Canon S90 has a 10.0MP 1/1.7-inch (7.44 x 5.58 mm ) sized CCD sensor and features Digic 4 processor. You can shoot at maximum resolution of 3648 x 2736 pixels with aspect ratios of 4:3 and 16:9. S90 has a native ISO range of 80 - 3200 and it can save files in RAW format which gives you a wider room for post processing.
Canon S90 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 S90 vs Canon SX740 HS or take a look at Highest resolution Compact cameras list.
Canon S90 DxOMark Sensor Scores
DxOMark is a benchmark that scientifically assesses image quality of camera sensors. Canon S90 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 S90 here.
Let's look at how the size of the Canon S90's 1/1.7-inch sensor compares with other standard sensor sizes.
Comparison image of Canon S90 Sensor Size with other standard sensors
Sensor size is what determines the circle of confusion, and therefore how much
depth of field Canon S90 gives you at any given aperture.
You can
calculate
the exact depth of field for the Canon S90
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.
