Are there any advantages to a black and white (B&W) security camera?
Color surveillance cameras have come to dominate the security camera market place and in situations involving good lighting (such as daytime viewing or a well-lit department store) color cameras provide excellent images. After all, color security cameras can provide useful information such as color of clothing that a suspect was wearing, color of a get-away car etc. However, the color information is dependent upon sufficient illumination in the visible light portion of the electromagnetic spectrum. In other words, you need good lighting with visible white light to get color video.
Night time viewing situations are a different story. Practically all color security cameras switch over to black & white viewing when the ambient light levels diminish below a certain point. Most modern high-quality color security cameras have built-in circuitry that senses the ambient light levels, and adjusts the camera settings for night time viewing. So even the best color security cameras see only in black & white when it comes to night time viewing.
So what are the advantages to black & white security cameras?
1) Lower cost - Generally, B&W security cameras cost less due to the fact that they are easier/cheaper to manufacture than color cameras. There are exceptions since there are some very high quality B&W security cameras that cost more due to their exceptionally good light gathering ability in low-light conditions. However, as a general observation, most consumer oriented B&W surveillance cameras are lower priced than comparable color surveillance cameras.
2) Brighter images in low-light conditions - On average B&W security cameras produce brighter images in low-light situations. This is not to say that some high quality color cameras won't be brighter than a cheaper B&W camera. You can get a color camera that is brighter than the B&W camera but you will pay more. The image sensor chips (such as the Sony Ex-View CCD) in those high-end color cameras that give a brighter night-vision image are more expensive to manufacture. However, if you compare a color and B&W camera of equal quality, the B&W will be brighter at night, because the color camera requires a special filter (which is imprinted over the sensor) that reduces the amount light reaching the CCD imaging sensor.
3) Higher resolution - A B&W camera will generally have a higher resolution and therefore sharper image compared to a color camera in the same quality/price range. The reasons for this are technical in nature, but in a nutshell the color security camera needs to utilize more of the CCD sensor resources to pick up the three primary colors red/green/blue (RGB) as well as the intensity of light striking it at each pixel sensor, whereas the B&W security camera only sees varying degrees of light intensity (grey scale). Therefore, the CCD sensor in the B&W security camera is fully utilized to making an image and does not have to divert some of it's resources (pixel sensors) towards picking up color information.
So while color security cameras are a great component of a surveillance system for day time situations, there are some advantages to B&W security cameras that should not be overlooked, particularly those involving low-light situations.