Friday, May 29, 2009

Salmon Eyesight - Measuring Color Levels and Range Underwater

Like we mentioned a few weeks ago, alot of our experiments and "fun stuff" we do on the river in between fish is to figure out what colors the fish can see - especially down DEEP (30 feet or more).

This will give us the advantage of picking the best lure combination, that other anglers don't have - like the one shown here.

We've collected video using underwater cameras, digital cameras in cases, and even vacuum-sealing cameras, like this! The goal is to measure the actual color at various levels, with different water clarity - when the Columbia is running brown, or green.

We have other experiements putting lights and LEDs on our lures, too - so we need to know how far the colors are visible down deep. It isn't enough to know how much color from sunlight is visible.

Here is the camera ready to head to the bottom. When we collect the video, we can use Photoshop or other applications to compare the pixel color values, compared to video at the surface.

Here is another circuit we rigged up to measure the actual amount of color detected as we get deeper underwater - both from sunlight reaching down into the water, or from a spotlight under our boat (never heard of that one, huh?) or from LEDs on the lures or dropline. The circuit here measures the green, blue, and red light levels, displays them, and records them into memory for use on the PC later.

Its all about getting the data to ultimately get the fish in the boat! ... and to keep us from getting too bored when the science fails us. Here's some video looking at the different colors on a Simon/Wobbler down to only 6 feet of depth. Not much visible to the naked eye... but what about Ultraviolet light??? Stay tuned!