Pentax K-x has a
12.0MP APS-C (23.6 x 15.8 mm ) sized CMOS sensor and features Prime processor. On the other hand, Canon 77D has a
24.0MP APS-C (22.3 x 14.9 mm ) sized CMOS sensor and features DIGIC 7 processor.
Canon 77D's sensor provides 12MP more than Pentax K-x'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.
Below you can see the K-x and 77D sensor size comparison.
Sensor Size and Resolution Comparison image of Pentax K-x and Canon 77D Cameras
As seen above, Pentax K-x has a 1.1x Larger sensor area than Canon 77D. 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-x and Canon 77D sensors have been tested by DxO and the results show that 77D has a better overall score of 78, 6 points higher compared to K-x's score of 72.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Pentax K-x
72
22.8 bits
12.5 Evs
811 ISO
Canon 77D
78
23.6 bits
13.3 Evs
971 ISO
Sensor size sets the circle of confusion, so it drives how much depth of field each
of these bodies gives you at a given aperture. You can calculate it exactly for the
Pentax K-x
or the
Canon 77D ,
including hyperfocal distance.
