Both Canon G15 and Olympus TG-630 iHS have 12.0 MP resolution sensors but Canon G15's sensor is 1/1.7-inch (7.44 x 5.58 mm ) and Olympus TG-630 iHS's sensor is 1/2.3-inch (6.17 x 4.55 mm ).
Since Canon G15's has a larger sensor area with the same resolution, this means that it also has a larger pixel area hence better light collecting capacity for a given aperture compared to Olympus TG-630 iHS.
Below you can see the G15 and TG-630 iHS sensor size comparison.
Sensor Size and Resolution Comparison image of Canon G15 and Olympus TG-630 iHS Cameras
As seen above, Canon G15 has a 1.5x Larger sensor area than Olympus TG-630 iHS. 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 G15
or the
Olympus TG-630 iHS ,
including hyperfocal distance.
One thing to watch when comparing these two: they have different sensor sizes
(1/1.7-inch versus 1/2.3-inch),
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.
