What Is a Sensor When Talking About Digital Cameras and Photography?
In digital photography a sensor is the heart of every camera system. It is a solid state device which captures the light entering the camera through the lens so that it can be processed and turned into a digital image. Image sensors come in many shapes and sizes and are often referred to by their size and resolution in megapixels. Confusingly some cameras contain more than one sensor; SLRs and DSLRs often contain a dedicated Phase Detect autofocus sensor which allows the camera to use both phase detect and contrast detect autofocus ensuring superior focusing performance.