Pentax 20-40mm Limited HD lens review: Limited Series first zoom is sharp, well-built but pricey


posted Thursday, May 8, 2014 at 3:47 PM EDT


Over at SLRgear, we've just published our review of Pentax's newest edition to their HD Limited series of lenses: the Pentax 20-40mm f/2.8-4 ED Limited DC WR HD DA. The first zoom lens of the Limted series get the same "HD" coating treatment as the recently reviewed Pentax 35mm f/2.8 Macro Limited HD DA and Pentax 70mm f/2.4 Limited DA HD. Pentax's new High Definition coating allows a higher light transmittance and more clarity, for improved contrast and better flare reduction. 

Despite the relatively retro-esque, all-metal exterior design, there are a few more modern touches to this lens than with the other Limited series glass. The Pentax 20-40mm is weather resistant with seals throughout the barrel (7 total) and a gasket on the mount. It also has a much quieter DC autofocusing motor, and while the aperture is variable throughout the zoom, it's fairly bright at f/2.8-4 rather than the more typical f/3.5-5.6 variety. The optical layout is comprised of 9 elements in 8 groups, including 1 Extra-low Dispersion and 1 Super Low Dispersion element, and a 9-bladed rounded aperture for nice, out-of-focus backgrounds.

In terms of test results, the new Pentax 20-40mm f/2.8-4 ED Limited DC WR HD DA lens displays excellent sharpness, especially in the center of the frame or, better yet, when you stop down a bit. Chromatic aberration, distortion and vignetting are all present to varying degrees depending on focal length and aperture, but it's all very minor and something your average photo editing software should be able to clear up.

Jump on over to SLRgear to read our full Pentax 20-40mm f/2.8-4 ED Limited DC WR HD DA lens review to see our test results and read our current verdict, which are based on RAW file output.

Like other HD Limited lenses, the Pentax 20-40mm f/2.8-4 ED Limited DC WR HD DA is available in either black or silver. The lens ships with a push-on metal lens hood and front and rear caps for around $996.95: Adorama: Black, Silver | Amazon: Black, Silver | B&H: Black, Silver. By purchasing this lens, or any other product, by clicking on one of our trusted affiliates, you help keep these reviews coming!

In the meantime, check out some sample photos shot by our senior lens technician Rob Murray. You can view more sample photos, plus download the full-resolution files, over at our Flickr page.

Pentax K-5: 20mm, f/8, 1/640s, ISO 100
Pentax K-5: 29mm, f/8, 1/250s, ISO 100
Pentax K-5: 20mm, f/5.6, 1/160s, ISO 100