Pentax DA 35mm F2.4 vs 40mm XS vs 40mm Limited

Conclusion: DA 40mm f/2.8 XS

The smallest and lightest APS-C lens currently being made, the DA 40mm f/2.8 XS has a certain cachet built in from the get-go. We're happy to report that it's also good at what really matters: producing excellent photos. It's really quite surprising the quality you can get out of a lens that looks and feels like a body cap. (Or, at the very least, it debunks the notion of lens size/weight and image quality having any kind of correlation.)

Our test copy of the DA 40mm XS produced excellent images in all conditions, ranging from close-ups to distant landscapes.It wasn't quite as sharp at the edges and corners as our DA 35mm, but it was more consistent across the frame, and seemed to be the best all-around performer. Chromatic aberrations were comparable to the DA 35mm, though it displayed nothing near the control of the DA 40mm Limited—differences in coating, perhaps? Distortion was a non-issue. Bokeh is marginally improved over the DA 40mm Limited thanks to the nine rounded aperture blades. Autofocus was fast and accurate. The build quality was surprisingly tight and rugged for an all-polycarbonate unit, and its tiny size definitely made the camera easier to carry on long, hot summer days. I could see this lens living on my camera for large chunks of time, and I get why it was packaged as the kit lens with the K-01: it's a very good compromise choice.

As with the DA 35mm, frills are kept to a minimum. While it retains a metal mount (somewhat surprising, since it's definitely in the budget lens camp), it doesn't include a lens hood, and its insanely compact dimensions preclude any distance scale. As noted above, the construction, while rugged, is predominately plastic. Its looks are a subject for debate; personally, we liked them, but your taste may vary. Anyway, as small as it is, the looks are easy to overlook if you disagree.

Value

As an alternative to the DA 40mm f/2.8 Limited for budget-minded buyers, the DA 40mm XS is a godsend. It offers near-identical performance at a significant discount, and while it might not be quite the mechanical jewel that its big brother is, it's a very well-built piece of kit. Its only real competition is the DA 35mm f/2.4, which is faster and wider and clocks in at nearly 30% off the DA 40mm XS's asking price. We think the DA 40 XS is the nicer lens, all around, but the DA 35mm has a lot going for it as well.

Pros

• Absolutely incredibly tiny and featherweight
• Consistently great optical performance
• Fast and reliable autofocus
• Rugged build with no squeaks or creaks
• Bokeh very slightly better than the DA 40 Limited
• Very low distortion
• Kills flare dead

Cons

• Build, while good, not as nice as the Limited
• Lacking in features (distance scale, hood, etc)
• Some annoying chromatic aberrations
• Difficult to mount and unmount due to size
• Vignetting could be better

Rating