Canon SD3500 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 S5300 has a
16.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CMOS sensor .
Below you can see the SD3500 IS and S5300 sensor size comparison.
Canon SD3500 IS and Nikon S5300 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 SD3500 IS has 14% larger pixel area compared to Nikon S5300, it has potential to collect more light on pixel level hence have less noise in low light / High ISO images.