PENTAX Introduces smc DA 17-70mm f/4 AL [IF] SDM Lens

[gubak]

PENTAX DA 17-70mm f/4 AL [IF] SDM Lens Announced

One noteworthy change compared to Pentax's pro-grade DA* lenses with SDM is the use of the KAF3 (rather than previous SDM lenses' KAF2) lens mount on the 17-70mm. The KAF3 mount is almost functionally identical to the KAF2, with two contacts driving the internal focusing motor, but the new mount eliminates the secondary focus drive option via the body's focusing motor found on KAF2 lenses. Hence, rather than reverting to body-driven auto focus on older Pentax bodies (anything further back than the K10D or K100D Super), the new DA 17-70mm is manual focus only in these applications.

While users with older Pentax digital bodies may be disappointed at the loss of AF compatibility with the latest lens, the move to KAF3 spells good news for current Pentax shooters: outside of its dimunitive DA Limited glass (which will retain body-driven AF), look for new lenses from the manufacturer to feature SDM focus drive exclusively going forward.