Tamron Adaptall Mount
Adaptall is a universal lens mount, developed by Tamron. On one side is attached to a special lens bayonet mount and the other side has a mount for the camera.
On photo above Tamron Adaptall lens without an adapter and with an adapter for M42 screw
Since 1975, Tamron has introduced a new standard for mounting its lenses, which replaced the Adapt-A-Matic mount. Since 1979, slightly improved design appeared Adaptall-2.
Adaptall – M42 mount adapter
Automatic aperture control mechanism on Adaptall – M42 adapter
What is the difference between Adaptall and Adaptall-2
Both are fully compatible and have the same construction. But Adaptall-2 differs from the first improved Adaptall reliability (so says the company Tamron). Practically check the reliability of these adapters are not opportunity.
Adaptall-2 – Nikon F adapter
Automatic aperture control mechanism on Adaptallo2 – Nikon F adapter
Compatible Adaptall with modern DSLR cameras
Adaptall and Adaptall-2 were produced for all kinds of cameras 70-80 s. Since then, many manufacturers have replaced bayonet mount and flange focal distance. Remain relevant only mount Nikon F and Pentax. For these cameras you can use the genuine adapter, a working automatic aperture control.
The rest of the mounts is no longer valid and can be used as intermediates. For example, you can use an adapter for M42 screw, which was popular at the time, and for which there is a set of adapters to the desired system. Thus we obtain the chain Adaptall-M42-our system. But you need to know that the automatic aperture control in such a chain will not work and the aperture will work like on old lenses without automatic control.
Alternate adapter Adaptall-2 – Canon EOS made in China
Also there are alternate adapters made in China, that can be done for a variety of systems and bayonets, but they also do not have the automatic aperture control.
But some Chinese adapters found defective, with poor or improper flange focal distance, whereby the lens will not reach to infinity. It is important to check before buying an instance.
Also this is Tamron Adaptall Lens System User Manual may someone it will be interesting.