1. Ecology of Vision Group, School of Biological Sciences, University of Bristol, Bristol BS8 1TQ, UK
2. Azul Optics Ltd, Henleaze, Bristol BS9 4QG, UK
3. Sensory Neurobiology Group, Queensland Brain Institute, University of Queensland, Brisbane, QLD 4072, Australia
4. Biosensors Lab, Electrical and Computer Engineering, University of Illinois, Urbana, IL 61801, USA