[penG]

Looking intently at purchase of the KP but don't know much of anything about the Pentax line. On the KP web page under compatible lens they list this, "KAF2 (power zoom not compatible)". I have looked around a lot and can't decipher which lens or lenses they might be referring to. Does this mean auto focus won't work with recent digital lenses or earlier ones? Have looked at other Pentax models (K70, K-3ii) and they don't have this limitation on their respective pages. Is this something specific to this new model?
Hope someone knows something about this/my issue, may not be a lot of info out there since it hasn't been released.
Thnx for reading

[UncleVanya]

Power Zoom appeared in some FA lenses. The lenses will work on the KP but the power zoom functions will not. Most of the Pro K-(single digit) bodies permit the basic Powerzoom to work but not the full feature set typically. The power zoom lenses all allow for manual zoom as well so no worries.

[boriscleto]

KAF2 was introduced in 1991 with the PZ1. Only certain FA lenses had power zoom (mostly FA*). All Pentax autofocus lenses will work with the KP (with the exception of the KF 35-70/4 from the ME F)

Pentax FA Zoom Lenses - Reviews and Specifications - SLR and Interchangeable Lenses - Pentax Lens Reviews & Lens Database

Pentax K-Mount Lenses Explained: The differences between various Pentax lens series

[ramseybuckeye]

Looking intently at purchase of the KP but don't know much of anything about the Pentax line. On the KP web page under compatible lens they list this, "KAF2 (power zoom not compatible)". I have looked around a lot and can't decipher which lens or lenses they might be referring to. Does this mean auto focus won't work with recent digital lenses or earlier ones? Have looked at other Pentax models (K70, K-3ii) and they don't have this limitation on their respective pages. Is this something specific to this new model?
Hope someone knows something about this/my issue, may not be a lot of info out there since it hasn't been released.
Thnx for reading

All Pentax lenses are compatible (except Q or 110), older screw mount lenses and medium format lenses would need an adapter. Years ago a few lenses were made with power zoom. The power zoom function won't work but otherwise the lens will work fully. More precise, D FA, DA, FA, F, A, M, and K series all work without adapters, and that's a lot of lenses!

[Adam]

Looking intently at purchase of the KP but don't know much of anything about the Pentax line. On the KP web page under compatible lens they list this, "KAF2 (power zoom not compatible)". I have looked around a lot and can't decipher which lens or lenses they might be referring to. Does this mean auto focus won't work with recent digital lenses or earlier ones? Have looked at other Pentax models (K70, K-3ii) and they don't have this limitation on their respective pages. Is this something specific to this new model?
Hope someone knows something about this/my issue, may not be a lot of info out there since it hasn't been released.
Thnx for reading

In short, and Pentax lens will work, and AF will be supported if the lens has it.

[Lowell Goudge]

While most people say power zoom lenses are not compatible, no one tells the OP what these lenses did.

Aside from having an electrically powered zoom, which will work, they had a bunch of of special functions that could be used. These were from memory

-image size tracking, which was used with predictive AF so that as a subject moved forward or away from the camera, as tracked by the AF, the zoom would also change to keep the framing the same in the viewfinder
-zoom through exposure, for long exposure with streaking lights, either zooming in or out.
-I believe there was a zoom clip that would automatically return to a preset focal length
- automatic zoom / focus on pier down to retract the lens to minimum total length

It is these functions which were all possible with the PZ1 and PZ1p that are not supported.

When Pentax came out with HSM motors, they used the power zoom contacts to power the motor, but never brought back support for the PZ lens functions, even though the release of the K10 promised eventual support for PZ functions

[UncleVanya]

While most people say power zoom lenses are not compatible, no one tells the OP what these lenses did.

Aside from having an electrically powered zoom, which will work, they had a bunch of of special functions that could be used. These were from memory

-image size tracking, which was used with predictive AF so that as a subject moved forward or away from the camera, as tracked by the AF, the zoom would also change to keep the framing the same in the viewfinder
-zoom through exposure, for long exposure with streaking lights, either zooming in or out.
-I believe there was a zoom clip that would automatically return to a preset focal length
- automatic zoom / focus on pier down to retract the lens to minimum total length

It is these functions which were all possible with the PZ1 and PZ1p that are not supported.

