Zoom refers to an adjustable field of view. Cameras may have manual zoom with a varifocal lens or remote zoom with a powered zoom lens. Some DVR video recorders also have the ability to change the monitoring field of view and zoom in or out on selected areas of a recorded video image.
What is a varifocal or zoom lens camera?
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!
Do I need to manually control a zoom lens type camera- and how?
It all depends on the camera. Most variable focal (varifocal) "zoom" lens cameras actually do require the user to set the optimum adjustments by hand. Some zoom cameras have the ability to control the zoom and focus the camera with a wired remote controller from 125' away. Camera is also available integrated into a pan/ tilt unit to control all functions with a single remote.
Can I pan & tilt without a zoom camera- or vice versa?
Absolutely. In fact, many systems referred to as PTZ are actually the combination of a pan - tilt housing with the addition of zoom camera. However, there are also truly integrated PTZ systems in which the user can choose one or all functions.