A sensor is the digital camera's equivalent to film. It contains millions of tiny light-detecting areas called photosites, which convert light into an electric charge. After exposing the sensor to light, this charge is read from each pixel and converted into a digital image.
my first day with 6D, upgraded form 50D. Wouldn't be pixel peeping but something unusual caught my eye when I opened photos in Lightroom this morning. The color noise pattern is completely different ...