Freebase(0.00 / 0 votes)Rate this definition: Imagism was a movement in early 20th-century Anglo-American poetry that favored precision of imagery and clear, sharp language. It has been described as the most influential movement in English poetry since the activity of the Pre-Raphaelites.
The Spring Trigger. A spring trigger is actually a small spring with a threaded end that replaces the hard trigger on specially made index-triggered releases. Because it bends when you pull it, the spring is very difficult to punch. Your only recourse is to keep pulling as you continue to aim at the spot you want to hit.
TTL triggers are triggers that are capable of communicating the hotshoe protocol so that features aside from syncing can be sent from the camera's hotshoe to the remote flash foot. If you look at the flash foot or the camera hotshoe, the pin/contact that's in the center of the square is the sync signal. That's the signal that tells the flash when to fire so that it's in sync with the camera shutters and that the light from the flash will be used for the exposure.