Glance at the summary firstThe summary from the end of the lesson, as a road map before you start reading.
A light modifier's real job is to enlarge the flash's apparent size to the subject; the same modifier softens as it comes closer, hardens as it moves away, and each one swallows part of the light. A softbox softens light and gathers it in one direction and can keep the surroundings dark; an umbrella is cheap and fast but scatters light around the whole room; a beauty dish emphasizes the face's bone structure with a medium-hard, bright, crisp-edged light; a grid narrows the light's spill. The reflection in the eye and the shine on the skin carry the source's shape and size; that is why the choice of modifier is made by looking at how the shine and texture appear on every skin.
Learning goal
You will be able to choose between a softbox, an umbrella and a beauty dish attached in front of an off-camera flash, by looking at how soft, how directional and how spread the light needs to be. You will explain that a light modifier's real job is to enlarge the flash's apparent size to the subject, and so the same modifier gives soft light as it comes closer and hard light as it moves away. You will compare how a softbox gathers light and gives it in one direction, how an umbrella scatters light around the room, and how a beauty dish produces a medium-hard, bright, crisp-edged light, and you will narrow the light's spill with a grid. You will see that the shine on a face is actually a reflection of the source, and check how the modifier's size and shape affect where the shine sits and the roughness of the surface on dark and light skin.
The question
Your cousin is preparing for a conservatory audition and wants a portrait with their violin for the application file. In the small study of their home, you put the flash you took off the camera on a stand. In the first frame you shoot with the bare flash, there is a bright, hard spot on the violin's body, the string's shadow stands on your cousin's cheek as if drawn with a knife, and the bow's shadow stands on the wall like a crisp rod. A friend has lent you three things: a large folding square box, an umbrella, and a round metal dish with a shiny inner surface and a small disc in its middle. You attach all three in front of the flash one after another, and in each frame the light takes on another character.
Softbox, umbrella or beauty dish? Neither the flash nor the power changed; what exactly changes the character of the light so much, and which one is chosen when?
Context
When you took the flash off the camera you gained the freedom to choose the direction of the light; but a bare flash is still a small source and gives hard light. In natural light we solved this problem with a diffusion panel or a sheer curtain stretched in front of a window. When working with flash, the same job is done by tools attached directly in front of the flash.
There are many kinds of these tools, and the name of each is most often used in English in the industry. In this lesson we will compare the three most common ones by what they do to light. None of them is superior to the others; each answers a different need. Knowing what you want a modifier for before buying it saves you from a box waiting in the bag without ever being opened; besides, most of them have cheap equivalents that can be built with things at home.
Simple explanation
How does a modifier soften light?
A light modifier is a tool attached in front of a flash or a lamp that changes the size, direction and spread of the light. What decides the softness of light is how large the source looks to the subject (Lesson 5.3). A flash a few centimeters wide turns into a source a meter wide when a meter-wide box is attached in front of it; the light now comes from every point of that wide surface and the edges of the shadows soften.
That is why, as much as a modifier's real size, its distance from the subject matters. The same box looks enormous seen from half a meter from the face, and like a small square seen from five meters. When the distance doubles, the source looks half the size seen from the subject and the light hardens. Putting a large modifier far away wastes all its benefit; bringing a small modifier very close, on the other hand, can give a surprisingly soft light.
Every modifier also has a price. Fabrics, inner surfaces and diffusing layers reduce the flash's light; that is why when a modifier is attached you may need to raise the flash power.
How do a softbox and an umbrella differ?
A softbox is a box that encloses the flash, with a reflective inner surface and a front covered with diffusing fabric. The flash's light reflects inside the box, scatters as it passes through the front fabric, and reaches the subject as a wide, soft light that is still gathered in one direction. Because the edges of the box limit the light from spilling to the sides, a softbox lets you send soft light where you want it and keep the surroundings in the dark. There are square, rectangular, long and narrow, or octagonal shapes; a long, narrow softbox is used, for example, to light a person's height or the body of a violin from end to end.
