Canon A810 has a
16.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor . On the other hand, Canon D20 has a
12.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CMOS sensor and features Digic 4 processor.
Below you can see the A810 and D20 sensor size comparison.
Sensor Size and Resolution Comparison image of Canon A810 and Canon D20 Cameras
Canon A810 and Canon D20 have the same sensor sizes so they will provide same level of control over the depth of field when used with same focal length and aperture. On the other hand, since Canon D20 has 32% larger pixel area (2.34µm 2 vs 1.76µm 2 ) compared to Canon A810, it has larger pixel area to collect light hence potential to have less noise in low light / High ISO images.
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 A810
or the
Canon D20 ,
including hyperfocal distance.
