Best lenses for the 24-MPix Pentax K-3: Recommended primes and zooms

By Kevin Carter - Monday January 06 2014

Lens Recommendations
Introduction | Lenses measured on Pentax K3: Database Overview | Best prime lenses for the Pentax K-3 | Best zoom lenses for the Pentax K-3

Although a full-frame lens and the equivalent to a 50mm on the Pentax-K-3, the Sigma 35mm f/1.4 DG HSM A is the best performing prime overall in our database (on the K-3). It’s a big heavy lens on the Pentax-K-3 but the build and image quality is very high. Peak sharpness is measured at 16P-Mpix, 3P-Mpix higher than the next measured model (the DA Limited 35mm f2.8 Macro –either the new HD model or earlier smc version).

Sigma 35mm F1.4 DG HSM A Pentax 899 27 16
Pentax smc DA Star 55mm F1.4 SDM 640 27 11
Pentax smc DA 50mm f1.8 249 25 12
Pentax smc DA 35mm F2.8 Macro Limited 700 22 13
Pentax HD DA 35mm F2.8 Macro Limited 750 22 13
Pentax smc DA 35mm F2.4 AL 220 22 11
Pentax smc DA 70mm F2.4 Limited 545 22 11
Pentax smc D FA MACRO 100mm F2.8 WR 589 22 10
Pentax smc PENTAX D FA 50mm F2.8 Macro 444 21 12
Pentax smc FA 50mm F1.4 450 21 11
Pentax smc DA 40mm f2.8 XS 250 20 10
Pentax HD DA 40mm F2.8 Limited 550 19 9
Pentax HD DA 21mm F3.2 AL Limited 700 18 11
Pentax smc DA 40mm F2.8 Limited 360 18 9
Pentax smc DA Star 300mm F4 ED (IF) SDM 1400 17 9
Pentax smc DA Star 200mm F2.8 ED (IF) SDM 1200 17 8
Pentax smc DA 21mm F3.2 AL Limited 650 16 11
Pentax smc PENTAX DA 14mm F2.8 575 15 8
Pentax smc DA 15mm F4 ED AL Limited 510 14 9
Pentax HD DA 15mm F4 ED AL Limited 700 14 8

With the same DxOMark score of 27 points and technically occupying joint first place, albeit with a lower peak sharpness score is the Pentax smc DA* 55mm f1.4 SDM. As the equivalent to a 85mm on the K-3 it’s well corrected optically, and an excellent performer, though at $249 the more modestly priced APS-C only DA 50mm f1.8 isn’t quite as good a performer though with marginally higher peak sharpness it may appear to skew the ranking slightly when measured on the Pentax K-3.

The top three performing primes in our database on the Pentax K-3

Although we’ve not had the opportunity to analyze either the 16-Mpix K-5 II or the K-5 IIs (sans OLPF), we can compare the K-3 with the earlier K-5 (from 2010), which had related sensor. Although the overall pixel count increased 50% from 16.3-Mpix to 24.3-Mpix, the linear increase is much lower at around 22% - however, bearing in mind the Pentax K-3 has no OLPF increases in sharpness should be significant, especially with the right lenses.

Comparing the K-3 with the earlier K-5, the increase in pixel count, unsurprisingly perhaps, brings with it a tangible improvement in sharpness.


Comparing the peak sharpness measurements of the DA * 55mm f1.4 on the K-3 and K-5 side-by-side shows an improvement at every aperture setting, including smaller apertures where diffraction plays a part.