i'm setting up a red one to be triggered by the cycles of a machine, with each cycle of the machine's motor, a relay trips the trigger to grab a frame. generally it is working but the timing is terribly uneven which makes the frame grabs useless.

i bought a cable from red with flying leads that ties into the 12v/4pin port at the back of the camera. per instructions from red support, i set my relay to short the yellow (gpi) wire with the white gnd wire. i think i have that right. not in the studio to write this. in any event, it does work. when first testing, though, i simply touched the two wires together and found, even then, that there might be delays between the shorting of the wires and the grabbing of the frame. on the other hand, sometimes it might grab frames very quickly. the result of this is that, as the machine cycles continuously, it rarely seems to grab frames at the same time in the cycle. the machine has moved on towards its next cycle. it does grab within a single cycle, just never at the same place within that cycle. the timing is pretty critical on this.

any thought on what might be wrong?