Hair Light and Background Light: How to Separate Your Subject

A hair light is a light placed behind and above your subject that adds a bright edge to their hair and shoulders. A background light is a light aimed at the backdrop behind them. Both do the same main job: they separate the subject from the background, so the portrait looks three dimensional instead of flat.

After learning to place a main light, many beginners find their portraits look a little flat, especially against dark backgrounds. Dark hair blends into a dark backdrop, and shoulders seem to melt into the shadows. Adding a hair light or a background light is often the single biggest improvement you can make, and it only takes one extra light.

This guide explains in plain words what hair lights and background lights do, where to place them, how bright to make them, which modifiers suit them, step by step setups with settings, how to avoid flare and spill, and the common mistakes beginners make. There is a 10-minute exercise at the end and answers to common questions.

Why separation matters

Human eyes see depth easily in real life, but a photo is flat. To create a sense of depth, photographers use differences in brightness, color and focus between subject and background. When the subject’s edges are brighter than the background, or the background is brighter behind the subject, the subject seems to step forward. This is called subject separation.

Hair lights and background lights are two of the most direct ways to create it. They are often used in the classic three point lighting setup: a key light, a fill light and a back light.

The hair light

A hair light, sometimes called a back light, sits behind the subject, usually above their head, pointing down toward the top of their head and shoulders. It creates a soft glow or bright rim along the hair and outline of the body.

Where to place it

• Behind and above the subject, on the opposite side from the camera.
• Slightly to one side, often on the same side as the key light, or the opposite side for a crosslit look.
• High enough that it points down at the hair, roughly 45 degrees above.
• Out of the frame, so the light or its stand does not appear in the photo.

A boom arm, which is a horizontal pole on a light stand, helps place the light directly over the subject without the stand showing. A tall stand placed to one side and angled in also works.

Rim light versus hair light

A hair light lights the top of the head and shoulders. A rim light is placed further to the side and behind, outlining the edge of the face and body. They are closely related, and the names are often used loosely. Both add an edge of light that separates the subject.

The background light

A background light is placed behind the subject and aimed at the backdrop, not at the subject. It brightens the background, often in a soft circle or gradient behind the head and shoulders.

Where to place it

• Behind the subject, low on the floor or on a short stand, pointing up at the backdrop. The subject’s body hides the light.
• Or to one side, pointing across the backdrop, which creates a gradient from bright to dark.
• Aimed at the area behind the head and shoulders, where the glow will create the most separation.

A background light can also change the backdrop’s apparent brightness or color. A grey backdrop can look nearly white with a strong background light, or blue with a blue gel.

How bright should they be?

Start with the hair light about the same brightness as the key light, then adjust by eye. Because the light hits the hair at a steep angle, it often looks brighter than its power suggests. Blonde and grey hair reflect a lot of light and need less power. Dark hair absorbs light and needs more. Shiny hair shows the light more than matte hair.

For the background light, start with it about one stop less than the key light for a gentle glow, or about the same for a bright glow. Push it higher for a white background, as described in white background photography.

The goal is a visible edge or glow that you notice when it is turned off, but that does not draw attention to itself when it is on.

Modifiers for hair and background lights

• Grid: a honeycomb that narrows the beam so light hits only the hair or one part of the background. Very useful. See grid lighting modifiers.
• Snoot: a tube that makes a tight circle of light. Great for a small, intense spot behind the head. See snoots.
• Strip softbox: a long, narrow softbox that gives a soft but controlled edge. Popular for hair and rim lights.
• Small softbox: gentler light, but spills more.
• Bare flash: simple and harsh. Use with care, as it spills everywhere.

For an overview, see light modifiers.

Setup 1: adding a hair light to a one light portrait

1. Start with your main light, for example a softbox at 45 degrees to the subject, and a dark grey or black backdrop.
2. Set the camera: ISO 100, 1/160 second, f/5.6 with flash. Expose the face correctly with the main light only.
3. Place a second light with a grid behind the subject, on a boom or tall stand, about 60 to 90 cm (2 to 3 feet) above their head, pointing down at the hair.
4. Turn off the main light and take a test shot with only the hair light. Look at the edge on the hair and shoulders.
5. Adjust power until the edge is bright but not white and blown out. Start at the same power as the key light and go down if too strong.
6. Turn the main light back on and take a full test shot.
7. Check for flare: if the photo looks hazy, the hair light is shining into the lens. Move it further back or add a flag between it and the camera.

Setup 2: a background glow behind the head

1. Use a mid grey backdrop, with the subject 1.5 to 2 meters in front of it.
2. Place a small light on the floor directly behind the subject, hidden by their body, pointing up at the backdrop.
3. Add a grid or snoot so the light forms a soft circle.
4. Take a test shot with only the background light on. Aim for a glow behind the head and shoulders that fades toward the edges.
5. Start at one stop less than the key light. Increase for a brighter glow.
6. Turn on the key light and take the final test shot.

Setup 3: four light classic portrait

1. Key light: softbox at 45 degrees, slightly above eye level.
2. Fill light: umbrella or reflector near the camera, one to two stops below the key. See lighting ratios.
3. Hair light: gridded strip box above and behind, about equal to the key.
4. Background light: gridded light on the floor behind the subject, one stop below the key.

Add lights one at a time, checking each with a test shot before adding the next. That way you always know which light is causing any problem.

Natural light versions

You do not need flash for these effects. Outdoors, place the subject with the sun behind them, low in the sky. The sun becomes a natural hair or rim light. Use a reflector in front to light the face. This is the classic golden hour backlit portrait. See working with backlighting.

