Canon's large-area CMOS (complementary metal oxide semiconductor) sensor captures images with exceptional clarity and tonal range, and offers the most pixels in its class. This APS-C size sensor (22.5 x 15.0mm) has the same 3:2 ratio as film cameras, enabling an effective angle of view that is 1.6x the normal EF Lens focal length. 14-bit A/D conversion means fine transitions from light to dark tones, and a significant drop in digital and shadow noise. The EOS 40D has an extensive ISO range (from 100 to 1600, plus ISO 3200* in extended mode) which is selectable in 1/3 stop increments. The EOS 40D's CMOS sensor uses much of the new technology first seen in the EOS-1D Mark III camera. New manufacturing techniques mean each pixel is more sensitive to light, and less area between pixels is wasted on the sensor. The on-chip noise reduction electronics are also entirely new, and combine with the sensor's general design for less digital noise and better high-ISO performance than ever before. This results in larger, clearer, sharper and more detailed photographs right from the start.
* Standard output sensitivity. Recommended exposure index.
10.1 Megapixel APS-C Size CMOS Sensor
With some lenses, the peripheral AF points may become sensitive to either vertical or horizontal lines (they will not function as cross-type AF points). These lenses are: EF 35-80mm f/4-5.6, EF 35-80mm f/4-5.6 II, EF 35-80mm f/4-5.6 III, EF 35-80mm f/4-5.6 USM, EF 35-105mm f/4.5-5.6, EF 35-105mm f/4.5-5.6 USM, EF 80-200mm f/4.5-5.6 II, EF80-200 f/4.5-5.6 USM.