Pentax Lenses
Pentax lenses were first badged as Takumar. The Takumar branded lenses were well respected for their line of Super Takumar, which designated the high performance coating applied to the lens as well as the optical formulas used to make them. The majority of the industry at the time was still satisfied with the variations of the "plumb" coating process and later some of the two and three layer processes as well. Asahi Pentax soon introduced the Takumar Super-Multi-Coated line of lenses which was a 7 layer process as the industry had just caught up with similar forms of 5 layer multi-coated optics. Eventually Asahi Optical and Pentax slowly shifted much of their lens production under the Pentax name and transitioned some of the successful designs that were first introduced under the Takumar name to use Asahi/Pentax badging as well as beginning to use the "smc" abbreviation. Eventually the Asahi partnership disappeared and the Pentax name became solely used. Pentax lenses saw many feature changes to answer the market, such as: incorporating "Auto-Aperture" with the M42, the light weight and compactness with the 'M' series, Aperture Priority overrides with the 'A' series, and Auto-Focus with the 'F' series. Modern Pentax lenses for digital SLR cameras have seen the elimination of the aperture ring completely as found on Pentax DA and D-FA series lenses. They use the Pentax KAF mount (and its variants, KAF2, KAF3 and KAF4). All of these lenses have an autofocus feature, either operated from the camera body or from an internal SDM motor. Pentax compatible lenses are also made by third-party companies.
Takumar brand lenses were supplied with Pentax cameras from the late 1950s until the mid 1970s using the M42 (Pentax) Screwmount. Asahi Optical soon began supplying lenses using the Pentax name from 1975, when they introduced the bayonet (K) mount, although Takumar-branded M42 screw lenses continued to be available new for a period. 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. Similarly, the introduction of the 7-layer coating first used with the Takumar name and later as Pentax raised controversy. It had doubters to its durability as well as its claims of flare control. Pentax's had confidence in the technology and demonstrated this by keeping a lock on the patent for quite a while. 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. Pentax's digital interchangeable-lens camera bodies maintain compatibility with any Pentax K mount and even the M42 screwmount (with a Pentax adapter) ever made. 35mm and 645 lenses optimized for digital cameras are currently in production.
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