Pentax SMC DFA 50mm f2.8 Macro Review

There’s no such problem with this lens, though. It delivers very high resolution even at maximum aperture, and easily does justice to the 14-megapixel sensor in Pentax’s top-of-the-range K20D, for example. This level of sharpness is delivered with amazing consistency. It’s sharp at the edges as well as the centre, even wide open, and holds this sharpness as the lens is stopped down. Even at f16, where most lenses are showing marked softening due to diffraction effects, the Pentax 50mm is resolving high levels of detail. This is especially important in a macro lens, where you’re often going to be shooting at very small lens apertures to get as much depth of field as possible.

This is very much an ‘old school’ lens, complete with its own aperture ring – which makes a refreshing change when almost all makers have gone over to more cumbersome body-based aperture control.

The autofocus can be a bit slow and hesitant, especially at very close focussing distances, but this is common in macro lenses because they are having to make very large focus shifts even for small changes in the subject distance.

In fact with this and other macro lenses it’s generally easier to swap to manual focus, not least because the depth of field control needed for close-ups means you need to use a small lens aperture and focus between key parts of the subject rather than on one single plane. The Pentax has a quick-shift AF/MF mechanism on the barrel, so swapping focus modes is easy. And the manual focus control is excellent, with a really long travel and a smooth movement which makes precise focus adjustments very easy.
   

The extremely good optical performance and the high-quality build and handling make this lens look very good value indeed. In fact it costs barely more than the third-party Sigma 50mm macro, which is quite something for an own-brand lens. It equals or perhaps even marginally improves on the Sigma’s excellent optical performance too.

Finally, don’t forget that on APS-C cameras like all of Pentax’s current D-SLR range, this lens equates to an 80mm, so it would also make a pretty good portrait lens. The focal length is perfect for flattering facial proportions, and the excellent peformance wide open means you could combine shallow depth of field with biting definition.