The word alone has the potential to cause dread, even among experienced photographers, bringing to mind images of overexposed faces and red eyes. Because of this, many photographers avoid flash altogether, keeping a safe distance at all times. I think that’s too bad.
It’s a missed opportunity. Sure, flash may not always be applicable to your situation – but it’s very helpful to have another tool in your bag of tricks if and when it is needed.
Off-camera flash gives you an incredible amount of control. Yes, understanding natural light is an important part of being a photographer – but working with off-camera flash lets you create your own lighting conditions. You can even mimic the elusive golden hour.
This guide will explain off-camera flash in its simplest components, giving you the knowledge to begin to experiment, and to explore how it could help your photography.
What you need to start
When I talk about off-camera flash, you might be picturing something like this:
If that’s the case, I don’t blame you for being a bit nervous. In reality, all you need to get started with off-camera flash photography is:
- A camera
- An independent flash unit
- A way to make them fire simultaneously
- Something to hold your flash, like a light stand or a friend
Once you take your flash unit off of the camera, it won’t know that it is supposed to fire when you hit the shutter button. Fortunately, there are several ways that you can sync your flash.
Built-In Flash Control: Some cameras have a built-in setting that uses the pop-up flash to tell your off-camera flash to fire. Most flash units have a sensor on the front that recognizes the sudden burst of light (optical sensor), and fires accordingly.
Flash Sync Cord: This is a cord that runs from your camera to the flash. Think of it like an extension cord. These are useful and reliable, but it also limits how far away the flash can be from your camera.
Wireless Radio Transmitters: The preferred option, radio transmitters can sync your flash to your shutter even if they are at a significant distance away.
Editor’s note: for more great tips read, A Beginner’s Guide to Working With Flash Off-Camera
The basics – controlling your off-camera flash
When you use a flash on-camera, it can determine the correct power settings and fire accordingly (TTL). Once you take the flash off the camera, however, you’re going to need to tell both the camera and the flash what to do manually.
If that sounds scary, just take a deep breath – we’ll get through this together.
Fortunately, controlling flashes is quite simple. In manual mode (on the flash), you choose the amount of power at which the flash fires. This is expressed as a fraction: 1/1 means the flash is firing at full power, ¼ means the flash is firing at a quarter of its total power, and so on. Easy, right?
Alright, so now we know how to control the flash. What about the settings on your camera?
This is the cool part. You can control the effects of the flash using your ISO and aperture. Adjusting these two settings controls how sensitive your camera sensor is, and how much light it can collect.
So here are the four ways to make the flash in your image stronger (more flash):
- Turn up the flash power
- Move the flash closer to your subject
- Turn up the ISO
- Make the aperture wider (smaller f-stop number)
Piece of cake! Is your flash in your picture too strong? Well, simply do the opposite of one of the criteria mentioned above (turn the flash down, move it away from the subject, turn the ISO down, use a smaller aperture).
You’ll notice that I haven’t mentioned shutter speed yet. That’s because your shutter speed doesn’t affect flash at all.
Well, almost not at all. Every camera has a flash sync-speed. This is because if the shutter speed goes too fast, it won’t sync perfectly with the flash (the shutter will open and close before the flash goes off). As a result, part of your picture won’t see the effects of the flash – resulting in a black bar across part of the shot. For most consumer cameras, your maximum flash sync speed will be around 1/200 or 1/250. Keep your shutter speed under that (slower like 1/125th or 1/60th) and you’ll be fine.
Two exposures: Ambient and flash
This is the key to understanding off-camera flash photography.
Think of every picture taken with flash as being two exposures, overlapped on top of each other. The way you decide to balance the ambient lighting and the flash, sets the tone for the image. Let’s take it one layer at a time, and you’ll see how easy it can be to build an image using off-camera flash.
THE FIRST LAYER: AMBIENT LIGHTING
Ambient light is that which is already available in the area from the sun, window light, street lights, etc. At certain times of the day, your ambient light is going to be quite nice, like at Golden Hour. Other times, you may not be so lucky.
