In digital cameras and research tools, still and dynamic images are captured using image sensors called CCDs. A CCD sensor is a planar integrated circuit that houses a collection of pixels, which are light-sensitive components that collect incoming light and convert it into electrical impulses. These impulses are used by other parts of the gadget to build a digital replica of the original picture.

The sharpness of a CCD, or the quantity of actual pixels on the camera, determines the clarity of the picture it produces. Megapixels, or the overall number of pixels in millions, are used to describe the sharpness of a camera. An picture produced by a 16 Megapixel camera, for instance, has twice as many total pixels as an 8 Megapixel image, making it more detailed. A literally bigger sensor may be able to fit more pixels than a smaller one or may have larger, more light-sensitive pixels. Infrared photos and night-vision video capture are made possible by the ability of CCD devices to sense light outside the visible range.

Unfiltered sensors only create a monochromatic picture because CCDs only record the quantity of light that strikes the sensor and not the hue of that light. Red, green, and blue (RGB) filters can be used by CCDs to sort out different colors of light before merging them to create a full-color picture. In order to record full-color picture data more quickly, some devices even have three distinct CCDs, one for each of the colors red, blue, and green.

Despite the fact that many early digital cameras used CCDs, other kinds of picture processors that were quicker and less prone to overexposure later emerged. Ultimately, CMOS image sensors replaced CCD image sensors in the majority of market and commercial digital cameras. However, when overexposure is not a problem, CCDs create higher-quality pictures, so they are still utilized in research and medical equipment. Even in the hostile atmosphere of space, they are used to capture images of distant galaxies using cameras on floating satellites.