Looking for CMOS vs CCD information? Read on to learn more about digital camera technology or scroll down to compare and contrast CMOS vs CCD image sensors.
Digital cameras, both still and video, are everywhere, but for such a common technology they are surprisingly intricate.
Choosing a camera can be intimidating; there is a vast range of styles and prices on the market, and many consumers feel overwhelmed and simply go for the most expensive model or whatever is on sale.
Neither of these approaches is advisable — instead, do a little research. Learn what all the technical terns mean and how they apply to the type of photography you practice.
CMOS vs CCD Image Sensors
One of the most important factors in choosing a digital camera is the image sensor. As the name implies, the image sensor is a device that converts the captured light of an optical image into an electronic signal.
Most digital cameras use one of the following types of sensor:
- A Charge-Coupled Device (CCD)
- A Complementary Metal–Oxide–Semiconductor (CMOS)
So what are the CMOS vs CCD differences? CCD is an analog technology. Light striking the chip is contained as an electrical charge in the sensor.
This charge is converted to voltage one pixel at a time, and then the voltage is stored as digital information in the camera’s memory. CMOS is an active pixel sensor, which contains both a photo-detector and an amplifier. It uses this other circuitry to convert the light to a voltage and then to stored data.
Image quality is more or less equivalent between the two. A CMOS uses less power than a CCD, which means longer battery life, and is typically less expensive to manufacture.
Another advantage of the CMOS vs CCD image sensors is that CMOS sensors eliminate the problem of light bleeding over onto other pixels when one sensor’s threshold is overloaded.
However, a CMOS sensor can cause an image to tilt. For example, when trying to capture a moving object, the CMOS records pixels one row at a time, like a TV — this is what’s known as a rolling shutter and may cause the background to skew in one direction.
It can also cause problems in situations where there are flickering lights because the light intensity will vary from the top row to the bottom. A CCD captures the entire image at once, like light through a piece of film (global shutter) so there is no skew. The global shutter results in less “noise” or a more uniform quality in photos.
Is CMOS vs CCD the Most Important Comparison?
The image sensor you choose is important, but there are other factors to consider before buying a new camera. One of these is the LCD, the screen that shows you how your photo will look.
Some LCDs perform well in outdoor conditions, while others have problems with glare. If you can, try out a camera model in bright sunlight before you buy.
Another feature to consider is the zoom, and what type of zoom you need depends on how you will use the camera. Do you need a large zoom lens, meaning more than 3x? Nature photos benefit from a larger zoom lens.
Will you be taking pictures of softball games or birds in flight? If so, you need not only a large zoom lens but also a camera with a fast response time.
Also, optical zoom is preferable to digital zoom, which only blows up the size of the pixels and results in a larger image but a rough, pixelated photo.
Finally, don’t assume that more pixels are automatically better. Unless you plan on printing your photos in a large format (think poster or handbill size), you will not need the greatest number of pixels on the market. Four to six mega-pixels is more than adequate for printing standard size photos.
Popular CMOS & CCD Cameras
A popular digital single lens reflex (DSLR) camera that uses CMOS is the Canon EOS Rebel line (T2i, T3). This is a high-end, sophisticated camera. The T2i has an 18-megapixel CMOS, while the T3 has 12 megapixels.
One popular and very reasonably priced camera with CCD technology is the Canon A3300 Powershot. It has 16 megapixels and and a 5x optical zoom.
The Olympus Evolt E420 is another well-reviewed model with a 10-megapixel CMOS sensor.
The Sony Alpha line (A230L, A330L) offers a CCD sensor, 10 megapixels, and inside image stabilization for recording motionless video.
What decision you should make in the CMOS vs CCD comparison ultimately depends on your intended use and budget. Both image sensors have advantages, and neither is a clear winner.
Technology to combine the two sensors for flawless action shots with no light bleed is in the research phase, but the cameras currently available offer so many options for every level of expertise and style of photography that whichever sensor type you choose will perform to the limits of the camera itself and the user.
For more on digital cameras check out the CMOS vs CCD blog and updates page where you’ll be able to find new information as it is added to the site.