HD Pentax-D FA 21mm F2.4 ED Limited DC WR
Specifications
The HD Pentax-D FA 21mm F2.4 ED Limited DC WR lens is certainly a mouthful. Below is an explanation of various terms pertinent to this lens:
| HD | "HD" is the name of the current most advanced coatings available for Pentax lenses. Building on the famous SMC coatings, it improves contrast and flare management. |
| FA | "FA" refers to a lens designed for full frame film cameras. The lens carries information used for specific program lines, in-camera lens corrections, and so forth. |
| F | "F" is the maximum aperture of the lens, 2.4 in this case. |
| ED | "ED" means that the lens uses extra low dispersion elements to improve optical performances. |
| Limited | "Limited" lenses are high-quality lenses, almost always primes, hand-crafted, with stellar optical performances and relatively small sizes. |
| DC | "DC" means that the lens uses a direct current, in-lens motor drive for the AF system. DC is faster and more reliable than the older SDM and is much better suited for live view operation. DC also supports continuous video autofocus on compatible bodies. |
| WR | "WR" means the lens is weather resistant. It cannot be submerged but will resist splashes, rain, snow, dust and other adverse conditions. |
Below are the lens specifications.
| Lens Name |
HD Pentax-FA 21mm F2.4 ED Limited DC WR |
| Optical Formula | 11 elements in 8 groups (4 ED elements, 1 super-ED element, one high refraction low dispersion element) |
| Image Circle | 35mm (Full frame) |
| Auto-Exposure Support | Yes |
| Construction | Metal |
| Field of View | Diagonal / Horizontal APS-C: 68 ° / 59 ° |
| Aperture Range | F2.4 - F22 |
| Aperture Blades | 8 (rounded) |
| Aperture Ring | No |
| Max. Magnification | 0.26x |
| Focus Type | AF, DC |
| Minimum Focusing Distance | 18 cm |
| Internal Focus | Yes |
| Filter Thread Diameter | 67mm |
| Cap | Dedicated metal push-on |
| Hood | Built-in |
| Case | Dedicated leather pouch |
| Diameter x Length | 74 x 89 mm (2.9 x 3.5 inches) |
| Weight | 416 g |
| Pentax Mount Designation | KAF4 |
| Weather Sealing | Yes |
| Price (US MSRP) | |
| Launch Date | November 2021 |
