Dr. Charles H. Mazel: Fluorescence
Fluorescence is the process of absorbing one light wavelength of color, and being able to reemit the same light at a different wavelength and color. It's like black light posters underwater, but instead of UV light, were using blue light. Regardless, it's the same process. When were looking for fluorescence we need a source of light to stimulate the organism. These things don't glow on their own. We can demonstrate this by using a really high intensity dive light, technology similar to that on the submersible. It takes a while to come up to full strength, but it creates a really bright white light. This white light has a lot of blue in it, and we can take advantage of this by slipping a blue filter over this light. This converts the white light source to a blue light source. Now if we went around shining this light on things, we'd just see the blue spot. We needed to block that blue to see the fluorescence. As a diver, you would wear a yellow filter that you would wear over your mask. In a submersible, we would simply wear a pair of glasses. For the sub, we have glasses that are comfortable to wear. You can sit back in the sphere and wear these yellow tinted acrylic glasses and see what the blue light is shining on the sea floor, and then alert the sub driver when you see something, a little to the left, a little to the right. In order to have the sub cameras see this, we slip on hefty filters that fit over the lights of the submersible. A safety line so that if it accidentally falls off, it doesn't drop to the bottom of the ocean. This turns the bright white lights of the sub into bright blue lights. For the camera, we have a yellow filter, just like the glasses. We have them custom fit to the camera. Underwater, the sub's manipulator arm can swing the filter into place. This allows you to perform white light photography and fluorescence photography. When we shine the blue light over the bottom, you really cannot tell if an object is fluorescent or not. You really need the yellow filter. When we pass the yellow filter over the camera, we see that the blue spot goes away, and you can see the glow from whatever you are looking at.