Test the range of your Radio Triggers with Triggertrap Mobile

Have you ever wondered what the range really is on your radio triggers? Triggertrap Mobile lets you put this to the test using the DistanceLapse mode! Yesterday our photographer buddy Alan Langley was showing off his fancy new flashes with built in radio triggers, with an advertised working range of 100 meters. I simply didn’t believe that these cheaper flashes and triggers would work at 100m, so we set out to test them.


Trying to measure a set distance without a trundle wheel or range finder could have been tricky, but the DistanceLapse Mode on Triggertrap Mobile did all the hard measuring work and the camera triggering work for us. Triggertrap Mobile's DistanceLapse mode uses GPS to fire the camera at a set distance interval. This gives a really accurate way of measuring the distances, and also gives an interval so you can keep going until the flash stops firing. We set up on a pier that is about 300 meters long. As it's totally flat you can maintain a clear line of site to the flash. So we started the test at 20 meters... Then very soon hit 150 meters...


Then eventually ran out of space at 300 meters ...


I'm just glad I didn't put any money on the flashes not meeting their advertised spec. It's safe to say I would have lost it! If you want to have a go at this yourself, here’s how to go about it:


  • 1 Flash
  • 1 Light Stand
  • 1 Radio Receiver
  • 1 Radio Transmitter
  • iPhone 5s with Triggertrap Mobile in DistanceLapse mode
  • Triggertrap Mobile Kit
  • 1 Camera & wide angle lens

The Setup

  1. First, set the camera up so that it gives a reasonable exposure at the maximum sync speed (in this case, 1/200s, f/8 at 100 ISO).
  2. Set the camera to manual focus at infinity and then connect the Triggertrap Mobile Kit to the camera and phone.
  3. Next, set up the flash. We used a stand but someone could hold it if you don’t have a stand handy!
  4. Make sure that your radio receiver is turned on, and also set the flash to a high power (we used full power) to make sure you can see it!
  5. When you’re ready to start testing, open up the Triggertrap Mobile app and open the DistanceLapse mode. Set the distance to 10m and then hit start. Before you start moving, allow the GPS to settle.
  6. When you’re ready to go, point the camera at the flash and start walking back. You’ll know that the camera fires every 10m so by counting how many times it fires the flash, you’ll be able to calculate the range - unless you run out of space that is!