On Tue, Jul 13, 2010 at 5:09 PM, Eric Weir <[email protected]> wrote: > > On Jul 13, 2010, at 3:41 PM, J.C. O'Connell wrote: > >> you may want to consider the K28/3.5 version, its >> reputation is better than both m or a versions. > > It was the fact that aperture can be controlled on the camera body in the A > series that attracted me. Perhaps I should be more concerned about quality of > images produce, but at this point I only have others' experience to draw on > regarding that. > > I'm a bit unclear about K as a lens series versus K as a type of lens mount. > Until this thread I assumed all -- or almost all -- Pentax lenses were K > lenses. I gather now they are distinct classifications. However, as a > reference to a lens series, I think I have yet to encounter a K lens. > > ------------------------------------------------------------------------------------------ > Eric Weir
A brief history of Pentax K mount. K -Original version of the lens mount. Mechanical aperture coupling and full-aperture metering. Supports Aperture priority and Manual exposure modes. KA - Adds electronic communication of aperture info, A position on aperture ring, support for Multi-segment metering, body control of aperture and Program and Shutter priority exposure KAF - Adds AF and basic communication of lens data (focal length, current aperture on variable-aperture zooms) KAF2 - Adds support for powerzoom, extended lens data communication (MTF data for program lines) KA2 - KAF2 without Powerzoom or AF support, unique to MZ-M/ZX-M camera 'crippled' KAF2 - KAF2 with mechanical meter coupling removed, no Powerzoom support, limited or no function with non-A lenses. Early Pentax DSLR's are this with limited function with non-A lenses (some film bodies have no function with non-A lenses) KAF3 - crippled KAF2 with SDM focusing support and basic powerzoom support. All Pentax DSLR's from the K10D and K100D Super use this mount. Pentax lens lines: SMC Pentax - Original K mount lenses, often referred to as K lenses. Many lenses are holdover designs from the SMC Takumar screwmount lenses. SMC Pentax-M - Compact lenses introduced with the M-series SLR bodies, replaced most of the common K lenses. SMC Pentax-A - KA mount lenses, replaced the M series lenses. Generally improvements optically but build quality declined SMC Pentax-F - KAF mount lenses, original AF line. SMC Pentax-FA - KAF2 mount lenses SMC Pentax-FA L - FA lenses with no aperture ring. Only 3 made and two were crap consumer lenses. SMC Pentax-D FA - New digital-oriented lenses which are fully film compatible. May or may not have an aperture ring, have Quick-Shift focus SMC Pentax-DA Digital lenses designed for DSLR-use only, will normally vignette on film (with a couple exceptions). Have Quick-Shift Focus (except 18-250) SMC-Pentax-DA L - lighter, cheaper DA kit lenses. Plastic mounts and no Quick-Shift Focus. * - indicates pro-quality lenses. All DA* lenses are weather-sealed but FA*, A* and M* lenses aren't. Limited - compact high-performance primes with high build quality WR - Weather-sealed non-* lenses, all are DA or D-FA. -Adam -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
