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

Sigma’s high-grade models continue to perform well with the constant aperture ultrasonic focusing 17-50mm f2.8 EX DC HSM sitting in the top slot out of those tested, and that includes Pentax’s DA* 16-50mm f2.8 and the more modest DA 16-45mm f4, albeit those models coming in second and third place respectively. The Sigma has the highest measured peak sharpness and it’s the best corrected of the 14 models in our database tested on the K-3.

Sigma 17-50mm F2.8 EX DC HSM Pentax 669 21 13
Pentax smc PENTAX DA 16-45mm F4 ED AL 335 18 11
Pentax smc PENTAX DA Star 16-50mm F2.8 ED AL (IF) SDM 736 15 10
Pentax smc DA 12-24mm F4.0 ED AL (IF) 700 15 10
Tamron SP AF 28-75mm F/2.8 XR Di LD Aspherical [IF] Pentax 499 15 9
Pentax smc PENTAX DA 18-55mm F3.5-5.6 AL II 125 15 7
Pentax smc PENTAX DA 55-300mm F4-5.8 ED 475 14 7
Pentax smc Pentax DA 18-250mm F3.5-6.3 ED AL [IF]   499 13 8
Tamron SP 10-24MM F/3.5-4.5 Di II LD Aspherical IF Pentax 499 13 8
Sigma 8-16mm F4.5-5.6 DC HSM Pentax 699 13 8
Sigma 18-200mm F3.5-6.3 II DC OS HSM Pentax 349 13 7
Pentax smc DA 18-270mm F3.5-6.3 ED SDM 749 13 7
Pentax smc PENTAX DA 50-200mm F4-5.6 ED 261 12 6
Tamron AF18-200mm F/3.5-6.3 XR Di-II LD ASPHERICAL (IF) MACRO Pentax 645 9 5

If the 16-45mm and 16-50mm models aren’t quite wide enough, as an 18-36mm equivalent, the Pentax 12-24mm f4 ED AL (IF) is in joint third place with a DxOMark score of 15 and a respectable 10P-Mpix sharpness score. With a 13.8x zoom ratio, the $499 27-375mm equivalent 18-250mm performs well if it can still be found – it has recently been replaced by the 18-270mm f3.5-6.3, which although upgraded with an ultrasonic type AF motor also comes with a hefty 50% premium in price ($749) together with a slight hit in optical performance.

The Top three performing zooms include the DA* 16-50mm f2.8 ED AL (IF) SDM and the more humble DA 16-45mm f4 ED AL, however both are bettered slightly by the Sigma 17-50mm f2.8 EX DC HSM

When compared side-by- side with the earlier K-5 the K-3 an improvement in sharpness of the DA 16-45mm f4 ED AL can be seen at every aperture and focal length. Sharpness is measured at 4P-Mpix (around 60%) higher for the K-3 over the K-5 with this particular lens (please take into account this figure pertains to peak sharpness only).


The higher pixel density of the K-3 sensor (sans AA simulation) is capable of extracting considerably more detail over the earlier K-5. The DA 16-45mm f4 ED AL shown above reveals an all-round improvement in sharpness – particularly at the longer end of the zoom range.

We’re working hard on expanding the range of Pentax lenses in our database, but we’re interested to know if there are certain models that you would like to see reviewed first. Please leave your recommendations in the comments section below.