Color is always a challenge at night or in low light levels. This is a two fold problem...
The first is that colored light does not reflect at the same intensity as white light. This is basically because color is usually a very narrow wave length of light while white is a total and equal combination of all colors. If you think of white light as a bundle of human hairs. Each strand would represent a single wave length or color. Now think of low light color reflection as the difference between a single hair (one color wave) and ten thousand hairs bundled (white light)... Which one would be more easily noticed? The ten thousand hair bundle (white light) of course.
The second problem with color at night is caused by an infrared (IR) filter in the color camera. Because of the color chip's extreme sensitivity to IR light, all color cameras have a permanent IR cut filter installed to block out IR light. If we didn't do this and because IR light is red, all of your color images would come out in varying shades of pink. Because of this IR cut filter, two things happen, up front with color cameras....
1. They tend to be less sensitive in lower light
2. You cannot enhance your outside lighting with Infrared light because the color camera does not see IR.
Consequently, if you are going to enhance your nighttime lighting, you want to use a light source that is white and made up of an even spectrum of colors. This is the only to insure proper color reflection in the dark.
As a final recourse however, you don't need to be left in the dark... This is the 90's and the technology that is coming out is breaking all of the rules. At the end of the day, anything is possible if you have the bucks. I have recently come across a low light level color camera that blows everything that I have ever seen completely out of the water. It is the "Fukurow Eye". This camera comes in three models; TVC-3000; TVC-100S; and the TVC-50. They range in cost somewhere between four and ten thousand dollars. These cameras have sensitivities as low (or lower) as .0003 foot candles...and they produce incredible, real time color at these ranges. And they said it couldn't be done. This sensitivity is almost as good as a Black/white intensified camera that is designed to work in half moon light.
Understand please, that I do not sell, distribute or promote equipment. This is primarily because I represent some twenty five different manufacturers from a service perspective. I don't want to put one over the other. However, these cameras are extremely unique to the world so I don't have a problem referring you to a source for more information. The person to contact about this camera and ultimate demonstration or distribution would be:
Mr. Colin Howgill - President
Video Watch Services
4401 East West Highway
Bethesda MD 20814
Main: (301) 654-4397
Fax: (301) 654-0115
When you contact him, give him my name as a reference. These cameras are definitely worth looking into prior to a quote or a final decision on what to use in your outside, low light, color applications. At any rate, I need to fly for now. Thanks for the letter and come back at any time. I am in your service.
