Canon SX60 HS has a 16.0MP 1/2.3 (6.17 x 4.55 mm ) sized BSI-CMOS sensor and features DIGIC 6 processor. On the other hand, Canon SX50 HS has a 12.0MP 1/2.3" (6.17 x 4.55 mm ) sized BSI-CMOS sensor and features Digic 5 processor.
Below you can see the SX60 HS and SX50 HS sensor size comparison.
Canon SX60 HS and Canon SX50 HS have 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 SX50 HS has 18% larger pixel area (2.34µm2 vs 1.98µm2) compared to Canon SX60 HS, it has larger pixel area to collect light hence potential to have less noise in low light / High ISO images.
DxOMark Sensor Scores
DxOMark is a benchmark that scientifically assesses image quality of camera sensors. It scores camera sensors for color depth (DXO Portrait), dynamic range (DXO Landscape) and low-light sensitivity (DXO Sports), and also gives them an overall score. Canon SX60 HS and Canon SX50 HS sensors have been tested by DxO and the results show that SX50 HS has a better overall score of 47, 8 points higher compared to SX60 HS's score of 39.