Fixed lens cameras have a set field of view and cannot be manipulated to produce a wider or narrower angle. These are generally found as 3.6mm, 4.3mm, 8mm, 12mm, etc.. The higher the number of the focal length, the more telephoto the effect. *However- this has nothing to do with the actual size of the lens itself. You can obtain a 3.6mm lens which can range in physical size from 1mm (on a micro pinhole type camera) to the size of a soda can (for much larger security type cameras).

Variable focus (or varifocal) lens cameras allow the user to modify the field of view from its widest/ most panoramic to the narrowest and most telephoto views that it is capable of. Some lenses provide a 4-8mm (widest at 4mm and most telephoto at 8mm)- whereas others may provide 5-50mm for a super zoom in ability.

Many are set up to interface with a variety of optional lenses. However, there are also cameras with built-in lenses that cannot be removed or replaced. The removable type mounts are referred to as "C" or "CS" mount because of the type/ size which is an industry standard. Many lens choices are available and the decision should be based on actual requirements for the application. For instance, if a wide field of view is required, there may be no reason to include a feature which allows a zoom to a tighter shot.

It should be noted that most varifocal cameras are not weatherproof and will require a suitable enclosure for outdoor use. However, we do carry these outdoor housings, including those with built-in heater/ blower. Also, we have an incredible weatherproof integrated PTZ camera available (DN-PTZ) which allows you to facilitate pan, tilt and zoom functions all from a SINGLE control- with all parts protected inside a weatherproof dome with thermostat controlled heater/ blower inside!

The zoom function (whether manual or remote) is inside the camera or lens itself. We do carry different cameras that integrate all 3 functions (pan, tilt and zoom) into a single control- in both indoor and outdoor versions.

Optical zoom is the traditional method of physically manipulating the distance between 2 lenses to create a different camera view. Digital zooming is a technique in which an electronic processor literally magnifies size of the pixels imaged by an optical lens. There are different techniques, but "grainy" appearance is typically associated with digital zoom, especially when the camera. Of cameras that have the ability to zoom (aka varifocal lens cameras), some are optical, some are digital- and some are both (such as our TV-C270)- which means that the mechanical lens movement and internal digital magnification are both taking place (22x optical and 10x digital = total 220x zoom capability). It should be noted that not all digital zooming technology is the same. We've seen all ranges from extremely poor to excellent and are quite pleased with the equipment we carry.