Frank ([EMAIL PROTECTED]) asks:
<< Anybody understand how the AF 1.7 adapter works? >>
You put any K or A series lens on the adapter and set the lens at infinity.
Put the adapter on your autofocus camera.
The adapter mechanically moves a small internal lens in/out to get focus.
It uses the autofocus screw mechanism of your camera,
along with the electronics to get the focus right.
Focal length of the lens used moves up 1.7X (100mm becomes 170mm) and you
loose light/speed. The minimum aperture moves up 1.7X (f 2.8 becomes f 4.76).
You can put an autofocus lens on the setup, but it will not use it's internal
focusing mechanism, rather it will move the adapter's lens in/out to achieve
focus.
You can mount the adapter on a non-autofocus camera, but focus is a problem.
Wherever the adapter's lens was last left is what you start with. You may or
may not be able to get your Lens to focus at the distance you need because of
where the internal lens is set. (You can adjust this, but it is rather
impractical for operation on a non-autofocus camera.)
Regards, Bob S.
-
This message is from the Pentax-Discuss Mail List. To unsubscribe,
go to http://www.pdml.net and follow the directions. Don't forget to
visit the Pentax Users' Gallery at http://pug.komkon.org .
