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Step 5Using The Photo Trigger
The idea is to set the thing up so that the beams cross where you expect some action to take place. For example, if you want to shoot a hummingbird at a feeder, or a bird entering or exiting a nest, set the frame up with the crossed beam point right where you want it. Then set up the camera pointed at the target and preset the focus, exposure, and white balance (this will minimize the shutter lag time). Test the beam alignment to make sure that BOTH beams are aligned correctly- this is done by waving your hand through each beam individually then through the target area. The LED should light and relay close only when both beams are interrupted. Now set the operating mode- either continuous or pulsed and go away.
You have to know a little about the behavior of your target to get best results. If you want to shoot something that moves fast, you have to take the camera and controller delays into account to predict where the target will be after it interrupts the IR beams. A humming bird that is hovering in one place can be shot right where the beams cross. A bird or bat that is flying fast might be a couple feet away by the time the camera takes the picture.
The pulsed mode allows cameras that don't have a built in continuous shooting mode to take multiple pictures as long as the beams are interrupted. You can set the pulse frequency as high as 10 Hz, though there aren't many cameras around that can shoot that fast. You'll need to experiment a little to see how fast your camera can shoot.
The camera connection is via a normally open relay contact so you can connect a flash instead of a camera. Then you can shoot in the dark by propping the shutter open and using the controller to fire a flash unit either once or multiple times when an object (a bat, maybe?) breaks the beams. After the flash is tripped, close the shutter. If your flash can keep up you can make some cool multiple exposure shots by using one of the pulse modes.
You can accurately locate the point where the beams cross by attaching some elastic thread to the optical heads. For some targets, that is where you will point and prefocus your camera. The photos below show a Lego man falling through the beams. I dropped him from a couple feet above the beams and you can see he has fallen about 6-8" below the beams in the time it took for the beams to be broken, the relay to close, and the camera to fire. This camera was a Nikon DSLR that probably has small shutter lag when prefocused and exposed. Your results will depend on your camera.
The prototype is now in the hands of the friend who took these pictures (my camera needs to be modified to use remote shutter release). If he produces some more artistic photos using this device I'll try to post them here or on my web site.
Have fun!
You have to know a little about the behavior of your target to get best results. If you want to shoot something that moves fast, you have to take the camera and controller delays into account to predict where the target will be after it interrupts the IR beams. A humming bird that is hovering in one place can be shot right where the beams cross. A bird or bat that is flying fast might be a couple feet away by the time the camera takes the picture.
The pulsed mode allows cameras that don't have a built in continuous shooting mode to take multiple pictures as long as the beams are interrupted. You can set the pulse frequency as high as 10 Hz, though there aren't many cameras around that can shoot that fast. You'll need to experiment a little to see how fast your camera can shoot.
The camera connection is via a normally open relay contact so you can connect a flash instead of a camera. Then you can shoot in the dark by propping the shutter open and using the controller to fire a flash unit either once or multiple times when an object (a bat, maybe?) breaks the beams. After the flash is tripped, close the shutter. If your flash can keep up you can make some cool multiple exposure shots by using one of the pulse modes.
You can accurately locate the point where the beams cross by attaching some elastic thread to the optical heads. For some targets, that is where you will point and prefocus your camera. The photos below show a Lego man falling through the beams. I dropped him from a couple feet above the beams and you can see he has fallen about 6-8" below the beams in the time it took for the beams to be broken, the relay to close, and the camera to fire. This camera was a Nikon DSLR that probably has small shutter lag when prefocused and exposed. Your results will depend on your camera.
The prototype is now in the hands of the friend who took these pictures (my camera needs to be modified to use remote shutter release). If he produces some more artistic photos using this device I'll try to post them here or on my web site.
Have fun!
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