HD Pentax-D FA 21mm F2.4 ED Limited DC WR

Conclusion

The Limited lenses have a special place in the heart (and camera bag) of Pentax users. As such, when introducing a new member of that group, Pentax needed to get things right, both in terms of specifications and performances.

D FA 21mm Limited on the Pentax K-1 (Image credit: LennyBloke)

Regarding the specifications first, the D FA 21mm F2.4 Limited fits right in. Compact, beautifully made with a metal body and elegant engraving, it looks right at home next to its siblings. Despite lacking an aperture ring, the 21mm's aesthetics belongs with the others. It even includes full weather resistance, the second Limited to do so (the first being the APS-C Limited DA 20-40mm). Available in black and silver, it is the largest of the Limited primes.

Its focal length is also well selected to fit in the lineup. Pentax offers many options at the tele end, but no modern primes at the wide end on full frame. While fleshing out the Limited group, the 21mm benefits the whole K-Mount lineup.

Contrary to the previous FA Limited, the 21mm uses the KAF4, so it won't be compatible with all Pentax cameras ever made (see our compatibility checker for details). In 2021, this is of minimal impact, and it is understandable that Pentax decided to look forward instead of ensuring backwards compatibility for a tiny subset of users.

Optically, the D FA 21mm also sits well with the Limited series. It offers, in general, excellent optical performance (albeit with a few quirks) but it is its rendering which sets it apart. Subdued and subtly balanced, its bokeh, textures, and rich colors all contribute to creating images that have a signature.

Sharpness is impressive in the center at all apertures. Edges and corners are also pretty good, but not quite as much as the center except between F5.6-F11. Wide open, the lens will particularly excel when there is a main subject in the frame. To shoot broad vistas, using F8 will be advisable. The D FA 21mm will thus act differently, and adapt to different purposes, depending on the aperture selected.

Vignetting is near perfect on APS-C, and negligible beyond F4 on full frame. Wide open, it will be noticeable in some circumstances.

As mentioned above, bokeh is breathtaking. Producing beautiful highlights at all apertures, no hint of cat's eye, wonderfully smooth transitions all contribute to these excellent results.

Chromatic aberration is well controlled, however flare and ghosting are not up to the best that Pentax can offer. In particular, ghosting manifests itself frequently, particularly when using the lens on full frame. Wide lenses are prone to this, however with Pentax lenses our expectations are higher than this. On the other hand, the APS-C crop is almost devoid of corner flare.

Distortion is near perfect. For a wide angle lens, this is above expectations. 

Focusing speed is adequate, but not the best that Pentax can offer. In low light, it takes over a second to lock focus, and speeds never really get faster than 0.6 seconds. The 21mm is not a speedy lens. It is however extremely accurate and never hunts. Given the typical use case of wide lenses, pure AF speed is not a critical requirement, but given the recent improvements shown by Pentax lenses, it would have been nice to see the 21mm benefit from this.

In summary, the D FA 21mm F2.4 is a truly welcome addition to both the K-mount lineup and the Limited family. It certainly belongs within the latter. The lens measures well in our tests, without breaking new grounds. Its qualities are beyond that, in its ability to create beautiful pictures. And that is what a Limited should be.

Pros

• Superb build quality in a small format
• Excellent center sharpness at all apertures
• Impressive, class-leading bokeh
• No distortion
• Finesse and subtlety in the rendering
• Low vignetting on APS-C
• Accurate AF
• Weather resistance
• Nearly no chromatic aberration

Cons

• Vignetting on full frame
• AF underwhelming
• Flare and ghosting below expectations for a Pentax lens

Pricing

The D FA 21mm F2.4 Limited is the most expensive of all the Pentax FA Limiteds, with a US street price of $1396.95 in December 2021.

Rating

Ratings are format-specific. Handling will be influenced by the lens dimensions and weight, in particular for smaller APS-C camera bodies.

APS-C

Full frame

Who is it For?

Anyone who likes using the Limited lenses will be well served with this new addition to the group. APS-C users might prefer to use the diminutive and less expensive DA 21mm F3.2 Limited, but the two lenses render differently and the full frame option is faster.

While the D FA 21mm can serve in a myriad of ways, it will truly show what it is capable of when composing with a subject in the foreground, taking advantage of its superb bokeh to make the subject pop.

The Bottom Line

It took two decades for Pentax to add a new member to the FA Limited family. The wait was worth it, as the D FA 21mm F2.4 Limited truly belongs with its siblings. Beyond very good optical capabilities, its rendering truly set it apart, and the lens' signature quickly becomes recognizable. In an age where many lenses are designed to "test well", it is deeply satisfying to use a lens designed primarily to make pictures.

Be sure to check the user reviews or post your own if you already own this lens.