> My FG-20 has a strange lever inside the camera, just behind the lens > monting. (At 9 o'clock tehere is the auto aperture coupling lever, I > know it well) There's another one. Situated at half past 5 and moving > back to 5 o'clock. Some lenses have an immobile lever just coupling with > it, some don't. I haven't figured out its function. Peeter, AI, AIS and all AF lenses have the tab you mention, next to the rear element. This is the lens speed post, and tells suitably equiped cameras how fast the lens is. The camera uses the absolute lens speed info for pogram modes, and to enable matrix metering (FA and F4). Most AF cameras don't use this system, lens speed info can be transmitted much more accurately via the electronic contacts. Roland
