PENTAX lens Glossary
The PENTAX Quick Shift focus system
It allows instant switching between Auto Focus and Manual Focus simply by turning the focussing ring on the lens. A clever clutch mechanism takes care of the rest.
(Aspherical Lenses) contrary to spherical, aspherical lenses do not have a uniformly curved spherical shape. The form of an aspherical lens is adapted to a specific task and the curvature of each is individually computed. The production of these lenses is accordingly complex. The greatest advantage of aspherical lenses: several types of optical aberrations can be corrected at one time. They are used particularly in highquality lenses allowing for the use of fewer lens elements so that a high luminous intensity is attained.
(Extra-low dispersion ED lens elements) Normal glass lenses tend to divide the incident light into its various colour components, as a prism would do. This happens particularly at the edges, adding unwanted colour fringing to the photo. The longer the focal length of the lens the more apparent is the fringing effect. ED glass is an exceptionally highquality special glass that prevents this socalled chromatic aberration to a very great extent.
(Inner Focusing) Each lens is composed of several groups of lens elements. With an Inner Focusing design only one of these groups is moved. Inner Focusing brings a number of advantages compared to a conventional focusing design where all the lens groups are moved: it works faster and the overall length of the lens remains unchanged so the centre of balance remains constant. additionally, since the front lens element doesn’t rotate, filters do not have to be readjusted every time the focus point changes.
“Limited Edition” is the PENTAX lens series that is characterised by extremely high quality standards. Since more expensive materials are used and a complex production process employed, PENTAX manufactures a restricted number of the “Limited Edition” lenses on a daily basis.
(super multi coating) super multi coating is the benchmark of all PENTaX lenses. smc describes a high quality coating of the lens elements that consists of seven microscopically thin layers. The normal light loss at the lens surface between air and glass is reduced from 4 % to 0. %.
The designation is for lenses designed specifically for PENTAX digital SLR cameras. They are not compatible with 35mm film SLRs.
This designation is used for lenses that are optimized for digital photography but can also be used with 35mm SLR cameras.
New High Defi nition multi-layer lens coating. Thanks to its higher light transmittance with reduced reflection, to deliver sharp, clear images free of flare and ghost images, even under demanding lighting conditions such as backlight.
SP (Super Protection) coating is a special coating of the front lens element of particular PENTAX lenses. It is based on a fluoride bonding and prevents the contamination of the lens by waterbased or oily substances. SP coated lenses are much more easily cleaned of finger marks, smears or other matter than may come in contact with the lens.
WR / AW
Water and Dust Protection Humidity and dirt are the natural enemies of high performance electronics and precision optics. AW lenses provide maximum weather-resistant and dustproof performance preventing the intru sion of drizzle and dust into the lens barrel. WR lenses come with a simpli fi ed weather-resistant construction designed to repel a light splash of water.
This diaphragm produces a natural, beautiful bokeh (out-of-focus) effect, while minimizing the streaking effect of point light sources.