Canon SX30 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 P610 has a 16.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized BSI-CMOS sensor .
Below you can see the SX30 IS and P610 sensor size comparison.
Canon SX30 IS and Nikon P610 have 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 SX30 IS has 14% larger pixel area compared to Nikon P610, it has potential to collect more light on pixel level hence have less noise in low light / High ISO images.