Casio EX-S12 has a
12.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor . On the other hand, Canon A1400 has a
16.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor .
Below you can see the EX-S12 and A1400 sensor size comparison.
Sensor Size and Resolution Comparison image of Casio EX-S12 and Canon A1400 Cameras
Casio EX-S12 and Canon A1400 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 Casio EX-S12 has 32% larger pixel area compared to Canon A1400, it has potential to collect more light on pixel level hence 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
Casio EX-S12
or the
Canon A1400 ,
including hyperfocal distance.