CMOS Sensor Vs CCD Sensor

When you go shopping for a digital camera, you have to deal with lots of technical terminology and the specification about the camera. And most of the times, these terminology and specifications set the price and the quality of the camera. When you are comparing various digital cameras, even within same brand, you will notice some of the features are available in one camera model and not in another one. But before you compare different bodies based on these technical terms, I think it would be better to learn about these terminology first and I am here today to help you understand the differences between CMOS and CCD sensor type used in camera body. Whether it's a digital camera or a conventional film camera, they share same basic principle which is collecting the lights (reflecting from the subject) which travels through the lens and focus them on the digital sensor or film inside the camera body. Only the difference is that the traditional film camera uses light sensitive films to record the image whereas digital camera uses digital sensor. When you are using a film camera, you have to further process the image using chemicals to get the final image but in case of digital camera, when light hits the digital sensor, it will be converted to electrons (photons) and camera software processes them instantly inside the camera and gives the results.

The digital light sensor is divided up into many small arrays of the receptor cells. Every receptor in the array is equivalent to one pixel and it is the pixels that create an image. More pixels we have, better picture quality we get because of the wide spectrum of lights hitting on the entire sensor. One simplified way to think about the sensor used in a digital camera is to think of it as having a 2-D array of thousands or millions of tiny solar cells, each of which transforms the light from one small portion of the image into electrons. Both CMOS and CCD devices perform this task using varieties of technology.


Today, most of the digital cameras use either a CMOS image sensor or a CCD sensor. Both types of sensors accomplish the same task of capturing the light and converting it into an electrical signal.

A CMOS (Complimentary metal-oxide semiconductor) chip is a type of active pixel sensor made using the CMOS semiconductor process. Extra circuitry next to each photo sensor converts the light energy into a voltage. Additional circuitry on the chip may be included to convert the voltage into digital data.

A CCD (Charged-couple device) is an analog device. When light strikes the chip, it is held as a small electrical charge in each photo sensor. The charges are then converted into voltage one pixel at a time as they are read from the chip. Additional circuitry in the camera converts the voltage into digital information.



CMOS sensors are cheaper and easier to manufacture than the CCD chips and have a great battery life. Also, they can be fabricated on just about any standard silicon production line. This is one of the key reasons behind the falling prices of digital cameras recently. Generally speaking, digital cameras that use CMOS chips are usually lighter than their CCD counterparts. However, CMOS chips do have their drawbacks as they are less sensitive to the lights and more susceptible to the digital noise, whereas CCD sensors create high-quality and low-noise images. CMOS sensor traditionally consumes little power whereas CCD sensor uses more power to operate. It consumes as much as 100 times more power than an equivalent CMOS sensor. Once upon a time, digital cameras utilizing CMOS were regarded inferior in terms of the image quality, but today however, many popular digital cameras and video cameras are increasing in popularity as CMOS technology improves. For example, Foveon's new X3 image sensor, a CMOS sensor, which is capable of recording all three colors (red, green and blue) at every cell. CMOS technology allows other circuitry to be incorporated into the same chips, making them useful to a manufacturer for the use in other electronic applications.

Conclusion:  CCD sensors tend to be used in cameras that focus on high-quality images with lots of pixels and excellent light sensitivity. CMOS sensors traditionally have lower image quality, lower resolution and lower sensitivity to the lights but usually they are less expensive and have a great battery life. CMOS sensors are now improving to the point where they can compare with CCD devices in some applications.