Sony A850 has a 25.0MP Full frame (35.9 x 24 mm ) sized CMOS sensor and features Bionz processor. You can shoot at maximum resolution of 6048 x 4032 pixels with aspect ratios of 3:2 and 16:9. A850 has a native ISO range of 200 - 3200 which can be boosted to 6400 and it can save files in RAW format which gives you a wider room for post processing.
Sony A850 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 Sony A850 vs Blackmagic PYXIS 12K or take a look at Highest resolution DSLR cameras list.
Sony A850 DxOMark Sensor Scores
DxOMark is a benchmark that scientifically assesses image quality of camera sensors. Sony A850 sensor has been tested by DxO Mark and got an overall score of 79 for its image quality. You can find the details of their analysis of Sony A850 here.
Let's look at how the size of the Sony A850's Full frame sensor compares with other standard sensor sizes.
Comparison image of Sony A850 Sensor Size with other standard sensors
Sensor size is what determines the circle of confusion, and therefore how much
depth of field Sony A850 gives you at any given aperture.
You can
calculate
the exact depth of field for the Sony A850
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.
