Here, we generally talk about strobism and using a flash with radio transmitters. We prefer radio because of how reliable they are, but they’re not the only option. For years, many photographers have triggered flashes and strobes using infrared transmission.
What’s infrared? Basically, it’s another way of triggering flashes to go off and usually requires you to use another flash. There are also limitations but in most situations it’s pretty reliable and it gets the job done.
How Does Infrared Triggering Work
To get Infrared Flash Triggering working you need two things in different combinations:
– The pop-up flash on your camera and ideally one or more hot shoe flashes of the same camera system
– The pop-up flash on your camera and at least one fully manual hot shoe flash
– The pop-up flash on your camera and at least one monolight. Most these days have an infrared sensor.
– Two or more fully manual hot shoe flashes with a slave sensor.
If you’ve got these then we can start getting to work.
Almost every flash has a slave and master functionality. The flash that will not be attached to the camera will need to be set into slave mode while the one of the camera (or the pop-up flash) will need to be set to infrared transmission or wireless master control.
Once that’s done, you’ll notice a blinking red sensor of some sort on the front of the flash set to slave mode. This sensor needs to face the master: which in this case is either the hot shoe flash or the pop-up flash. Once the master flash goes off, it will trigger the slave to go off as well.
Now here is where things get a bit more complicated: If you’re using a flash of the same system type, you can typically also set the master flash to not affect the scene at all. So that means that your settings can either be:
– The master and slave flashes both affecting the scene.
– Just the slave flash affecting the scene but no master affecting the scene. The master will solely be just for triggering the slave.
It’s really that simple. An extra bonus is that when the camera system and flash systems are all the same, the power levels, groups and ratios can all be controlled from the camera or the master flash.
What are the Limitations?
While infrared transmission is a simple, out-of-the-box way to actually trigger flashes and do strobist work with ease, it’s an inherently flawed system in many ways.
– Your flashes need to have line of sight of one another. Meaning that if one flash is in a softbox or a beauty dish, the setup may not work.
– Infrared transmission can only be done with the flashes around 15 feet or so away from one another
– Infrared triggering is highly unreliable outside in the sun due to all the infrared waves going around to start with. But at night, you’ll have much less of a problem.
– This method tends to drain battery life much faster
So what’s the good part? With radios, you need to buy a new radio system if you go into another country because it otherwise interferes with the transmission and effectiveness. For example, PocketWizards from the US won’t work in Europe. Conversely, infrared transmission works anywhere in the world because the entire setup is localized.
When Should You Use it?
In all honesty, we’re going to tell you to go for radio transmission whenever you can, but infrared can be done at times with certain situations.
– If you’re just looking to get into strobist photography and off-camera flash work, then start with infrared transmission until you feel limited.
– If your radios aren’t working.
– If you’re shooting at night or indoors with the flashes all being very close by to one another.
Otherwise, again, go with radio transmission.