The Pentax DA 21mm f/3.2 Limited Lens is an extremely thin, compact and light-weight wide angle lens, designed exclusively for Pentax digital SLR cameras. This lens measures only 1" (25mm) long, and weighs a mere 4.9 ounces (140 grams).
This versatile angle of view produces natural images with a moderate perspective and an expanded depth of field (or a wide in-focus area), making it ideal for many different types of subjects and occasions, including snapshots, landscape, travel photos, and architecture.
The image circle in DA-series lenses is designed to perfectly match the 23.5mm x 15.7mm size of the CCD used in Pentax digital SLR cameras to optimize camera performance. This design also contributes to a drastic reduction in size, weight and production cost, compared to 35mm-format counterparts with similar specifications.
Note: Not suitable for 35mm film SLR cameras