Canon SD780 IS has a
12.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor . On the other hand, Samsung DV300F has a
16.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor .
Below you can see the SD780 IS and DV300F sensor size comparison.
Sensor Size and Resolution Comparison image of Canon SD780 IS and Samsung DV300F Cameras
Canon SD780 IS and Samsung DV300F 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 SD780 IS has 32% larger pixel area compared to Samsung DV300F, 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
Canon SD780 IS
or the
Samsung DV300F ,
including hyperfocal distance.