If you want to use your flash off camera, you will need a wireless flash trigger or PC sync cord. Using your flash off camera allows you greater creative control of your light and you can avoid some of the drawbacks of using a flash on your camera’s hot shoe. This guide breaks down the most important features to consider when choosing a flash trigger.
Topics in this Flash Trigger Buying Guide
| • Types of Flash Triggers • Transmitters, Receivers, and Transceivers • Compatibility and TTL • High-Speed Sync |
• Channels and Groups • Transmitter Range • Frequency Considerations |
There are two basic types of wireless flash triggers: Radio and IR.
Radio
Radio transmitters send commands to the remote flashes using radio waves. Radio signals can round corners and pass through objects; therefore, the camera and speedlights do not need to be in sight of one another and can be operated at a distance away from each other.
IR
IR transmitters send an infrared light signal to the strobe lights—triggering the flash with an invisible beam of light. When using IR transmitters and receivers, the two units must be “line-of-sight”—one visible to the other. IR technology existed in early flash triggers and is still in use today, but has been mostly replaced by radio systems.
Whether you need a transmitter, receiver, or transceiver depends on your setup. In general, you need a transmitter (trigger) that attaches to your camera’s hot shoe and a receiver that attaches to the flash unit. Some strobes have built-in receivers, so you might just need a transmitter. A transceiver is a combination transmitter/receiver—allowing you to use it either as a receiver or transmitter, depending on your setup.
Compatibility and TTL
High-Speed Synchronization (HSS) is a function that allows your camera to use a faster shutter speed with a flash for greater lighting control. Most cameras have a flash sync speed of around 1/250 of a second—where the camera synchronizes the flash of the strobe with the full opening of the shutter. If you want to use your flash at a faster shutter speed, to help balance ambient lighting with the flash for an optimal exposure, you’ll need HSS.
Some, but not all, flash triggers support HSS, usually through TTL communication between the flash and camera. This means your best bet is to get a trigger system that is compatible with your camera’s TTL protocol.
When using radio, your flash trigger transmitter and receiver need to be on the same radio channel to communicate. Many transmitters and receivers have multiple-channel capabilities to avoid potential interference from other flash and other electronic systems that might be in use nearby.
Grouping is a method that allows you to place one or more flashes in a separate section from other units. For example: You can communicate with and control two flashes together in Group A, while communicating with and controlling another flash in your setup separately under Group B.
Through the use of multiple groups and channels, you can synchronize a virtually unlimited number of lights to your camera.
Whether you are using IR or radio trigger systems, they will have a limited communication range. The limited range of IR systems is not often a problem in small studios but, for larger studios or expansive setups out in the field, be sure you are shopping for a transmitter and receiver that can communicate across your scene.
Most systems feature a range of around 328'. That distance might seem like overkill if you’re using your flash in a small studio, but know that the longer-range the system is, the more reliable the signal will be, even at short distances.
Depending on where in the world you are using your radio trigger, frequency interference can be an issue. Many flash triggers operate in the 2.4 GHz frequency band, which, depending on your location, can be susceptible to interference. The 340-354 MHz and 900 MHz bands are also popular and reliable.
We hope that this buying guide has allowed you to find your way to the purchase of the perfect lighting triggers for your photographic needs. If you have any questions, please post them in the Comments section and we'll give you a hand.
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