On Feb 27, 2007, at 9:28 AM, Adam Maas wrote: >>>>> ... The 67-645 adapter does provide >>>>> automatic diaphragm actuation and open aperture metering. At >>>>> least according to the Pentax literature. I'd love to buy one >>>>> of the >>>>> things if I could ever find one. >>>>> >>>> But will it offer open aperture metering on the 645D? >>> >>> Impossible to say without having a 645D to play with, don't you >>> think? >>> But I'd be surprised if it didn't. >> >> If the adapter provides the linkage then 645D should meter >> normally IMO. >> Pentax stated that 645D is compatible with all 645 lenses and the >> DFA55 is announced as being compatible with previous 645 bodies (and >> it has an aperture ring). >> >> So it should (hopefully) be OK. > > But all 645 lenses are A lenses, 67 lenses on an adaptor would be > effectively K lenses (Mechanical coupling but no electronic coupling). > It's quite possible the 645D will work just fine with actual 645 > lenses > and be stop-down with 67 lenses.
The 645 body has the mechanical aperture coupling lever. 645 lenses, taken off the "A" setting, allow full aperture metering. What you don't get when you switch to the aperture ring for control is Program mode or a readout of the aperture in the viewfinder, you do get the shutter speed and an indication of +/- EV from what the meter believes is the correct exposure. This is also true of using A series 645 lenses on the 645N and NII autofocus bodies. If the 6x7 to 645 lens mount adapter includes the mechanical couplings for auto iris operation and aperture ring position, they should work identically to A-series 645 lenses taken off the "A" position. If the 645D body supports the same things as the 645N/NII bodies, then all the lens and adapter combinations should work fine. G -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
