Canon T6i has a 24.0MP APS-C (22.3 x 14.9 mm ) sized CMOS sensor and features DIGIC 6 processor. You can shoot at maximum resolution of 6000 x 4000 pixels with aspect ratios of 1:1, 4:3, 3:2 and 16:9. T6i has a native ISO range of 100 - 12800 which can be boosted to 25600 and it can save files in RAW format which gives you a wider room for post processing.
Canon T6i is not the highest resolution APS-C camera. Fujifilm X-E5 with its 40.0MP sensor is leading in this class. Check the comparison of Canon T6i vs Fujifilm X-E5 or take a look at Highest resolution DSLR cameras list.
Canon T6i DxOMark Sensor Scores
DxOMark is a benchmark that scientifically assesses image quality of camera sensors. Canon T6i sensor has been tested by DxO Mark and got an overall score of 71 for its image quality. You can find the details of their analysis of Canon T6i here.
Let's look at how the size of the Canon T6i's APS-C sensor compares with other standard sensor sizes.
Comparison image of Canon T6i Sensor Size with other standard sensors
Sensor size is what determines the circle of confusion, and therefore how much
depth of field Canon T6i gives you at any given aperture.
You can
calculate
the exact depth of field for the Canon T6i
at any focal length, aperture and subject distance, including the hyperfocal distance
for landscapes and the very shallow focus zone you get with long telephoto lenses.
