What are Infrared Illuminators?
Infrared illuminators for night hunting are nothing other than a typical torch, with an LED (light emiting diode) in it. The LED however doesn’t emit visible light, but rather uses infrared light that is not visible to the human eye, or to animal eyes. The wavelength of that infrared light is either 850nm or 940nm (nm = nanometres).
What is the difference between the 850 and the 940? The 850 is referred to as the long range IR light, whereas the 940 is referred to as the stealth or invisible infrared illuminator. Both are in essence invisible. The only difference is that the 850 will light up the objective lens, and you can see a red shimmer, whereas the 940 will only light up the actual LED itself. So all you see is a tiny dot within the torch.
What this means is that if you’re doing close range shooting (<50mtrs) at night, you’ll be better off with the 940nm. If you want to do long range shooting, you’re better off with the 850nm because it will throw light further down range. You will perceive it in the device as a stronger torch when you look through the device, so with that you can get ranges up to 250 metres with a typical IR illuminator.
There are some infrared illuminators called Sniper Hog Lights. These illuminators have a reach or range up to a kilometre. Realistically you won't be shooting past 300 metres because the resolution of your digital night vision device will get too pixelated and you won't want to take the shot, or you won't be able to tell what you’re shooting at. The illuminators that are provided with the devices will not work for you over 200 metres very well. Even at that distance it will be relatively hard to manage.
One more thing, when you look through a digital night vision device with an illuminator, it shines infrared light out. It lights up an object and gets registered by the device and the device produces an image on the display. If you have objects in front of you, like grass, trees or bushes, and the target is behind that, it can "white out" the image. When you use an 850nm illuminator for example, and you power it up all the way in order to light something up at 200 or 300 metres, what happens is that the objects in the foreground get really, really bright to the point where it brightens out your image, and you can’t see anything past that point. It’s something to consider, where you want to decide if you want to use digital night vision or go into thermal vision, which doesn’t have that limitation.