An umbrella is a folding modifier that widens the flash's light either by passing it through or by reflecting it back from its inner surface. In a shoot-through umbrella the flash fires from behind the umbrella and the light passes through the translucent fabric; in a reflective umbrella the flash fires into the umbrella and the light returns to the subject from the white or silver inner surface. A silver surface gives a brighter and slightly harder light than white. Umbrellas are cheap, light and quick to set up; but they scatter light over a very wide area. The light goes not only to the subject but also to the walls, the ceiling and the background. This is an advantage when you want to light a group or a room evenly, and a disadvantage when you want to keep the background dark.
A grid is a honeycomb of small cells attached in front of a modifier, and it reduces the light's spill to the sides by holding it at a narrower angle. A grid attached in front of a softbox largely keeps the light's softness while preventing the background and surroundings from being lit.
What kind of light does a beauty dish give?
A beauty dish is a round, shallow metal dish with a shiny inner surface and a small disc in its middle that blocks the flash's direct light. The flash's light first hits this disc, then reflects from the dish's inner surface to the subject. The result is a medium-hard light, brighter and more contrasty than a softbox of the same size, and much softer than a bare flash. The edges of the shadows are distinct but not sharp; a short, clear transition forms between light and shadow on the face. When a diffusing fabric is put over its front, the light softens somewhat more.
A beauty dish is generally used close to the face and a little from above. It makes the face's bone structure, jawline and cheekbones stand out. Because it sits somewhere between the wrapping softness of a softbox and the hardness of a bare flash, it is preferred when a crisp but not harsh look is wanted. Which one is used, on the other hand, is an aesthetic decision; it depends on whether a portrait is wanted to look softer or more sculpted.
A modifier also leaves a trace in the eyes. The eye, like a small domed mirror, reflects the shape of the source in front of it. A square softbox leaves a small square window in the eye, an octagonal box and a beauty dish a round point, an umbrella a domed glint. Many photographers recognize the modifier used by looking at this reflection in the eyes of a portrait.
The shine on the face forms by the same principle: the bright area seen on the skin is the source's reflection on that surface. That is why the modifier's size decides the shine's size. On dark skin, a large softbox spreads a wide, soft glow over the forehead and cheeks; a beauty dish leaves smaller, brighter, crisper-edged shines, which can emphasize the shape of the face but, if its angle isn't set well, can also turn into an oily look. On light skin, the beauty dish's contrast brings pores and wrinkles forward, while a large softbox softens the texture by lengthening the transition between light and shadow. Enlarging the face in the test frame and checking the size and position of the shine makes the choice clear.
Visual evidence
In the study you first put the ninety-centimeter square softbox to your cousin's left, one meter from their face. The string's shadow falling on the cheek turns into a soft, blurry strip; the shine on the violin's body is a wide, soft patch of light. On your cousin's dark skin there is a calm glow spreading from the forehead toward the cheek, and a small square window in each eye. The wall behind stays in the dark.
Then you put the umbrella in the same place. The light is still soft, but this time all the walls of the room have lit up; the bookcase behind your cousin can be made out, and the shadows are a little lighter too. Finally you attach the beauty dish and bring it a little closer to their face. The jawline and cheekbones stand out, and a bright, round reflection appears on the violin's varnished surface. The shine on your cousin's cheek is now smaller and brighter; there is a slightly oily-looking point on their forehead. When you turn the beauty dish a little up and to the side, the shine slides to the line of the cheekbone. You decide together which one to choose for the file, talking about how your cousin wants to appear to the audition panel.
Common mistakes
Common mistakePutting a large softbox far from the subject and expecting soft light.
Seen from the subject the source shrinks and the light hardens. The fix: bring the modifier as close to the subject as the framing allows.
Common mistakeUsing an umbrella in a frame where you want to keep the background dark.
The light scatters around the whole room and the background lights up. The fix: use a softbox, and if needed attach a grid in front of it.
Common mistakeLeaving the flash power the same after a modifier is attached.
The fabric and inner surface swallow part of the light, and the frame is underexposed. The fix: shoot a test frame and set the power or the flash exposure compensation again.
