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Abbreviations

Specification

Sources of data

• Manufacturer's technical data.
• Pentax 35mm SLR lenses (September 1989).
• Pentax 35mm interchangeable lenses operating manual (August 2003).
• Pentax lenses & accessories booklet (December 1986).
• Pentax 35mm SLR lenses.
• Pentax Z-1P booklet (PUB. 016901) (September 1995).
• Pentax A3 booklet (PUB. 08061) (January 1985).
• Pentax cameras booklet (PUB. 06091, 40 pages) (March 1987).
• Pentax SLR cameras booklet (PUB. 050101) (September 1988).
• Pentax - A complete selection of top-performance cameras booklet (PUB. 040201) (October 1997).
• Pentax ZX-M booklet.

Manufacturer description

The exaggerated perspective of this lens and its amazing depth of field make it an invaluable creative tool, covering a full 180-degree angle of view. Its fast maximum aperture allows shooting under poor lighting conditions. Compared to conventional fish-eye lenses, it has a very little spherical aberration and much improved contrast and resolving power. It has three built-in filters (skylight, Y2 and O2) and a rear mount for gelatin filters.

Pentax-A series

The third generation of lenses designed for Pentax 35mm SLR cameras with bayonet mount. Introduced with the Pentax super A in 1983.

• Robust, all-metal design with recessed focusing distance scale;
• Fully automatic diaphragm;
• Support for TTL open-aperture metering;
• Electronic contacts for transmission of aperture information;
• "A" setting on the aperture ring for automatic aperture control in the Programmed AE and Shutter-priority AE modes;
• Extremely accurate manual focusing with rubberized focusing ring;
• Multi-layer anti-reflection coating.

Typical characteristics of fisheye lenses

• Extreme angle of view (at least 180° diagonally);
• Circular types (the image circle of the lens is inscribed in the image frame) or diagonal types (cover the entire image frame);
• Usually of equidistant projection type, with the distance from the picture center to any given point always proportional to the angle from the optical axis to that point;
• Huge barrel distortion;
• Short closest focusing distance (0.20 - 0.30m with 35mm full-frame prime lenses);
• Very large depth of field, eliminating the need for autofocus or precise manual focusing;
• Due to the extreme angle of view and convex front element, front filters cannot be used;
• Often equipped with a filter turret with swivel-mounted filters;
• Often come with a small, built-in petal-shaped lens hood.

Other fisheye lenses in the Pentax K system

Lenses with similar focal length