Canon SD1300 IS has a
12.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor and features Digic 4 processor. On the other hand, Canon SD1200 IS has a
10.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor .
Below you can see the SD1300 IS and SD1200 IS sensor size comparison.
Canon SD1300 IS and Canon SD1200 IS 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.