Upon careful inspection, that is about the only difference. Thanks for the 'shot' comment. My project (I've called it DEBE(does everything but eat)) is an interface to a Canon DSLR and strobes. DEBE can now: 1. Detect sound and fire strobes, & trigger camera simultaneously.
2. Detect sound and trigger camera and add delay for strobe (those pictures of a glass shattering).
3. Detect presence and fire, trigger using the ultrasonic transceiver.
4. Interval fire camera (timed sequence shots, like a plant growing or a season changing).
5. Fire camera and flash by proximity with a 'mass detector'
6. Fire camera and flash by magnetic reed switch (photograph moving objects that I've tagged with a magnet)
I have used the Arduino Protoshields as Radio Shack was carrying them, now they are on clearance as they move to lower their image even further.