The LED Lil'Greenie lights have some distinct advantages over other type of lights used for underwater lighting, advantages inherent in LED's. The information below was an answer to using a green light film, .on White LED lighting. But the information is relevant to the LED Lil'Greenie, a pure green LED underwater light that is my creation.
A white LED light uses a spectrum of Blue, Green, and Red LED dopants stimulate our eye retina cells of the proper amounts and processing steps to make an equivalent "white" light LED as seen by the human eye, a tri-stimulus condition that our brains integrate into white light.
Each of the 3 LED light components by themselves have a relatively narrow bandwidth. The green color component of the LED white light is the weakest of the 3. A green filter will allow most of the green to pass through, while mostly blocking the red and blue components. Compared to the white light, the amount of green passing the filter will be disappointing in comparison.
A green LED light is a different matter. This type LED is tailored to emit the maximum light possible for the same operating current, and is a pure green light with a very narrow visible spectrum band width. It only stimulates the green cells of the retina. As a bonus, the human eye is most sensitive to green colors, more so than any other color.
An additional bonus for LED lights is the highly directional light pattern generated by LED's compared to any other source of light used for underwater lighting. Most lighting applications try to spread out the light uniformly in all directions, and are very successful in that manner. LED lights in general require multiple LED's and angled mounts to cast the light in a desired direction to simulate indoor incandescent light usage.
But for our usage, we would like to have the light fan out like a pizza pie. Far out distance in the horizontal direction, but a thin, narrow vertical thickness.
Then we can place the light far below the surface without really illuminating the catch, and still see a strong contrast between the catch and the light. In fact, a stronger contrast than would occur with the the fluorescent or halogen type lights. The Shrimp floating above the light would be little disturbed by the LED light itself. You would see more contrast of the shrimp or bait than with other type lights.
And this is good, a higher catch rate is possible.
One other factor - As humans age, so do the retina cells in our eyes. particularly the sensitivity of the eyes to see in dimly lighted conditions. The night vision deteriorates as we age, so ti takes more light to stimulate the eye to respond - the threshold of illumination increases, according to my retina specialist. It's what causes elderly patients to give up night driving.
The LED underwater light disk will still stimulate the retina cells to see more contrast, as the image of the shrimp or bait is not illuminated , but is backlighted and therefor gives stronger contrast, stronger than with other light types.
