> William Robb wrote: > > When the lens is off A, the electrical contacts are disabled, and the > > lens has no electrical communication at all with the camera. > > It's not just AF cameras. The Super Program is the same way. >
This is right only for A-lenses. When the aperture ring is set off A the "A-contact" retracts and the contacts seem to be disabled . John Francis wrote: > But that's because they communicate this information via the digital > readout pin, not via the mechanical aperture coupler. Apart from this 7th digital read-out pin there is another difference between A and F/FA lenses. The "A" contact of the F/FA lenses does not retract when the aperture ring is set off A. So all contacts seem to remain connected even when the lens is set not to A. Interestingly, as far as I remember, also with F/FA lenses the SFX does not show the aperture number on its display when the lens is off A , while newer cameras do. Alexander __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
