Canon SD990 IS has a
15.0MP 1/1.7-inch (7.44 x 5.58 mm ) sized CCD sensor . On the other hand, Canon S120 has a
12.0MP 1/1.7-inch (7.44 x 5.58 mm ) sized BSI-CMOS sensor and features Digic 6 processor.
Below you can see the SD990 IS and S120 sensor size comparison.
Sensor Size and Resolution Comparison image of Canon SD990 IS and Canon S120 Cameras
Canon SD990 IS and Canon S120 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 S120 has 21% larger pixel area (3.46µm 2 vs 2.84µm 2 ) compared to Canon SD990 IS, 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 SD990 IS
or the
Canon S120 ,
including hyperfocal distance.
