Radio and infrared triggers
Last but not least are radio and infrared triggers. Both of these go on your camera’s hot-shoe but only the latter need to ‘see’ your speedlight. Another difference between radio and infrared triggers is that you won’t need a receiver unit for the speedlight when using the infrared trigger.Using a radio transmitter and a receiver is probably the most versatile way to trigger a speedlight. As the name says, it uses radio frequences and therefore the signal can travel long distances (often up to or over 100 m/328ft) and it passes through obstacles. Therefore, there is no need for a camera and a speedlight to be in the line of sight. We will talk more in detail about radio triggers in one of next articles.