Closed-circuit
television (CCTV) cameras can produce images or recordings for surveillance purposes, and can be either video cameras, or digital stills cameras
Bullet Cameras: A bullet CCTV camera
is a wall-mount or ceiling-mounted unit that is typically designed for indoor
use, but can also be fill some outdoor applications. The camera derives its
name from its sleek, thin cylindrical shape. Many bullet cameras also tout
themselves as being waterproof. The camera is not typically designed to have
pan/tilt/zoom control but instead to capture images from a fixed area. The unit
is mounted pointing at a particular area.
Dome Cameras: A dome CCTV cameras get
their name from the dome-shaped housing in which they sit. These housings are
designed to make the cameras unobtrusive… not covert or hidden. Typical
applications are retail, where the camera is designed to be unobtrusive, but
visible. These units serve a dual purpose: “bad guys” will know the facility is being
watched and patrons will feel at ease knowing the facility is being protected.
Units that allow the camera to spin quickly within the housing are often
referred to as “speed domes.”
Discreet
Cameras:
It’s clock… it’s a smoke detector… it’s motion sensor. The real answer is none
of the above. These are just some of the disguises for covert cameras. Of
course, covert cameras can also be characterized by conventional cameras placed
in discreet locations.
Infrared / Night
Vision / IR Cameras:
These night-vision CCTV cameras have the ability to see images in pitch black
conditions using IR LEDs. In some cases they are for mobile applications.
Outdoor CCTV Cameras: The key to outdoor
CCTV cameras is the housing itself, which must be impenetrable to moisture, insects,
dust and other elements.
Day/Night: Day/night CCTV cameras
compensate for varying light conditions to allow the camera to capture images.
These are primarily used in outdoor applications where the security camera is
positioned for an outdoor parking lot, for example. In many cases, units are
dubbed as having a wide dynamic range to function in glare, direct sunlight,
reflections and strong backlight 24/7.
Varifocal CCTV Cameras: A CCTV camera with a
varifocal lens allows the operator to zoom in or out while still maintaining
focus on the image.
High-Definition
Cameras: Ultra high-definition CCTV cameras are often relegated to niche markets,
such as casinos. These give the operators the ability to zoom in with extreme
clarity (to look at poker players, for example, who might have something up
their sleeve). In the past, these cameras were tube-based analog cameras, but
today’s digital technology has displaced those older units. The cameras can
also transmit their images using HD CCTV.
Network/IP: These cameras, both
hardwired and wireless, transmit images over the Internet, often compressing
the bandwidth so as not to overwhelm the web. IP cameras are easier to install
than analog cameras because they do not require a separate cable run or power
boost to send images over a longer distance.
PTZ / Speed
Domes:
Pan/tilt/zoom CCTV cameras give the surveillance operator the ability to move the
camera left or right (pan); up and down (tilt); and zoom the lens closer or
farther. These are relegated to surveillance situations where there is an
actual live guard or surveillance specialist monitoring the images. There are
cameras that have automated pan/tilt/zoom functionality where the camera is
moving on a timed basis. These are many times used to cover a wide area with
only one camera, or to avoid poor light conditions, such as a setting sun. 
