How to use flash triggers to photograph moving objects
Capturing movement photography can be a time consuming and frustrating process, and freezing that perfect moment often requires split-second timing.
So how do we capture those decisive moments accurately and precisely? I’m going to share my top tips for photographing motion and explore what wireless flash triggers we can use to get the perfect timing for our shots.
How to photograph moving objects
Photographing motion can be great fun, but it can also be very challenging. Timing is one of the trickiest parts of photographing moving subjects — 1000th of a second early and nothing has happened or a 1000th of a second later and it’s all over, the moment is gone and you’ve lost the shot.
But before we even get into capturing motion, there are a few other considerations and techniques that will help you get the best results.
Next, think about the techniques required for these different effects. If you want blurred motion, your camera settings are an important consideration, particularly the shutter speed.
In the moving bodies live show I created different motion effects as I photographed dance-style portraits, including one which used continuous LED lighting to create motion blur. I then showed another example where I combined LED and studio flash lighting to capture the motion blur while also freezing some of the movement.
To freeze motion, it’s less about your shutter speed and more about the flash duration — something many new photographers get confused about.
With natural light, it’s simply a case of using the fastest shutter speed possible, but if you’re using studio lights, a fast flash duration is essential.
Speedlites are also capable of fast flash, but they don’t have the same power output as studio lights, so you might need to group a couple of flashguns together to get enough light.
Once you’ve figured out what effect you want and the lighting you’re going to use to capture your image, pre-determining your focus is a good next step.
Often the autofocus on your camera isn’t fast enough to track and focus on a moving subject, so the best way to overcome this is to pre-set your focus manually on a spot where you expect the subject to be or the decisive moment to take place.
Lastly, it’s a good idea to finalise your lighting setup before you start shooting. This might involve temporarily asking your subject (or, even better, an assistant) to stand in for some test shots. If you’re photographing products, use a stand-in alternative or something with similar textural properties to give you an accurate idea of what the lighting will look like.
Capturing the decisive moment
I’m known for shots that often feature decisive moments and action, but capturing those shots can be tricky and sometimes you need specific tools to help you do the job.
Whenever I shoot motion photography, whether it be of people of objects, I make sure to use the mirror lock-up feature to minimise any delay time when taking the picture.
I explain how this works and the advantages of using this technique in the video, but even with this sometimes our human reaction times are not always quick enough to do the job accurately. This is where triggers come in.
Triggers are devices that are used to fire our flashes or our cameras at a very precise moment in time, and by using certain techniques such as delays, lasers, or sound activation we can utilise the power of these devices and their faster reaction times.
There are many wireless flash triggers on the market and I’ve used several different ones in my time. Depending on what I’m shooting, I use different models for different purposes and sometimes I even still do it by eye because it’s the most fun.
Let’s start with basic sound triggers. These can be found as Apps for your smartphone and with a simple kit cable release, they utilise the microphone in your phone as the sound trigger.
Sound triggers usually feature a delay time, which allows you to specify how long the trigger should wait before activating the camera shutter after it has received the noise.
Although useful, sound triggers don’t work for every scenario — maybe the speed of sound is too slow, or maybe the objects you’re shooting don’t make any sound.
How to connect a sound trigger
With sound triggers, your phone serves as the microphone. You connect this to your camera using a cable plugged into the headphone jack. Most apps allow you to control the delay time, but you can also do this by moving your phone closer or further away from the subject (depending on how long the cable is).
Miops flash triggers work slightly differently in that they offer a self-contained unit that allows you to use one trigger in different modes.
CASE STUDY: Splash photography using sound triggers
In this video, you’ll see how I use a sound trigger to capture a splash image of ice falling into a glass of water.
Lighting-wise, the setup was incredibly simple — just a single speedlight through a DIY modifier of black card and diffusion material.
In this case, the sound trigger worked perfectly as the camera was triggered as soon as the ice hit the water (or the glass, in many cases).
A further advantage was that by using the sound trigger we increased the number of shots captured at the right moment because without the sound trigger it would have been a matter of guess-work and lucky timing.
Laser triggers are great as they allow you to use pretty much any laser pointer and aim it at the sensor on the trigger. The trigger is then activated once the beam of light is broken by an object.
One of the advantages of laser triggers is their accuracy and precision, as you’ll see in my tennis racket product shoot.
However, they can also be tricky to set up and can cause problems when it comes to colour cast if you’re using a slower shutter speed.
How to connect a laser trigger
Like sound triggers, laser triggers are fairly easy to set up. The difference is that instead of using your phone, laser triggers require a dedicated flash trigger unit that has a lens-sensitive diode.
You would then aim any laser pen into this diode. Once the laser beam is broken, the camera is triggered and the flash fired.
As with sound triggers, you can manually control the delay time to capture the exact moment you want.
CASE STUDY: Tennis racket shoot using laser triggers
The final image shot for our tennis racket product photography class was captured using a simple laser trigger setup.
Initially, I tried using sound triggers but the noise created by the ball hitting the racket wasn’t sufficient.
The laser setup meant I was able to direct the ball through the laser beam and position the laser at exactly the right distance with a very small delay time, allowing me to execute the shot exactly as I intended.
Other triggers can be activated by using light or lightning, and others by breaking an infra-red beam — these are common in wildlife photography as the beam battery life is longer and invisible to animals. Others can simply be used as a remote control over a long distance.
The trigger you choose depends entirely on what you’re shooting. I often use Miops triggers as they work with all camera types, but there are others such as Godox or Yongnou available too that you could use for Canon, Nikon or Sony cameras.
You don’t even need to buy a trigger, you can create your own DIY flash trigger solutions, as I explain in the video.
Fellow photographer Urs Recher had one made with a very long cable that he could plug into the lights or the camera and then he simply moved the trigger further from the sound as an alternative to a delay time.
Finally, if you’re looking for the fastest and minimum delay time then I recommend you plug the trigger directly into your studio flash lights.
You can then activate and open the shutter on your camera, in a darkened room, so that there is no delay from the camera. Then when the sound, laser or object activates the trigger the lights are fired almost instantaneously and the image is recorded without any additional delay from the camera's shutter.
But don’t forget that you don’t have to use a trigger; you can capture great motion shots by judging it by eye. I use eye judgement for all my model jumping and action shots because I prefer the spontaneity and the more random results that this creates, giving me more choice of expressions and moments captured.
To learn more about how to photograph moving objects, make sure to take a look at our extensive range of classes. Many of these detail how to capture the perfect moment, whether you're using flash triggers or shooting by eye. Below is a selection of some of our most popular classes.