Sony T900 has a
12.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor . On the other hand, Sony TX5 has a
10.0MP 1/2.4-inch (6.104 x 4.578 mm ) sized BSI-CMOS sensor and features Bionz processor.
Below you can see the T900 and TX5 sensor size comparison.
Sony T900 and Sony TX5 have almost the same sensor size, so neither of them has any significant advantage over the other in terms of providing control over depth of field when used with the same focal length and aperture.