Nick,

I've got the LUA shutter script working on my A495, and have written an Arduino sketch to control it and serve as an intermediary between the APM and the camera. I've been busy putting together the airframe, a Ritewing Zephyr II, and haven't had a chance to make a post here on my progress. I need to get back to working on the script to get more functionality now that the airframe is almost done. I'm going to set it up so that it will go into "review" mode after takeoff and before landing to retract the lens. I need to take a look at the current Planner to see what other Mavlink functions are now available. The last release I've downloaded, from a month or so ago, had some exciting camera options, and what looked like a function to automatically create a route based on the camera parameters and the amount of overlap is desired. I've got a servo setup for roll stabilization, and think that I might be able to use another free channel to send a PWM lens retract command to the arduino, which would then send a pulse to the camera to go into review mode. I've also been working with a Sony block camera, and looking at the currently available Mavlink commands in the APM firmware, it looks like they are maybe working on options for things like shutter speed, zoom, etc that could be implemented either through an arduino sending commands to a point-and-shoot with CHDK, or to send serial commands to a Sony block camera. 

Anyway- I'll make a post in 3 or 4 days detailing my build and what I'm doing with aerial photography and photogrammetry...

Cheers,

Seth