Video Tracking for Behaviour Research
Camera and lighting, done right
Nine tracking headaches out of ten start at the camera. Fix the set-up and the software has an easy life.
Where the camera goes
Directly above the arena centre, so the image isn't skewed. Large pools in low rooms may need a wide lens.
Frame rate and resolution
For rodents, 25 to 30 frames a second is usually plenty; fast behaviours and larval fish may need more. Aim for the animal to be at least a few dozen pixels across.
Light
- Even, diffuse light with no hotspots on the water.
- Infrared lights and an IR-sensitive camera for dark-phase tests.
- Identical lighting across animals and days. It changes behaviour as well as tracking.
Contrast
Match the arena to the animal: white floors for dark animals, dark floors for albino ones. In the pool, opaque water hides the platform and helps the tracker in one go.
A 60-second check before every session
- Is the whole arena in view?
- Is the calibration still right?
- Does a quick test track run with no lost frames?