses have a surface-related lever movement, and PK-M lenses
usually have a diameter-related lever movement.
But I've found that some PK-M lenses have this capability... For instance, I have a gorgeous Porst 55mm f/1.2 that can be driven this way right up to f/11, then start overexposing as the lever won't close it enough anymore (I don't care, I'm in portraits anyway!)...
I think that only 3rd party lenses can be expected to work this way, as they usually were made to work with other mounts already working with surface-related coupling.
You just have to try (good thing is that with an aluminium foil, it's quite easy to do!)...
Last edited by dlacouture; 12-11-2008 at 08:35 AM.