Originally posted by stevebrot
Adaptall is the earlier version of the mount while Adaptall-2 is the later version. I do not believe that the two are compatible either backwards or forwards. The Adaptall-2 mounts featured better compatibility with the various camera bodies. Before Adaptall came the Adapt-a-matic lenses. Same story here in regards to compatibility.
Steve
Actually, adaptall 2 mounts will work on Adaptall 2 SP and adaptall 2 lenses and will also work on the original adaptall lenses. Available features will depend on the lens and the adapter. If you want A settings, it will require at least an Adaptall 2 lens AND the PKA adapter. All lenses including the Adaptall, Adaptall 2 and Adaptall 2 SP lenses will work in the K mode with the PK adapter or the XR-P with the Ricoh pin removed.
Edit: In other words, if a lens is AE capable, it will need the PKA mount to do that. Otherwise, with the PK or XR-P mount, its just a K lens. I its a k lens, its a k lens know matter what mount is used. Well, unless you are using one of the 2 m42 screw mounts.
The Adaptamatic is a totally different ball game as is the T2 interchangeable mounts.