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Pentax K-Mount Lens Series Explained: The differences between various Pentax lens series
In a nutshell
There are several series of Pentax K-mount lenses; the ones currently being produced include
the DA (digital), DA L (cheap digital kit), D FA (full-frame, digital optimized), and FA (full-frame) series. While all Pentax K-mount lenses ever produced are compatible with all current Pentax DSLRs (in some cases with restrictions in that not all exposure modes of the camera are supported by old lenses), there are significant differences between each lens series and each has different features. Furthermore some of the newer lenses do not work with older cameras. We'll be exploring the differences between the various K-mount series lenses in this article . . .
DA lenses (with a few exceptions) feature a Quick Shift focusing system that allows the focus to be fine tuned with the focusing ring on the lens without setting the camera focus selector to "MF".
DA L lenses are a light weight edition of their DA counterparts. They have a bayonet mount made of plastic rather than stainless steel and they do not have the quick shift focusing capability.
DA* Lenses: The DA series includes a number of "star" lenses (DA*) with top notch optical and mechanical engineering. All DA* lenses have the Quick Shift focusing system and - despite not having the WR designation - are also weather sealed.
Pentax K-Mount Lenses Explained: The differences between various Pentax lens series
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