Pentax (lens)

The semi-official 'K' family lenses are mostly of the original Takumar Super-Multi-Coated production or in other words the 7-layer process multi-coated versions that have been adapted from the M42 mount to the K-mount.

The change to the bayonet also had an impact in the industry as many other brands utilized the M42 mount and enjoyed the compatibility.

Asahi Optical and Pentax did not keep a strictly closed door on R&D as they had active partnerships with Zeiss and Tokina as well as others.

Pentax has often been active in special run lenses such as for example the Infrared quartz element lens.

In addition to the 35mm line, Pentax added professional medium format 645 and 67 cameras lenses to its lineup.

For example SMC/smc Pentax 28mm F3.5, where SMC/smc stands for Super-Multi-Coated, the lens coating introduced in the early 1970s at the end of the M42-mount era.

The F series were the first autofocus lenses (excluding the rare smc Pentax-AF 35-70mm F2.8, made only for the ME-F camera).

As with the F series, they feature an aperture ring providing compatibility with older camera bodies.

In 2009 the 100mm was replaced by a weather resistant (WR) version without an aperture ring,[11] that was co-developed with Tokina.

As the APS-C sensor has a smaller surface area than 35mm film, these lenses are not generally considered to be compatible with older cameras.

They have a plastic (as opposed to steel) mount and lack the quick-shift focusing system of their heavier siblings.

[12] As of February 2015, the DA 20-40mm F2.8-4 Limited DC WR announced in November 2013[17] stands out for being both the only zoom as well as the only weather resistant lens of the series.

[10][18] Unlike Canon and Nikon, Pentax, as well as Sony, provides "shake reduction" (SR) functionality within the camera, instead of inside each lens to be purchased.

This is advantageous as any lens can be used with full SR functionality, and the lenses are more economical to manufacture as they do not require any shake reduction equipment inside.

Many Pentax lenses, like their medium- to high-end camera bodies, are weather-sealed, allowing for their continued use in poor weather and wet locations.

This allows to change the focal length with a small twist of the zoom ring at three different speeds.

[21] Most Pentax digital SLRs today do support the first two basic functions of Power Zoom lenses.

Cameras with a "crippled K-Mount" cannot read the set f-stop of K and M series lenses and must stop-down momentarily to meter in case the adjusted aperture is a stopped down one.

Pentax KAF3 lenses do only have an own internal autofocus motor and are not fully compatible with some early DSLR models like the *istD.

- PLM (Pulse) Glass: AL (aspheric lens) - ED (extra low dispersion lens) Coating: smc (super multi coating) - HD (high definition coating) Sealing: WR (weather resistant) - DA* (lens is sealed) - AW (All Weather) Features: PZ (Power Zoom) - QS (Quick Shift, most DA & all D FA lenses) - RE (retractable lens barrel) - digital aperture control (with PLM lenses on KAF4)) - IF (Internal focusing) See also: Pentax K-mount lenses