Canon 1D MIII has a
10.0MP APS-H (28.7 x 18.7 mm ) sized CMOS sensor . On the other hand, Canon 90D has a
33.0MP APS-C (22.3 x 14.9 mm ) sized CMOS sensor and features DIGIC 8 processor.
Canon 90D's sensor provides 23MP more than Canon 1D MIII'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 1D MIII and 90D sensor size comparison.
Sensor Size and Resolution Comparison image of Canon 1D MIII and Canon 90D Cameras
As seen above, Canon 1D MIII has a 1.6x Larger sensor area than Canon 90D. 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 1D MIII
or the
Canon 90D ,
including hyperfocal distance.
One thing to watch when comparing these two: they have different sensor sizes
(APS-H versus APS-C),
so compare them at the same framing rather than the same focal length.
Put the same focal length on the smaller sensor and it will show less depth of
field, not more, because it also crops tighter. The calculator shows the
full frame equivalent focal length for each body so you can match the framing.
