I am reading a lot about the flashes and the different types.
I am still not 100% sure if the 550D is E-TTL A-TTL or any TTL.
My speedlight (in other post/thread) is probably tooooo old, but I am sure it used to work with TTL on my old AE1-P. But that is "so yesterday" is seems.
Anyway, reading and looking there are those kind of flashes then there are the FP (high speed) flashes which work at ANY speed.
I have also read about cyncing the flah to the curtains. First, second or both.
First curtain flashes when the shutter opens.
Second curtain fires the flash just before the shutter closes.
Both, does two flashes. One when the shutter opens and one when it closes.
I have also read where you open the shutter, fire the flash and hold the shutter open for 'x' seconds after that. It was called "Dragging the flash" but not sure if that is THE term and/or if/how I could do it on the 550D.
Anyway, this "FP" system sounds interesting.
Other than setting up lights everywhere they are needed and leaving them on for how ever long it takes, is a lot of effort/energy.
CAN/COULD I set up a system using the FP signal to "fire" the flashes/lights when the shutter button is pressed?
That way I can do what I want, set the lights (rear ones, side, etc.) have anothe button to activate the lights so I can see what I will get, then when happy, "Click" take the image and have the lights flash then.
This would probably mean getting a hot-shoe thing to connect to the camera's flash connection and build some electronics. Not a problem - unelss it involves extreme building/design.
But if they are only discreet signals/voltages - not an entire sequence of pulses - then it shouldn't be that difficult.
Anyone every done this?