Indoors, a window behind and to the side of the subject can act as a hair light while a second window or a reflector lights the face. A lamp placed behind the subject and aimed at the wall can act as a background light.

Worked example: dark hair on a dark background

Imagine you photograph someone with dark brown hair against a charcoal backdrop. With only a key light, the top of their head disappears into the background.

1. Add a hair light with a grid above and slightly behind them, on the opposite side from the key.
2. Set it to the same power as the key. Take a test shot. A faint edge appears, but it is weak because dark hair absorbs light.
3. Increase the hair light by one stop. The edge is now clear and the head separates from the backdrop.
4. Add a small background light behind them at one stop below the key. A soft glow appears behind the shoulders, adding even more depth.
5. Check for flare and spill on the face. Flag the hair light if light is reaching the cheeks.

Adjusting for different subjects

The same hair light setting will not suit everyone. A few common situations need small changes.

• Bald or shaved heads. Skin reflects light strongly, so a hair light creates a bright shiny patch. Lower the power a lot, move the light further to the side to make a gentle rim instead, or use a larger, softer modifier.
• Curly or very full hair. Light catches the edges of curls beautifully. A slightly wider, softer source shows the shape of the hair without making it look frizzy.
• Glasses. Lights behind the subject rarely reflect in glasses, but check the edges of the frames for small bright glints and move the light if needed.
• Groups. One hair light cannot cover a whole row of people evenly. Use two lights, one on each side behind the group, or rely on a background light instead.
• Products. The same idea works for objects. A light behind a glass bottle or a shiny product creates a bright edge that outlines its shape against a dark background. Strip softboxes are especially good for this.

Adding color with a background light

A background light is the easiest way to add color to a portrait without buying new backdrops.

1. Start with a mid grey or white backdrop.
2. Fit a colored gel over the background light. Gels are thin sheets of colored plastic that clip or tape over the light.
3. Keep the subject well forward, at least 2 meters from the backdrop, so the key light does not wash out the color.
4. Take a test shot with only the background light. Stronger colors need more power, because the gel absorbs some light.
5. Add the key light. If the color looks weak, reduce the key light’s spill on the backdrop with a grid, or raise the background light’s power.

Blue and teal backgrounds go well with warm skin tones. Orange and red add warmth and energy. For more ideas, see how to add color to the background of a portrait.

Reading a test shot

When you check a test shot with a hair light, zoom in on the top of the head and shoulders. You are looking for:

• A clear, even edge along the hair, not a single hot spot.
• Detail in the brightest area. If the edge is pure white with no texture, lower the power. The highlight warning on your camera helps here.
• No light on the nose or cheeks. If the hair light reaches the face, raise it or move it further behind.
• No haze over the whole image. A hazy look means flare.

For the background light, look at the backdrop behind the head. The glow should fade smoothly, with no hard circle edge unless you want one. If the edge is too sharp, move the light further from the backdrop or remove the snoot and use a grid instead.

A budget trick: one light, two jobs

If you only own one light, you can still add separation. Place a silver reflector or a small mirror behind and above the subject, angled to catch some of the key light and bounce it back onto their hair. It is weaker than a second light, but often enough for a subtle edge. A white wall behind and to the side of the subject can also bounce enough light to lift the background a little.

Controlling flare and spill

Lights behind the subject point roughly toward the camera, which can cause flare, a haze that lowers contrast. To prevent it:

• Use a grid or snoot to narrow the beam.
• Place a black card or flag between the light and the lens.
• Use a lens hood.
• Move the light further behind or higher.

Also watch for spill, light from the hair light landing on the subject’s nose, cheeks or forehead. It creates bright patches that look odd. Adjust the angle or add a flag.

Common mistakes

• Too bright. A blown out halo looks artificial. Reduce power until the edge is bright but holds detail.
• Light in the frame. Check the edges of the photo for stands or lights.
• Flare. Use grids, flags and a lens hood.
• Spill on the face. Adjust the hair light angle so it lights only hair and shoulders.
• Background light visible. Hide it behind the subject’s body or outside the frame.
• Adding all lights at once. Add and test one at a time.
• Same power for every hair color. Dark hair needs more light, blonde hair less.

Try this: a 10-minute separation test

1. Minute 1: Place a subject, or a mannequin head, in front of a dark backdrop with one key light.
2. Minute 2: Take a photo with only the key light.
3. Minute 3: Add a second light, or a lamp, behind and above the subject, pointing at the top of the head.
4. Minute 4: Take a photo with only that light on.
5. Minute 5: Turn both on and take a photo.
6. Minute 6: Move the second light to the floor behind the subject, aimed at the backdrop.
7. Minute 7: Take a photo with both lights on.
8. Minutes 8 to 9: Compare all four photos. Which separation do you like best?
9. Minute 10: Note the position and power for next time.

Frequently asked questions

What is a hair light in photography?

A light placed behind and above the subject that lights the hair and shoulders, separating them from the background.

What is a background light?

A light aimed at the backdrop behind the subject, used to brighten it, add a glow or change its color.

Do I need both?

No. Either one adds separation. Many portraits use only one, depending on the background and the look you want.

How bright should a hair light be?

Start around the same power as the key light and adjust. Dark hair needs more, blonde or grey hair less.

How do I stop flare from a hair light?

Use a grid or snoot, add a flag between the light and the lens, and use a lens hood.

Can I use the sun as a hair light?

Yes. Place the sun behind the subject when it is low, and use a reflector to light the face.

Want to see how three lights work together? Read the guide to three point lighting.

Curious how to give your backdrop a new look? See photography backdrops.