Sony A7 IV has a
33.0MP Full frame (35.8 x 23.8 mm ) sized BSI-CMOS sensor and features Bionz XR processor. On the other hand, Pentax K-5 II has a
16.0MP APS-C (23.7 x 15.7 mm ) sized CMOS sensor and features Prime II processor.
Sony A7 IV's sensor provides 17MP more than Pentax K-5 II's sensor, which gives a significant advantage in real life. You can print your images larger or crop more freely.
On the other hand, please keep in mind that Max sensor resolution is not the only determinant of resolving power. Factors such as the optical elements, low pass filter, pixel size and sensor technology also affects the final resolution of the captured image.
Another difference between these two cameras is that Sony A7 IV's sensor lacks anti-alias (Low-Pass) filter. Removing anti-alias filter increases the sharpness and level of detail but at the same time, it increases the chance of moiré occurring in certain scenes.
Below you can see the A7 IV and K-5 II sensor size comparison.
As seen above, Sony A7 IV has a 2.3x Larger sensor area than Pentax K-5 II. Larger sensors give photographer more control on the depth of field and blurry background compared to smaller sensor when shot in same focal length and aperture.
DxOMark Sensor Scores
Both Sony A7 IV and Pentax K-5 II sensors have been tested by DxoMark. DxoMark scores camera sensors for color depth (DXO Portrait), dynamic range (DXO Landscape) and low-light sensitivity (DXO Sports), and also gives them an overall score. Of the two cameras that we are comparing, A7 IV has scored 97, 15 points higher than K-5 II.
Model |
Overall |
Color Depth |
Dynamic Range |
Low-light ISO |
Sony A7 IV |
97 |
25.4 bits |
14.7 Evs |
3379 ISO |
Pentax K-5 II |
82 |
23.8 bits |
14.1 Evs |
1235 ISO |