Optics and bio research hi yall! im doing a neuroscience research on the circadian behavior of different species of fishes, and i need a device to measure activity levels of fish under different light conditions. one of the mostly used method is to have a light source (IR or something else) and a receiver and measure when the light beam breaks due to fish's movement. I have a couple questions as to the setup, and I need yall's help! the questions are: 1. how should the setup be? any recommendations for type/brand of detector, etc? 2. which is better, IR beam or any laser beam? 3. is there a better way to detect the movement of fish? 4. are there any computer programs available to take the data? i will really really appreciate your comments! thank you!!!