Canon T8i has a
24.0MP APS-C (22.3 x 14.9 mm ) sized CMOS sensor and features DIGIC 8 processor. On the other hand, Sony A500 has a
12.0MP APS-C (23.5 x 15.6 mm ) sized CMOS sensor and features Bionz processor.
Canon T8i's sensor provides 12MP more than Sony A500'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 T8i and A500 sensor size comparison.
Sensor Size and Resolution Comparison image of Canon T8i and Sony A500 Cameras
As seen above, Sony A500 has a 1.1x Larger sensor area than Canon T8i. 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.
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
Canon T8i
or the
Sony A500 ,
including hyperfocal distance.