K100D & K10D, shake reduction and 'foreign' optics.

Started Sep 13, 2006 | Discussions thread
Roland Mabo
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Re: K100D & K10D, shake reduction and 'foreign' optics.
In reply to distudio, Sep 13, 2006

The manual focus A serie lenses (KA mount) doesn't contain the electronic chip that KAF lenses does! A lenses can only transmit the widest aperture to the camera, that's all they do. With the introduction of the KAF mount in 1987, Pentax also introduced focal length, distance information and other neat things. This information is given by any lens compatible with Pentax KAF mount. The third party makers KAF mount lenses must provide this information, otherwise they wouldn't work on Pentax AF bodies! The reason for the lenses to give the focal length to the camera is that Pentax patented multsegment metering uses the focal length information when it calculates the exposure! The focal length information is also used by the flash autozoom. Yes, when I put my 10 years old AF330FTZ flash on my camera, it autozooms to the focal length choosen by me on the lens. When I use a zoom, the flash autozoom to the choosen focal length. It works with all KAF compatible lenses, like the Tokina AF 28-105 f/3.5-4.5 AL I had for a couple of years before I replace it with the FA 28-105 f/3.2-4.5.

This is a silly discussion...

Take care
R

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