Summary
A light modifier's real job is to enlarge the flash's apparent size to the subject; the same modifier softens as it comes closer, hardens as it moves away, and each one swallows part of the light. A softbox softens light and gathers it in one direction and can keep the surroundings dark; an umbrella is cheap and fast but scatters light around the whole room; a beauty dish emphasizes the face's bone structure with a medium-hard, bright, crisp-edged light; a grid narrows the light's spill. The reflection in the eye and the shine on the skin carry the source's shape and size; that is why the choice of modifier is made by looking at how the shine and texture appear on every skin.
Mini assignment
If you don't have a modifier, you can build equivalents with things from home like a large white cardboard box, a white sheet and a pizza tray.
- Shoot the same person with the bare flash, with a softbox or sheet, with an umbrella, and with a beauty dish or a similar dish, from the same place and the same distance.
- Shoot three frames holding the softbox half a meter, one meter and two meters from the face, and compare the edge of the shadow.
- Across the four frames, note side by side the shape of the reflection in the eyes and the size of the shine on the skin.
- Compare the umbrella and the softbox while wanting to keep the background dark; look at how much the background lights up.
Check yourself
- Can you guess which modifier was used from the reflection in the eyes of a portrait?
- Did you see in your own frames how the same modifier's light changes as the distance changes?
- With each modifier, did you compare the size of the bright area on the skin by enlarging the face?
Glossary
| Term | Short definition |
|---|---|
| Light modifier | A tool attached in front of the source that changes the size, direction and spread of the light. |
| Softbox | A box with a reflective inner surface and a diffusing fabric front that softens light and gathers it in one direction. |
| Umbrella | A folding modifier that widens the flash's light by passing it through or reflecting it from its inner surface. |
| Beauty dish | A round dish with a small disc in its middle and a shiny inner surface that gives medium-hard light. |
| Grid | A cellular grid that holds light at a narrow angle and reduces its spill to the sides. |
Mini quiz
1. How does the light change when you move the same softbox twice as far from the subject?
- A) It gets softer
- B) It hardens, because the source looks smaller to the subject
- C) Its color warms
- D) It doesn't change
2. You want a soft portrait in front of a dark background. Which modifier is most suitable?
- A) A shoot-through umbrella that scatters light around the room
- B) A bare flash
- C) Bouncing off the ceiling
- D) A softbox with a grid attached in front of it
3. What is the basic feature that separates a beauty dish's light from a softbox's?
- A) It scatters over a wider area
- B) It changes the light's color
- C) It gives a medium-hard, bright, crisp-edged light
- D) It raises the flash's power
4. On a dark-skinned person's cheek the shine is small and very bright, and there is an oily-looking point on their forehead. What does the size of this shine depend on?
- A) The size and angle of the source, that is, the modifier
- B) The camera's ISO value
- C) The lens's focal length
- D) The file format
Answers
- B — Softness depends on the source's apparent size to the subject; when the distance doubles, the apparent size halves.
- D — A softbox gathers light in one direction, and a grid narrows the spill even more; the background stays dark.
- C — The disc in the middle and the shiny inner surface give a light more contrasty than a softbox but much softer than a bare flash.
- A — The shine on the skin is the source's reflection; a large source leaves a wide shine, a small source a small, bright one.
Summary card
- A modifier enlarges the source's apparent size; bring it closer, it softens.
- Softbox: soft and directional; with a grid it keeps the background dark.
- Umbrella: fast and cheap, but scatters light around the room.
- Beauty dish: medium-hard, bright, emphasizes bone structure.
- The reflection in the eye and on the skin is the source's trace; check the shine by enlarging the face.
Bridge to the next lesson
When the violin portrait went into the file, your cousin wanted one more thing: they also needed to send the panel a short playing video. The flash was dark except for the moment it fired; it was no use at all for video. Besides, in every frame you could see how the light would fall only on the screen after pressing the shutter. Does a continuously burning LED panel solve both these problems, and if it does, what does it cost you? Flash or LED? The next lesson compares the ease of continuous light, where you shoot what you see, with the power of flash.