Although image intensifiers, regardless of generation, all utilize available light, they cannot see in certain situations. The following are just a few examples: in shadow, underneath leaf covered trees, in barns and out buildings, between piles of materials in a yard, inside cars and lorries, underground car parks etc. To summarize, if an area is pitch black with no ambient light at all no intensifier will be able to intensify light that doesn't exist. It is rather like playing a blank CD, you can turn up the volume as much as you like, but the amplifier can't amplify something that is not there. The principle with Night Vision Devices is exactly the same, and for this reason infrared lamps still have a vital role. Firstly, they are comparatively cheap, bearing in mind that they give incredible performance for under $200. They are therefore the cheapest way to get massive increases in performance, you would have the performance of a system costing several thousand pounds more. The only time you would hit a serious problem would be if someone else was using a scope, and the lamp advertised your position. Secondly, there is the problem of no go areas. An Infra Red lamp opens up these areas effectively, and for this reason you should consider having some sort of infra red illuminator to hand in case it's needed, or to assist the scope on a night when thick cloud restricts moon and starlight.
We now come to the various types of illuminator which basically consist of two options. Laser Illuminators and Infrared Lamps. Both are highly effective, but our personal recommendation is that you opt wherever possible for a lamp. As a rule, the range is greater, and in addition it will not generally damage the eye if you look directly at it, whereas some lasers can actually cause retina damage if you look straight at them. These lasers are what is simply termed in the industry as non-eye safe. A reputable dealer will generally know what is, and what is not eye safe on the market. For obvious reasons it is an area where certainty is crucial, especially if children are involved, as due to the fact that no pain is suffered, people can be unaware that they have damaged their eyes until it is too late.