Photo Corners

A   S C R A P B O O K   O F   S O L U T I O N S   F O R   T H E   P H O T O G R A P H E R

Enhancing the enjoyment of taking pictures with news that matters, features that entertain and images that delight. Published frequently.

Ricoh Announces Pentax-D FA 21mm f2.4 Prime Share This on LinkedIn   Tweet This   Forward This

20 October 2021

Ricoh has announced the HD Pentax-D FA 21mm f2.4ED Limited DC WR with a 35mm equivalent of 35mm. It's the first D FA-series lens designed "to optimize the visual characteristics of digital images," the company said.

Ricoh noted, "It captures the prevailing ambience and true-to-life sense of depth of the scene and makes photography enjoyable for its users -- essential elements of the Pentax Limited series. The 21mm ultra-wide-angle focal length, not previously available in the FA Limited series, adds a new perspective of visual expression for the Limited series."


Highlights of the new prime include:

  • K-Mount
  • Full-frame format
  • Aperture Range: f2.4 to f22
  • Minimum Focusing Distance: 7.1 inches
  • High-grade multi-layer HD coating
  • 11 elements in 8 groups
  • 4 extra-low dispersion elements
  • Super extra-low dispersion element
  • Rounded 8-blade diaphragm
  • Weather-resistant construction
  • Front filter thread: 67mm


Specifications for the 21mm lens include:

Mount K Mount
Focal Length 21mm (35mm equivalent)
Aperture f2.4 to f22
Angle of View 92°
Minimum Focus 7.1 inches
Magnification 0.26x
Optical Design 11 elements in 8 groups
Autofocus Yes
Image Stabilization No
Filter Thread 67mm
Dimensions 2.9 x 3.5 inches
Weight 14.7 oz.


Pentax said the 21mm lens would be available in November for $1,499. Adorama and B&H are both now accepting pre-orders.

HD Pentax-D FA 21mm f2.4 ED Limited DC WR

An ultra-wide-angle single-focus lens for use with Pentax K-mount full-frame dSLR cameras:Developed as the first D FA-series model of the new-generation Pentax Limited series

TOKYO -- Ricoh Imaging has announced the launch of the HD Pentax-D FA 21mm f2.4ED Limited DC WR. Designed for use with Pentax K-mounted full-frame dSLR cameras, this ultra-wide-angle single-focus lens is the newest model of the Pentax Limited series of lenses, highly acclaimed for their distinctive image rendition and superb exterior design.

Developed as the latest model of the Pentax Limited series -- renowned for their meticulous attention to every detail, from distinctive image rendition to distinctive appearance with the machined aluminum lens barrel -- this ultra-wide-angle lens covers the image circle of 35mm full-frame dSLR cameras. In the Pentax Limited lineup, it is also the first D FA-series lens designed to optimize the visual characteristics of digital images. This is part of Pentax's attempt to reach a level of imaging performance that can't be measured simply in numerical values. It captures the prevailing ambience and true-to-life sense of depth of the scene and makes photography enjoyable for its users -- essential elements of the Pentax Limited series. The 21mm ultra-wide-angle focal length, not previously available in the FA Limited series, adds a new perspective of visual expression for the Limited series.

Main features

1. Exclusive Limited-series quality with optimized image rendition and fine texture description

True to the Limited series design concept, this lens was developed to provide a distinctive visual expression. This could be achieved only by conducting a series of image quality assessments using a vast number of captured images and by feeding the results back into the design process, along with various numerical evaluations using measuring instruments.

When used for distant subjects such as landscapes, it assures solid, uniform image rendition across the image field. By further closing the aperture down, it delivers sharp, clear, high-resolution images, even at the edges. Its optical characteristics change for close-range photography. At open aperture, it provides a mild bokeh (defocused) effect in the background while capturing the main subject in sharp, crisp focus. This lets you make the subject stand out against a defocused background, with the exaggerated perspective typical of ultra-wide-angle lenses. At a minimum focusing distance of 18 centimeters, it can create a variety of visual expressions, depending on the subject being captured.

To create a more attractive exterior design, the lens barrel, hood and cap are meticulously machined from high-grade aluminum. In every way, this lens is an exceptional image tool that brings greater joy and inspiration to your photography.

2. Exceptional optics incorporating the latest optical technologies

The lens optics incorporates four ED (Extra-low Dispersion) glass and one Super ED (Extra-low Dispersion) glass optical elements to minimize chromatic aberration and prevent color bleeding, not only in the main in-focus area, but also in the surrounding defocused areas. It also features a large-aperture negative meniscus optical element, a biconvex aspherical glass-mold optical element and a high-refraction glass optical element in the first lens group, to reduce the overall size despite the ultra-wide-angle design, while delivering outstanding imaging performance for sharp, crisp images without fuzziness, even in the peripheral areas.

The lens also features Pentax-original HD Coating. Compared with conventional multi-layer coatings, this high-grade, multi-layer coating reduces the average reflectance in the visible spectrum to less than 50 percent, effectively minimizing flare and ghost images even in demanding lighting conditions such as backlighting.

3. Electromagnetic diaphragm mechanism for high-precision exposure control

This lens incorporates an electromagnetic diaphragm mechanism to assure high-precision exposure control when used in combination with compatible dSLR cameras. It assures smooth, worry-free video shooting in locations prone to considerable brightness changes, such as a stage with rapidly changing lighting conditions or a forest with filtering sunrays.

4. Dependable weather-resistant construction

For use in demanding conditions -- such as at waterfronts or in sudden rainfall -- the lens features a dependable weather-resistant construction. By pairing it with a Pentax weather-resistant dSLR camera body, the user can create a highly dependable, airtight digital imaging system that performs superbly even in the most demanding shooting locations -- in rain or mist or at locations prone to splashing water.

5. Other features

  • SP (Super Protect) Coating to keep the lens front surface free of dust or stains
  • Serial number assigned to each lens (from 0000001 for the black model; from 1000001 for the silver model
  • Built-in motor to drive the AF mechanism for smooth, quiet autofocus operation
  • Eight-blade circular diaphragm to produce beautiful light beams with point light sources, while creating a natural, beautiful bokeh (defocus) effect at open and larger apertures
  • QFS/A (Quick-Shift Focus System) for instant shift to the manual-focus mode without requiring focus-mode switching operations, after the subject has been captured in focus by the camera's autofocus system

BackBack to Photo Corners