Pentax HD DA 20-40mm F2.8-4 ED Limited DC WR on Pentax K-3 vs Nikon AF-S NIKKOR 18-35mm f/3.5-4.5G ED on Nikon D7100 vs Canon EF 17-40mm f/4L USM on Canon EOS 7D

COMPARISON SELECTION (3 selected items max.)
Pentax HD DA 20-40mm F2.8-4 ED Limited DC WR
Pentax HD DA 20-40mm F2.8-4 ED Limited DC WR

DXOMARK Score
Best at f=30mm & f/3.5 [?]
17

Lens Metric Scores

Sharpness [?]
9 P-Mpix
Transmission [?]
3.6 TStop
Distortion [?]
0.4 %
Vignetting [?]
-1 EV
Chr. aberration [?]
7 µm
Nikon AF-S NIKKOR 18-35mm f/3.5-4.5G ED
Nikon AF-S NIKKOR 18-35mm f/3.5-4.5G ED

DXOMARK Score
Best at f=24mm & f/4 [?]
20

Lens Metric Scores

Sharpness [?]
11 P-Mpix
Transmission [?]
4.3 TStop
Distortion [?]
0.4 %
Vignetting [?]
-0.7 EV
Chr. aberration [?]
7 µm
Canon EF 17-40mm f/4L USM
Canon EF 17-40mm f/4L USM

DXOMARK Score
Best at f=24mm & f/4 [?]
13

Lens Metric Scores

Sharpness [?]
8 P-Mpix
Transmission [?]
4.4 TStop
Distortion [?]
0.2 %
Vignetting [?]
-0.5 EV
Chr. aberration [?]
6 µm