Photographer Know-how: Image Sensors


Part 3 of our Photographer Know-how guide examines the importance of camera image sensors and what effect sensor size will have on your pictures. Click here for part 2 of our guide, which took a look at pixels, and here for part 1’s roundup of the different types of cameras you can buy.

What is an Image Sensor?

A camera’s image sensor is the sensor used to detect, capture and convey the information used to create a picture. Image sensors do this by converting light waves as they reflect off and pass through objects into signals, the electric currents used in cameras to communicate image information.

Image Sensor Size Matters

The size of a camera’s image sensor is very important, as this determines how much light can be detected and captured in an image. Image sensors consist of millions of light-sensitive photosites; it is these photosites that capture the information displayed in an image.

The bigger the image sensor the more photosites it possesses, which allows the sensor to capture a higher level of information resulting in more detailed images. Larger image sensors provide pictures with a greater dynamic range, reduced noise and an improved low lighting performance. Similarly, large image sensors enable camera manufacturers to increase a camera’s image resolution without sacrificing the other attributes that contribute to the overall quality of an image.

Types of Digital Camera Image Sensors

There’s a couple of different image sensors used in digital cameras today:

  • Charged-Coupled Device (CCD) sensors are often found in lower priced cameras with slower continuous shooting functions.
  • Complementary Metal-Oxide-Semiconductor (CMOS) sensors often feature quicker read speeds than CCD sensors, allowing for high speed continuous shooting.
  • Black and White sensors are typically used in specialist digital cameras and as the name implies, capture image information in black and white colour.

Different brands of camera tend to use different image sensors. For example, the Sony Alpha a7 & 28-70mm Camera features Sony’s patented Exmor sensor, so remember to enquire about what sensor is included in a camera before making your purchase.

For the very best in cameras, shop in-store or online.

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Posts from the Harvey Norman blog team.

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