Sony TX66 has a
18.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized BSI-CMOS sensor and features BIONZ processor. On the other hand, 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.
Below you can see the TX66 and SX150 IS sensor size comparison.
Sony TX66 and Canon SX150 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. On the other hand, since Canon SX150 IS has 28% larger pixel area (2.01µm2 vs 1.56µm2) compared to Sony TX66, it has larger pixel area to collect light hence potential to have less noise in low light / High ISO images.