Nikon D40 has a
6.0MP APS-C (23.7 x 15.5 mm ) sized CCD sensor . On the other hand, Canon SL2 has a
24.0MP APS-C (22.3 x 14.9 mm ) sized CMOS sensor and features DIGIC 7 processor.
Canon SL2's sensor provides 18MP more than Nikon D40'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 D40 and SL2 sensor size comparison.
Sensor Size and Resolution Comparison image of Nikon D40 and Canon SL2 Cameras
As seen above, Nikon D40 has a 1.1x Larger sensor area than Canon SL2. 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. Nikon D40 and Canon SL2 sensors have been tested by DxO and the results show that SL2 has a better overall score of 79, 23 points higher compared to D40's score of 56.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Nikon D40
56
21.0 bits
11.0 Evs
561 ISO
Canon SL2
79
23.6 bits
13.4 Evs
1041 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
Nikon D40
or the
Canon SL2 ,
including hyperfocal distance.
