Night Vision Systems
Revised by BoatUS editors in June 2012
Night vision technology allows you to clearly distinguish objects at night, even at distances of up to several hundred yards, in the absence of artificial light. You can see boats, people, buoys, jetties, shorelines, channel markers, and anything else that you would only see as indistinct shadows with the naked eye. It's important to understand that night vision systems amplify existing light and will not operate in the absence of all light, i.e. a cave, sealed basement, etc. Some models have infrared which sends out a beam of light that is multiplied. This allows for viewing in complete darkness and is particularly good for locating buoys with reflectors attached to them.
A Brief Overview
Night vision systems provide electronically enhanced viewing. When you use a night vision system, you are not actually viewing the scene before you, but rather a video image of that scene through a video camera with an extremely high sensitivity to light. The system picks up the available light reflected from the objects being viewed, and converts the radiant energy of the light to electrical energy in the system. The electrical charge then becomes an accurate representation of the scene being viewed. The FLIR systems, which have taken this technology to a much higher level, should be investigated before you buy. It’s also important to know that a good pair of binoculars can greatly increase night vision without the technology referred to here simply because their construction gathers ambient light well.
Night vision systems vary widely in performance, so it's important to recognize some basic performance criteria. The three most commonly cited specifications:
- Light Amplification refers to the amount of light multiplied.
- Sensitivity is the light threshold at which the system will operate, the relative darkness if you will, under which it will perform.
- Resolution is an indication of the amount of detail you will be able to distinguish through the system.
Although this is a simplified explanation of night vision systems, it helps give a working knowledge of how these systems work. If you do any night time boating, do yourself a favor-don't be left in the dark!