Canon SX150 IS has a
14.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor and features Digic 4 processor. On the other hand, Nikon P310 has a
16.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized BSI-CMOS sensor .
Below you can see the SX150 IS and P310 sensor size comparison.
Canon SX150 IS and Nikon P310 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 SX150 IS has 14% larger pixel area compared to Nikon P310, it has potential to collect more light on pixel level hence have less noise in low light / High ISO images.