What is a camera sensor?

A camera sensor is a piece of hardware inside the camera that captures light and converts it into signals which result in an image. Sensors consist of millions of photosites, or light-sensitive spots that record what is being seen through the lens. The size of the camera’s sensor determines how much of this light is used to create the image. 

Because a sensor stores such valuable information, if there is a large camera sensor size, more information can fit, producing better quality images than smaller sensors. The size determines what you see through your camera’s viewfinder.

Smaller sensors apply cropping to lenses while larger sensors can capture much more of the scene. This full-frame from larger sensors is your traditional 35mm film. A camera sensor and its size determines image size, depth of field, resolution, low-light performance, a camera’s physical size, and more. 

A pixel is the smallest unit of a digital image that can be represented in a display device.If you have a 24-megapixel camera, it means you have 24 million photosites on your sensor. So, where does a camera sensor size come into play? Keep in mind, a high megapixel doesn’t necessarily mean better image quality. Why?

Sensor size, not megapixels, is what matters

Compare the size of a DSLR to a pocket camera or smartphone – the difference is noticeable. From this, you can conclude that the larger DSLR will accommodate a larger sensor, and in turn, a larger sensor will produce the better picture. This is why resolution doesn’t matter solely because a more advanced camera with a large sensor will trump the low-end point-and-shoot with a small sensor, even if both sport the same number of megapixels. With a small sensor, the pixels can’t capture as much light, so a pocket camera will produce images that have less dynamic range and never as clean as a DSLR. A camera with a larger sensor will also produce images with less noise, especially at high ISO.

What sensor do you need?

For online sharing purposes, like e-mail or posting to a social networking site, small sensors in compact point-and-shoots and smartphones will do the job. But if you intend to use your photos for other purposes – whether it’s printing on paper, cropping an image, or publishing it in a magazine – know that cameras with small sensors may not deliver the image quality you’re looking for.

CAMERA SENSOR SIZE AFFECTS:

• Image quality and resolution
• Depth of field
• Angle of view
• Low-light performance
• Size of camera and lenses