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06-26-2010, 03:25 PM   #1
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FA 28-105mm F4-5.6 zoom question

This might have been asked several times but I've just got my FA 28-105mm F4-5.6, it has a motor zoom P & A->AS switch on the side whatever the letters mean, motor zoom works on my K-7, also switching to both modes makes no difference at all.

My question is whether I can zoom this lens as a regular "manual zoom" lens say like my 16-45mm, without motor interference. Also I like to know what the P & A->As means.


PS. I've read FA lens guide but it has no clue about this.

06-26-2010, 03:39 PM   #2
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The switch sets some of the camera based power zoom options such as zooming while the shutter is open, etc.

If you go onto the pentax site you can download the manuals for the lens, but they won;t help much unless yoou have a body that supports all the power zoom functions.

While pentax says the later (K series DSLRs) have a KAF2 mount, they do not support power zoom, except to provide power to the zoom motor

It's too bad because image size tracking was an interesting feature.
06-26-2010, 08:27 PM   #3
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From an FA Lens manual printed in 1991:

Last edited by clm; 06-26-2010 at 08:42 PM. Reason: added scans
06-27-2010, 10:50 AM   #4
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QuoteOriginally posted by clm Quote
From an FA Lens manual printed in 1991:
Thank you, obviously I've missed that, just pulled the ring and voila!, lens is a normal zoom again still don't know/understand the P - A-S means on the switch but they are for the older cameras I guess.


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