Some thing to think about
[ how much time to spend thinking is up to the buyer ]
but as I understand it, the " latest and greatest " [ so to speak ] changes in Pentax lenses is the
PLM - Pulse Motor (PLM) system powering the autofocus and the
KAF4 mount.
" PLM - "PLM" means this lens uses a pulse motor, which is near-silent and substantially faster than both the older screw-drive design and Pentax's other silent motors.
Read more at: https://www.pentaxforums.com/reviews/hd-pentax-da-55-300mm-f45-63-ed-plm-wr/specifications.html#ixzz56C4agseG"
" The KAF4 Mount and Compatibility
The lens mount is made of metal, and encircled by the trademark bright orange WR gasket, designed to keep water and dust away from your sensor and other delicate components. If you look closely at the back of the lens, you'll also notice that there's no aperture stop-down lever. That's due to the brand-new KAF4 mount designation, which introduces fully electronic aperture control to Pentax lenses.
The upside to the move to KAF4 is that the lens now has fewer moving parts, and that aperture control makes less noise. If you don't have a physical aperture lever, it can't get jammed. The downside is that this lens can only be used by cameras that recognize the new KAF4 mount. As of early 2017, the list includes the K-1, K-3, K-3 II, K-S2, K-S1, K-50, K-70, and KP. All future bodies should also be KAF4-compatible. All of the aforementioned cameras save the K-70 and KP first need a firmware update to support this lens. "
Read more at:
HD Pentax-DA 55-300mm F4.5-6.3 PLM WR RE Review - Construction and Handling | PentaxForums.com Reviews
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This chart shows which Pentax Camera Bodies - the K 1, K-3, K-3 II, K-50, K-70, K-S1, K-S2 - can function with such a system ( and keep in mind, currently only one Pentax lens uses it )
" KAF4: This is a KAF3 mount without an aperture stop down lever. Lenses with the KAF4 mount will only work on camera bodies that support electronic aperture control (cameras from 2013 and newer, except for the K-500). "
The Pentax Camera Lens Compatibility Chart
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how many future Pentax lenses will feature PLM and the KAF4 mount - I have no idea
but if you don't invest in one of the cameras listed above, such lenses will not work if my understanding is correct
do you need the " latest and greatest " development in a Pentax lens, not necessarily but you might want it
Last edited by aslyfox; 02-05-2018 at 04:39 AM.