Taking the flash off the camera

Learning goal

By taking the flash off the top of the camera and firing it remotely with a trigger, you will be able to choose the direction of the light independently of the lens. You will explain why off-camera flash, by freeing the light and the lens from the same axis, removes flat light and red-eye on its own, and you will tell apart under which conditions wired, optical and radio triggering work and under which they don't. You will position a flash you put on a light stand as the key light, and by changing its angle, height and distance you will decide where the shadow falls and how dark the background stays. You will see how side light changes shine and texture on different skin tones, and fine-tune the flash's position accordingly.

The question

The master of the pottery workshop in your neighborhood lets you shoot their portrait at the wheel in the evening after closing. The workshop is dim; on the shelves are jugs left to dry, and on the workbench muddy tools. In the first frame you shoot with the flash on top of the camera, the master's face is dead flat, the clay stains on their apron have turned into bright white dots, and the shelves behind them are in the dark. The ceiling is high and sooty; there is no surface to bounce off either. Then you take the flash off the camera, put it on a stand, place it to the master's left, a little above, and fire it with a small transmitter on top of the camera. The same flash, the same power. But this time one side of the master's face is lit, the other side in a soft shadow; the wrinkles on their forehead, the texture of the clay on their hands, the curve of the half-made jug on the wheel suddenly stand out.

What changes when the flash leaves the camera? Why does moving the light a few steps to the side make a photo so different?

Context

Throughout this module, to solve the flash's problems, we always accepted that the flash stands on top of the camera: we turned its head to the ceiling, adjusted its power, blended it with ambient light. But what really decides the direction of the light is where it stands relative to the subject, and a flash on top of the camera always stays beside the lens. Bouncing gets past this limit only if there is a suitable surface.

Taking the flash off the camera removes this limit completely. Now the light can stand anywhere a window or the sun could stand, and the photographer can build the direction they would have to wait for in natural light themselves. This lesson tells the tools needed for this and the basic logic of positioning light.

Simple explanation

How is a flash fired remotely?

Off-camera flash is a flash that stands not on top of the camera but in a place separate from it, and is fired remotely. The camera needs to pass the firing command to the flash at the moment the shutter is pressed. A trigger (transmitter) is the device that sends this command from the camera to the flash; it is usually a small transmitter mounted on the camera's flash shoe. A receiver, on the other hand, is the part attached to the top of the flash or built into the flash that catches this command.

There are three basic ways to pass the command. A wired connection is the simplest: the flash is connected to the camera with a cable and the command is passed directly; but the cable's length only lets you take the flash a few steps away. In optical triggering, the camera's own flash or a flash in the shoe sends short light signals, and the distant flash sees these signals and fires; it needs no extra receiver, but the two flashes must see each other, and in strong sunlight the signal can be lost. In radio triggering, on the other hand, the command travels by radio wave; it works even if the flash is behind a wall, inside a box or far away, and today it is the most common and reliable way. Triggers and flashes from different manufacturers can't always talk to each other; before buying a receiver you need to check whether it is compatible with your flash.

Many triggers pass not only the firing command but also TTL information and the power setting. That way you can change the flash's power from your place at the camera, without walking over to the flash.

What does the light's position decide?

The key light is the strongest light, the one that gives the subject shape and decides the exposure. When the flash leaves the camera, the key light's angle, height and distance relative to the subject become your decision. As long as the light stood on the same axis as the lens, the face stayed flat and shadowless, as in the birthday frames in the module's first lesson. The moment you move the light to the side, the shadows fall on the other side of the face and the nose, cheekbones and chin regain their shape. Red-eye also disappears on its own, because the light reflecting back from the eye now returns not to the lens, but to where the flash is.

Changing the angle lets you get all the directions you saw in the lesson on light (Lesson 5.2). If you put the light right in front of the subject, the face flattens again. When you move it about forty-five degrees to the side, one side of the face stays lit and the other in a soft shadow; this is the starting point in many portraits. When you move it to ninety degrees, fully to the side, the face splits in two and a dramatic look appears. When you move the light behind and to the side of the subject, you get an edge light that lights not the face but the edge of the hair and shoulders. There is no right or wrong among these angles; the choice is made according to what feeling the portrait needs to carry.

Height matters too. Because the sun and ceiling lamps most often come from above, the eye is used to shadows falling downward. Placing the key light a little above eye level imitates this natural look: the shadow of the nose comes down toward the lip. If you lower the light below eye level, the shadows fall upward and the face looks eerie, as in horror stories told by flashlight; this is sometimes used on purpose.

Why do distance and the stand matter?

Distance, because light weakens quickly with distance (Lesson 18.2), decides both the light's power and its relationship with the background. When you bring the flash closer to the subject, the subject receives much more light, but the background darkens much faster relative to the subject; the subject stands out in front of a dark background. When you move the flash away, the difference between the subject and the background shrinks and the scene is lit more evenly. Because a source that comes closer looks larger to the subject, the light also softens a little. How much of the background shows, on the other hand, you can manage separately by adjusting the ambient light with the shutter speed, as in the previous lesson.

A light stand is a legged carrier that holds the flash at the desired height and position. A mounting piece attached to its top holds the flash and lets you adjust its angle. Outdoors, wind can easily knock a light stand over; hanging a sandbag or a heavy bag on the stand's legs protects both the flash and the people around. If there is no stand, a friend holding the flash also works; what matters is that the flash is separated from the lens.

