Canon G15 has a 12.0MP 1/1.7-inch (7.44 x 5.58 mm ) sized CMOS sensor and features Digic 5 processor. You can shoot at maximum resolution of 4000 x 3000 pixels with aspect ratios of 1:1, 5:4, 4:3, 3:2 and 16:9. G15 has a native ISO range of 80 - 12800 and it can save files in RAW format which gives you a wider room for post processing.
Canon G15 is not the highest resolution Small Sensor camera. Canon SX740 HS with its 21.0MP sensor is leading in this class. Check the comparison of Canon G15 vs Canon SX740 HS or take a look at Highest resolution Compact cameras list.
Canon G15 DxOMark Sensor Scores
DxOMark is a benchmark that scientifically assesses image quality of camera sensors. Canon G15 sensor has been tested by DxO Mark and got an overall score of 46 for its image quality. You can find the details of their analysis of Canon G15 here.
Let's look at how the size of the Canon G15's 1/1.7-inch sensor compares with other standard sensor sizes.
Comparison image of Canon G15 Sensor Size with other standard sensors
Sensor size is what determines the circle of confusion, and therefore how much
depth of field Canon G15 gives you at any given aperture.
You can
calculate
the exact depth of field for the Canon G15
at any focal length, aperture and subject distance, including the hyperfocal distance
for landscapes and how close you can get before the focus zone becomes too thin.
