Previous experiments on this blog used a breaking laser beam to trigger the camera. While this approach has some advantages there are a few major disadvantages too. The main disadvantage is the requirement to set up and accurately align lasers around the target. In certain situations this isn't an issue, but in many cases it is completely infeasible. The goal for well over a year now has been to design a module that will slip over the eye piece on a DSLR and will only fire when something changes in the field of view. The idea being you set up your camera with whatever lens you want, frame up and focus on the target (an empty perch for example) and as soon as the picture changes, the camera fires. In theory this sounds like a simple problem to solve but in reality I've encountered many headaches that have stopped me building the ultra low latency system I envisaged. Rather than allowing these roadblocks to halt all progress though I've decided to work on a simpler syst