Pentax K-3 has a 24.0MP APS-C (23.5 x 15.6 mm ) sized CMOS sensor and features Prime III processor. On the other hand, Canon 5DS has a 51.0MP Full frame (36 x 24 mm ) sized CMOS sensor and features Dual DIGIC 6 processor.
Canon 5DS's sensor provides 27MP more than Pentax K-3'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 Pentax K-3'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 K-3 and 5DS sensor size comparison.
Sensor Size and Resolution Comparison image of Pentax K-3 and Canon 5DS Cameras
As seen above, Canon 5DS has a 2.4x Larger sensor area than Pentax K-3. 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
DxOMark is a benchmark that scientifically assesses image quality of camera sensors. It 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. Pentax K-3 and Canon 5DS sensors have been tested by DxO and the results show that 5DS has a better overall score of 87, 7 points higher compared to K-3's score of 80.
| Model |
Overall |
Color Depth |
Dynamic Range |
Low-light ISO |
|
Pentax K-3 |
80 |
23.7 bits |
13.4 Evs |
1216 ISO |
|
Canon 5DS |
87 |
24.7 bits |
12.4 Evs |
2381 ISO |