Side light behaves differently on different skin tones. On dark skin, side light leaves bright reflections on the forehead, the bridge of the nose and the cheekbones; these reflections move with the angle of the light. Shifting the flash a little to place the shine along the line of the cheekbone gives the face shape; taking the light too much from the front, on the other hand, can turn the reflection into an oily patch in the middle of the forehead. On dark skin the shadow side also deepens quickly; if you want detail in the shadow, putting a reflector on the other side helps. On light skin, on the other hand, side light shows pores, redness and fine lines more clearly; if you want to soften this, you can consider giving the flash a little more from the front or from a larger source. Which texture shows should be the preference of the person and the photo; you check this by enlarging the face in the test frame.

Visual evidence

In the workshop you put the flash on the stand to the master's left, at an angle of about forty-five degrees to their face and a little above their head. In the test frame, on the master's dark skin a thin shine runs along the line of the cheekbone, and the shadow of their nose comes down toward the corner of their lip. The right half of their face is in a soft shadow, but the shadow side is a little too deep; when you lean a white foam board on their right, the detail of the right cheek and eye comes back.

You bring the flash one step closer. The master is brighter, the shelves behind darker; the face stands out in front of a dark background. When you slow the shutter speed a little, the jugs on the shelves reappear with a dim warmth. Finally you move the flash completely behind and to the right of the master and, in one frame, light only the edge of their hair and shoulder: a thin, bright line separates the master from the dark background. With the same flash, only by changing its position, you got three different photos.

Common mistakes

Summary

Off-camera flash is a flash fired remotely with a trigger, freeing the light from the axis of the lens; wired, optical and radio triggering work at different distances and in different conditions, and the most flexible way is radio. When the light is moved to the side, the shadows give the face shape and red-eye disappears; the key light's angle gives different looks like flat, forty-five degrees, full side and edge light, a height a little above eye level looks natural, and distance decides the subject's brightness and how dark the background stays. A light stand holds the flash in place and should be secured; that side light shows shine and texture differently on every skin is checked by enlarging the face in the test frame.

Mini assignment

Do the following tries with a flash, a trigger and a light stand, or with a helper to hold the flash.

1. Take five frames of a person, first with the flash on top of the camera, then taking the flash off the camera and shooting from the front, from forty-five degrees to the side, from full side and from behind; next to each frame write where the shadow falls.
2. At the forty-five-degree angle, shoot two more frames holding the flash above and below eye level, and compare how the face changes.
3. Shoot three frames moving the flash closer to and farther from the subject; look at how much the background darkens relative to the subject.
4. With light at forty-five degrees, shoot two frames with and without a reflector or a white board on the shadow side, and see how the detail in the shadow changes.

Check yourself

• Looking at where the flash is, can you say in advance where the shadow will fall on the face?
• Did you try darkening or brightening the background by changing the distance in your own frames?
• In side light, did you check where the shine and texture gather on the face?

Glossary

Mini quiz

1. Why does taking the flash off the camera and moving it to the side remove red-eye?

• A) Because the flash's power decreases
• B) Because the pupil shrinks
• C) Because the light reflecting back from the eye returns not to the lens but to where the flash is
• D) Because the shutter speed gets shorter

2. In a shoot in strong sunlight where the flash stands behind a box, which is the most reliable way to trigger it?

• A) Radio triggering
• B) Optical triggering
• C) A short cable
• D) The camera's own flash

3. What effect does placing the key light below eye level create on the face?

• A) It flattens the face
• B) It leads to red-eye
• C) It lights the background
• D) It makes the shadows fall upward and the face look eerie

4. There is an oily-looking shine in the middle of a dark-skinned person's forehead. How is it most fitting to adjust the flash's position?

• A) Take the flash right beside the lens, straight in front
• B) Shift the flash a little to the side and place the shine along the line of the cheekbone
• C) Lower the flash below eye level
• D) Double the flash's power

Answers

1. C — Light returns along the same axis; if the flash is away from the lens, the reflection doesn't reach the lens.
2. A — A radio wave reaches behind obstacles and isn't affected by sunlight; an optical signal needs a line of sight.
3. D — The shadows fall not downward as in natural light, but upward.
4. B — Where the shine sits depends on the light's angle; a side angle moves it to a line that gives the face shape.

Summary card

• Taking the flash off the camera frees the light from the lens axis: shape comes back, red-eye disappears.
• The trigger sends, the receiver catches; the most flexible way is radio.
• Angle decides direction, height naturalness, distance the background.
• Secure the light stand against the wind.
• Side light carries shine and texture; fine-tune the flash's position by enlarging the face.

Bridge to the next lesson

When you put the flash on a stand in the workshop and moved it to the side, the face gained shape, but the light was still a bare flash: the shadow of the master's nose was a sharp line, and the shadow of the jug behind them stood on the wall with a crisp edge. You were now choosing the direction of the light, but not its hardness. How does attaching a large box, an umbrella or a round, dish-shaped reflector in front of the flash change this hardness? Softbox, umbrella or beauty dish? The next lesson compares the light modifiers attached in front of the flash, and how light softens as the source grows.