Understanding Different Types of CCTV Cameras

Prologue: I find this as the most End-user-friendly Guide to Understanding the Different Types of CCTV Cameras available in the market. I don't own any of the below info. All credits to Aventura.


CCTV Camera Styles:

DOM Camera
Dome cameras typically are the best choice whenever possible

• When the camera is within someone’s reach domes cannot be easily manipulated or vandalized
• Domes Installs easy in drop ceilings – usually 2 screws
• Since a dome has a covered lens the direction the camera is pointing is hidden
• Domes can accommodate infra-red for Night Vision

NOTE: While dome cameras are the installation choice there are limitations. As the domes themselves are typically small you are limited in the size lens available. If you need to focus on long distances which requires a lens of 50mm focal length or greater it will not fit inside a standard dome camera. Dome cameras can be simple plastic ones or metal vandal-proof for public places.

Box Camera

• When mounting to a wall or any vertical area
• When viewing long distances where a long lens is required, which would not fit inside a dome or bullet camera
• When extreme low light conditions are not a consideration

NOTE: If the box camera is within someone’s reach the camera is usually inserted in a protective enclosure. If the lighting is extremely low box cameras can be inserted inside enclosures that have built-in infra-red illuminators but the camera must be infra-red sensitive. Meaning it is able to utilize the infra-red illuminators from an external source.

Infra-red Camera

• When there are extreme low light conditions
• When the camera is not within someone’s reach
  

NOTE: The distances infra-red cameras can see are based upon its illumination capacity. Infra-red cameras have LED’s, which cast out into the darkness. Realistically, a good rule of thumb (but not an absolute) is figure 1 foot for each LED. Therefore, if a camera has 30 LED’s then it probably can see about 30 feet. There are some newer LED’s called Cat’s Eyes, which have more power, but they are not very common. You would notice a Cat’s Eye by the extra large size of the LED’s. With respect to infrared quality it has more to do with the intensity of the LED's and the distance they cover. One thing to note is that infrared LED's do have a limited life since they are illuminating so they do burn out over time. Just because one camera has more LED's than another does not mean it can cast a longer distance, there are different strengths in the LED's. Unfortunately, again for the consumer it is hard to properly compare.

Bullet Camera

• When you want the camera to be inconspicuous but not covert
• When the camera is not within someone’s reach
• When extreme low light conditions are not a consideration
• For shorter to middle distances

NOTE: As bullet cameras are small the type of internal boards and lens is limited. Accordingly, the picture quality of the bullet cameras cannot compare with other more traditional cameras, which can have double layer boards and camera function controls.

Covert Camera

• Just as they say, these are meant not to be seen and come in all shapes and sizes from a wall clock to a sprinkler head or smoke detector
  

NOTE: It is important to check your local laws with respect to surreptitious recording. In some states certain types of covert cameras are illegal. For example, in New York State you are not allowed to install smoke detector cameras. With respect to recording audio, there are very specific laws, which vary from state to state. Some states require all parties consent to recording, while others only require a single individual.

Wireless Camera

• When connection to the digital video recorder is not practical
  

NOTE: Remember though wireless is just for the video signal, you still need a method to power the camera. Wireless cameras can be found in most styles. For the most part wireless cameras require a line-of-sight to function properly. Distances will vary depending upon the strength of the transmitter and receiver, what other devices are in the same spectrum, etc. Realistically, you are looking at distances of 100’ or less on affordable wireless equipment. There are external wireless transmitters and receivers that can attach to any standard camera and make them wireless, but the costs are incredibly prohibitive.

Pan Tilt Zoom (PTZ) Camera

• When you want live control of the camera and adjusting the manual pan, tilt or zoom on a fixed cameras is not practical
• When you want to set up a camera to tour the premises
• When you want to view several angles from a single camera
  

NOTE: Pan, Tilt, Zoom cameras cost anywhere from 5x – 10x the cost of a fixed camera. The Pan, Tilt, Zoom camera cannot record or see where it is not looking. You cannot pan, tilt or zoom after it has been recorded (this can only be done with a 360 degree camera). Making a PTZ camera wireless adds thousands to the cost. PTZ cameras can though perform various functions not possible with a fixed camera. You can control a PTZ camera and zoom in optically up to 36x and beyond digitally up to 12x giving zoom capabilities in the 100’s. The PTZ’s have intelligence and can be programmed to perform pre-defined tours and upon the event of an alarm the camera can swing to a specified location before continuing its tour. An operator can override and take control of the camera at any time.


CCTV Camera Categories:

Indoor vs Outdoor Cameras

Ostensibly, indoor and outdoor cameras are the same in terms of styles, sizes and shapes. The principle difference is outdoor cameras are at a minimum weather-proof.

While rain is a primary issue other considerations such as moisture, dust, sand, snow, frost and humidity need to be addressed. Accordingly, some cameras are equipped with heaters and blowers to counteract the elements, while others can be housed in outdoor enclosures for the specified purpose.

Outdoor cameras most likely have to address low light conditions for evenings. Accordingly, they either have to have infra-red or some day/night technology, which today are quite affordable.


Night Vision and Day/Night Cameras

For low light situations there are two possible camera technology solutions. If there is total darkness then the only possibility is infra-red or otherwise known as night-vision.

Infrared (IR) Radiation — electromagnetic radiation of a wavelength longer than that of visible light, but shorter than that of radio waves. The name means "below red" (from the Latin infra, "below"), red being the color of visible light of longest wavelength. The infrared portion of the spectrum has a number of technological uses, including target acquisition and tracking by the military; remote temperature sensing; short-ranged wireless communication; weather forecasting and for our purposes night-vision.

Infrared is used in night-vision cameras when there is insufficient visible light to see an object. The camera uses the infrared portion of the electromagnetic spectrum, sometimes referred to as thermal imaging. The radiation is detected and turned into an image, hotter objects showing up in different shades than cooler objects, enabling the camera to see warm targets, such as human beings and automobiles.

Day/Night — a sensitivity enhancement technology which improves light sensitivity of a camera by a factor of 2 for visible light and a factor of 4 for near-infrared wavelengths. It still cannot work in near zero light as will an infrared camera.

While both infrared and day/night technology sound expensive, both have become commercialized and are surprisingly affordable. The difference in camera pricing for one of these cameras versus a traditional camera is nominal.

The rule of thumb we like to use is if you walk the area where you intend for the camera to be and view it at its lowest possible lighting, if you can see with the naked eye, then the day/night camera should be fine. If you cannot see, then an infrared camera would be recommended.

CCTV cameras similar to your movie camera are rated in terms of “lux” for purposes of lighting. In addition to night vision and day/night cameras there are low light cameras, which are standard cameras with a low lux rating (0.1).