I modified a generic Nikon IR camera trigger. I want to use an Arduino to make this work so I can attach sensors and / or bluetooth communication. Bluetooth has significant advantages over IR. It works over greater distances in strong sunlight and through obstructions such as walls, vegetation etc... I posted the information here as it is an ongoing project to develop Arduino controls for my Nikon camera. (my specific camera is D5100).
For information I updated this with some code so The Nikon now triggered by an SRF05 sensor.
Cheers