When Pentax came out with HSM motors, they used the power zoom contacts to power the motor, but never brought back support for the PZ lens functions, even though the release of the K10 promised eventual support for PZ functions

There are bodies that do not power the PZ system - I was under the impression that the KP was one of those. The K-50 I thought would not (despite what was said earlier) and the K-3 does (I can attest to this from having used an FA* 80-200 with both. But I could be misremembering the K-50 behavior but I do not think I am...

Pentax Lens Power Zoom

[E-man]

I have two power zoom lenses, a 28-105mm and a 100-300mm. Power zoom is a nifty feature but not something to go out of your way for. My K10D and Samsung GX-20 (K20D clone) support the basic power zoom function but not the advanced features. My K30 also has the KAF2 contacts but does not support the power zoom features at all. My power zoom lenses are still usable on that camera as well as my K-x, which doesn't have the KAF2 contacts. I just snap the zoom ring back toward the camera body and it zooms manually. Any K-mount lens should work just fine with your camera. The only ones I'd be slightly wary of are older third party manual focus lenses that have the dreaded Ricoh pin, which is located where it would interfere with the camera's autofocus drive shaft. I have one such lens and it works fine as long as I put the camera into manual focus mode before trying to mount the lens.

[robert52]

I once had a power zoom lens a 28/80 on my PZ1 & your not missing much. I found it a pain better just doing it manual , As far as I know no one else did it with any other camera with lens you can remove

[RobA_Oz]

I have power zoom on my FA*28-70 and my FA*80-200, both of which are heavy lenses, and that facility is certainly very nice to have for handheld work. If you've only ever had a lightweight zoom with it, I can see that you wouldn't miss it much, but my experience is different, with the FA* lenses.

The advantage is that you don't have to move the hand that cradles the lens to a great extent, in order to operate the zoom, which is obviously less of an issue with a light lens. I should have thought that having the power zoom and the zoom presets that were available with the PZ film bodies might have been a good feature with the new heavier DFA zooms, but it seems not, from the company's viewpoint.

Perhaps it's just that most people haven't owned or used one of the FA* zooms, let alone used one with a PZ body, so they don't see the advantage.

[lithedreamer]

I once had a power zoom lens a 28/80 on my PZ1 & your not missing much. I found it a pain better just doing it manual , As far as I know no one else did it with any other camera with lens you can remove

As I recall, some cinema lenses have motorised zoom, where it's much more useful than in photography.

[robert52]

As I recall, some cinema lenses have motorised zoom, where it's much more useful than in photography.

I guess I could see a usage there I guess when I think od DSLR or SLR I am only thinking of still pictures . To be honest with my K3 or K7 I have never used the video part other than when I got it to try it

[Lowell Goudge]

There are bodies that do not power the PZ system - I was under the impression that the KP was one of those. The K-50 I thought would not (despite what was said earlier) and the K-3 does (I can attest to this from having used an FA* 80-200 with both. But I could be misremembering the K-50 behavior but I do not think I am...

Pentax Lens Power Zoom

You need to check if the body is KAF2 KA2 KAF3 or KAF4.

I think support might be a function of actual lens mount definition not the presence of the two power contracts

[boriscleto]

I think support might be a function of actual lens mount definition not the presence of the two power contracts

Evert K-mount camera since the K10D, with the exception of the K100D/K110D, has had the power contacts. But only the high end cameras have limited Power Zoom functionality.

[UncleVanya]

Evert K-mount camera since the K10D, with the exception of the K100D/K110D, has had the power contacts. But only the high end cameras have limited Power Zoom functionality.

Correct. It appears to be a function of firmware as the mount does not differ between the k-3 and k-50 for example. Also on the k10d it was firmware dependent.

---------- Post added 02-21-17 at 10:58 AM ----------

It appears mosphotos.com is down at least their pages related to Pentax lenses are. Try archive.org versions:

http://web.archive.org/web/20160602132559/http://www.mosphotos.com/PentaxLensPowerZoom.html