Sunsets, for example, are especially tricky. This is because in order to bring out the colour and texture of a sunset, you need to keep the exposure dark – and as a result, your subject will be completely silhouetted.
Here’s the first step for taking your off-camera flash picture – ignore your flash altogether. Turn it off.
Find the normal, correct exposure for the existing (ambient or available) light, and then adjust your settings to intentionally make your image too dark. The darker your ambient exposure, the more dramatic the light from your flash will be.
Here is my exposure for the ambient light (above). We’re off to a good start! For this shot, I want to keep the dark, dramatic sky in the background, and I will rely on my flash to light up the tennis player.
THE SECOND LAYER: FLASH
Alright, now turn on your flash. By using flash to light my subject, I can get the best of both worlds – my sky remains dark and dramatic while my subject is well-lit.
It will probably take a few shots to get your lighting right. That’s perfectly normal! Use the tips mentioned in the previous section to add more or less power to your flash.
When we add the flashes, we get to keep the dramatic background, with the benefit of crisp lighting on our subject. This shot simply isn’t possible without flash.
You can use what you know about ambient and flash lighting to set the tone of the image.
If you keep your ambient light levels high, the flash will add just a kiss of light. If you start with a very dark ambient image (like the one above), your flash will sculpt and define the image much more strongly.
Here’s the behind-the-scenes of our setup. Since the light is hitting the subject from an angle, it is dramatic and shows shape much more effectively than if the flash had been on the camera. One flash is to camera right, bouncing into an umbrella to soften it, the other is to camera left (and behind the subject) to add an accent light.
Putting it into Practice
Here’s another example, this time using flash to give a simple kick, to a liven up a portrait.
The first step was to push the “correct” exposure down, making the overall image darker, so that we could use flash to highlight the subject.
In the image above (left), the flash is coming from just left of the camera. It brightens the subject up (compared to the background), and makes the image seem more three dimensional. The background also pops more than it did with the “correct” exposure.
If we want to, we can play around with the effects of a second flash (above right), maybe letting it aim directly toward the camera to create some lens flare?
Shaping and modifying your light
Well done! You’ve made it through the basics of off-camera flash photography. Next, you can push your newfound skill to a whole new level by learning how to modify the light.
If you’re familiar with how the light on a cloudy day is softer than the light on a sunny day, then you already know nearly everything you need to know about flash modifiers.
The basic rule is this: the larger the light source, the softer the light.
A flash unit is a small light source that creates harsh shadows. That isn’t always so flattering.
The purpose of umbrellas, soft boxes, and other light modifiers, is to make the source of light larger. This softens the light, which is especially useful for portraits.
Learning how to modify light lets you build a style that matches your image.
Looking for a gritty photo? Shoot with a bare flash (no modifiers) and get sharp shadows. Looking for softer, more flattering light? Use a softbox.
Practice, practice, practice
Once you’ve got a feel for how to use your flash off-camera, you’ll have a whole new world of photography to explore. Try it. The worst thing that can possibly happen is that you’ll learn something.
Using digital equipment gives you the ability to try things without any financial repercussions. Learning flash photography through trial and error was probably pretty expensive back in the days of film; today you can fire as many shots as you need in order to learn, without breaking the bank.
Nobody ever got off-camera flash right on their first try – experiment and stick with it, and you’ll add a valuable new tool to your bag of tricks.
More articles for you to read on dPS about off-camera flash:
- How to Create Compelling Wide-Angle Portraits Using One Off-Camera Flash
- 9 Steps to Get Over Your Fear of Off-Camera Flash
- Supporting Your Off-Camera Flash – Tripods, Monopods or Light Stands?
- Beginners Guide to Using TTL Off-Camera Flash
- How to Get Started with Off-Camera Flash Photography – Start With One!
- Getting Started with Off-Camera Flash
- How to Balance Off-Camera Flash and Ambient Light on Location
- A Beginner’s Guide to Working With Flash Off-Camera