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.
Performance Specifications 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!
Copyright 1999, BoatUS, all rights reserved.
This article is reprinted with permission from
BoatUS, who is solely responsible for its content.
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