A big factor when determining what security cameras to use in any application is usually their nighttime capabilities. Lets face it, if you’re not in a constantly lit warehouse or a place with 24 hour lights, then you have to consider both the low light and IR capabilities of the security cameras you’re going to use. Of course nowadays there are a number of extremely high powered IR options on cameras, but that isn’t always enough for a full image. This is where an external IR illuminator can be a savior!
With an external IR illuminator you have the ability to place an infrared source in multiple locations near your camera to provide even more coverage then your camera might have. Your camera will then be able to see additional space and have a brighter image then it would of had normally. Since the camera is already IR sensitive it will have no problem picking up the new IR source.
When you’ve finally decided you want an external IR source all you really have to concern yourself with at that point is the range you want to achieve and whether it needs to be weatherproof or not. One other consideration to make as well however is to make sure that the infrared wavelength of the external emitter is the same as your camera. Usually this will mean either 950nm or 850nm.