The smc PENTAX-FA 77mm f/1.8 Limited from Pentax is a short-telephoto prime well-suited for portraiture. The optical design pairs with a bright f/1.8 maximum aperture to promote greater control over depth of field for using selective focus and the seven elements in six groups design helps to realize accurate tone and color rendering. This lens also uses the Fixed Rear Element Extension (FREE) focusing system to maintain image quality, sharpness, and clarity throughout the focusing range, from 2.3' to infinity
Short-telephoto prime is designed for full-frame Pentax K-mount cameras, however can also be used with APS-C models where it will provide a 115.5mm equivalent focal length.
Bright f/1.8 maximum aperture benefits working in low-light conditions and also affords greater control over depth of field for working with selective focus techniques.
Nine-blade diaphragm contributes to a smooth bokeh quality.
Fixed Rear Element Extension focusing system helps to maintain high sharpness, clarity, and color accuracy throughout the focusing range, from 2.3' to infinity.
Built-in lens hood protects against stray light from causing lens flare or ghosting and also guards the front element from accidental scratching or impacts.
Aluminum-alloy lens housing is both durable and lightweight.
Impressive delineation performance
The design was based on the numerical evaluation by various testing instruments and also incorporates advanced evaluation using actual images. The result is an appropriate softness at aperture opening, and as the aperture closes, enables sharp imaging performance and rendering that provides a sense of space, gradations, and three-dimensional feel.
FREE system for focusing
This lens uses the FREE system that moves only the front group while keeping the rear group stationary in the lens system when focusing. This enables stable imaging performance from near to far distances.
Design with a sense of elegance and precision
The lens body uses an aluminum material for providing a design with a sense of elegance and precision. The camera body uses "finger points" made of a deep purple Shippo-yaki material for providing a firmer gripping sensation.