PAL markings ...auto blockers

[idispense]

Some auto blockers have the ability rotate a lens to the correct axis setting automatically after you 'toss' the lens onto the chuck table.

How do they accomplish this ?

How does it work with PAL lenses ? How does it identify the layout markings for the seg height and optical centers ?

[RT]

On PAL's, autoblockers locate the 34mm alignment reference marks, which indicate the location of the Prism Reference Point (PRP).

[idispense]

On PAL's, autoblockers locate the 34mm alignment reference marks, which indicate the location of the Prism Reference Point (PRP).

Yes thats true , but the question was: How do they do that ?

[Dave Metzger]

The camera locates the 34 mm marks. Sometimes you need to enhance them with a white out pen or other marker that the camera can recognize. You also need to input the mrp of 2, 4, or 6 mm. Forgot 0 for Seiko