Understanding – Camera Sensor


What the heck is a camera sensor anyways? If you’re reading this article, you probably already understand how camera resolution affects the image quality. What is less commonly understood however, is how camera image sensor size affects the final image quality. Today we’re going to explain exactly how image sensors work, and how that translates to what you see on the camera.

Camera Image Sensors

Cameras work by focusing light through a lens onto an image sensor. An image sensor contains millions of light-sensitive spots which are used record the image seen through the lens. Therefore, a larger image sensor is able capture more information than a smaller one, resulting in a better image.

Typically, most security cameras use a sensor size of between 1/1.7” and 1/3”. The larger the sensor, the better the camera will perform in low-light scenarios. A larger sensor also results in a wider field of view (FOV), allowing the camera to see further in each direction. The trade-off is that larger sensors are more expensive to manufacture, increasing the final price of the camera.

A comparison between Sony's IMX415 and IMX274 image sensors
Sony’s Next Gen Starvis Sensor vs. Last Gen Starvis Sensor

CMOS vs. CCD Camera Sensor

CMOS stands for complementary metal-oxide-semiconductor. They utilize progressive image scanning to obtain values for each pixel and display an image. This technology has the advantage with high resolution, fast frame rate, and low power consumption. The tradeoff is more noise, and less dynamic range.

CCD stands for charged-coupled device. CCD security cameras have great dynamic range (WDR), making them an excellent choice for low-light conditions. These cameras excel when it comes to producing the sharpest image in challenging lighting environments. Their disadvantage is higher price, high power consumption and heat output, and generally slower framerate (not as important for CCTV applications).


Just as you would choose a camera based on the number of megapixels, it is important to also consider the type of sensor used in the camera. A security camera with a larger sensor will be more expensive, but can produce sharper images in lower-lighting conditions. Always ensure you pick the best camera for location where it’s going to be installed.

You can view our lineup of Starlight security cameras by clicking here.