All digital cameras record images in an electronic form. The sensor, which is the heart of a digital camera, records an image when you take a picture. Light strikes a sensor through the lens.
In 35mm terms, the sensor is “film.”
Types of digital camera sensors
CCD (Charge-Coupled Device)
A CCD is known for its superior image performance. It is technology that has been around for more than two decades. CCD image sensors are usually found on digital cameras that produce high-quality images. They are also used in image devices in science, medicine and industry.
CMOS (Complementary Metal Oxide Semiconductor)
One of the reasons for the fall in the prices of digital cameras is because of CMOS sensors. CMOS is a newer technology and cost less to manufacture than CCDs.
CMOS sensors, initially used primarily in inexpensive digital cameras, have greatly improved in image quality and are now found in advanced and high-end cameras. These smaller sensors are easier to manufacture, faster than CCDs and don’t take as much battery power.
Back-illuminated CMOS sensors
In mid-2009, Sony introduced the development of back-illuminated CMOS sensors. These sensors offer significantly enhanced imaging characteristics including better high ISO performance, lower noise and improved dynamic range. In compact digital cameras, they also provide relatively high-speed shot-to-shot time compared to cameras with CCD sensors. These sensors are found in other digital camera brands such as the Canon SD4000. If a fast frames per second rate is a priority, and you don’t want to purchase a DSLR, a compact digital camera with this type of sensor is a good choice.
What does this mean for the consumer?
Many factors, such as the quality of a lens, ISO settings and exposure, affect the look of a photo. Buy a digital camera based on overall image quality, not only sensor type.
What can be more important than the type of sensor is the size of the sensor. A larger sensor produces photos with less noise, which is desirable when taking photos in low light at higher ISO numbers. There are compact digital cameras, such as the highly regarded Canon S95 and Panasonic LX5 that have sensors larger than found in many compacts. They do very well in low light though not as good as a digital single lens reflex camera.
The size of sensors in compact cameras with back-illuminated CMOS sensors are always not larger than those found in the majority of other compacts but they do offer advantages listed above.