Canon ELPH 520 HS has a
10.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized BSI-CMOS sensor and features DIGIC 5 processor. On the other hand, Canon SX240 HS has a
12.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized BSI-CMOS sensor and features Digic 5 processor.
Below you can see the ELPH 520 HS and SX240 HS sensor size comparison.
Sensor Size and Resolution Comparison image of Canon ELPH 520 HS and Canon SX240 HS Cameras
Canon ELPH 520 HS and Canon SX240 HS 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.
Sensor size sets the circle of confusion, so it drives how much depth of field each
of these bodies gives you at a given aperture. You can calculate it exactly for the
Canon ELPH 520 HS
or the
Canon SX240 HS ,
including hyperfocal distance.