Typically, getting your camera to fire is easy. You plug in the correct camera-specific triggering cable to the camera triggering port of the ST4/ ST4.3, the other end to your camera and set up a basic timelapse shot on the spectrum.
When the ST4 isn't triggering shots, typically users aren't sure where to start. Often, the ST4 is thought to be the root cause. While this can be the case with a physically broken camera port on the ST4, this is only something we have seen a couple times from drops and physical damage. The issue is much more likely to be your camera settings or the triggering cable. This article will help you figure out if your triggering cable and camera are good or bad.
How SMS camera triggering works for most DSLR and mirrorless cameras
Thankfully most camera manufacturers followed a standard where all that is needed to trigger a shutter release is 3 control lines from the camera. These are a shutter, focus, and ground signal from your camera.
Most cameras will fire when the Shutter signal is pulled to the Camera ground. Some cameras require both the Shutter and Focus pins to be pulled to the Camera ground to fire off a shot. This process of connecting these signals needs to happen for typically a very short period of time 20ms or so, but 100, 250, or even longer is sometimes necessary for the camera to fire off a single shot.
How to test that it is working correctly without the ST4 / ST4.3
- Power on your camera and make any menu changes internally for it to accept external triggering from the cables. Most camera vendors don't turn this off, but some can.
- Set your camera up for full manual with Autofocus off.
- Check that your camera immediately responds to the manual shutter button trigger. If it takes some time and your lens is seeking focus for a period of time, then really figure out how to turn off your autofocus as we requested in step 2. Your camera needs to be ready and fire that shot immediately. If not, you have a camera issue that needs to be resolved before you continue.
- Hook up the shutter cable and leave the ST4 end (2.5mm TRS cable end that looks like a mini stereo connector) unconnected
- Take aluminum foil and connect all three visible connectors of the ST4 end of the triggering cable together.
- Your camera should fire.
- If it does, the ST4 should trigger your camera as well from the camera port. Make sure you are using the Camera port and not the
- If it doesn't then you either have a bad cable or a bad camera setting where the ST4 will not be able to trigger your camera.