Canon 1Ds has a 11.0MP Full frame (35.8 x 23.8 mm ) sized CMOS sensor . You can shoot at maximum resolution of 4064 x 2704 pixels with aspect ratios of and 3:2. 1Ds has a native ISO range of 100 - 1250 and it can save files in RAW format which gives you a wider room for post processing.
Canon 1Ds is not the highest resolution Full frame camera. Blackmagic PYXIS 12K with its 98.8MP sensor is leading in this class. Check the comparison of Canon 1Ds vs Blackmagic PYXIS 12K or take a look at Highest resolution DSLR cameras list.
Canon 1Ds DxOMark Sensor Scores
DxOMark is a benchmark that scientifically assesses image quality of camera sensors. Canon 1Ds sensor has been tested by DxO Mark and got an overall score of 63 for its image quality. You can find the details of their analysis of Canon 1Ds here.
Let's look at how the size of the Canon 1Ds's Full frame sensor compares with other standard sensor sizes.
Comparison image of Canon 1Ds Sensor Size with other standard sensors
Sensor size is what determines the circle of confusion, and therefore how much
depth of field Canon 1Ds gives you at any given aperture.
You can
calculate
the exact depth of field for the Canon 1Ds
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.
