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An Introduction to Indoor and Studio Flash Photography

This post is part of a series called Studio Portrait Lighting.
Rules for Perfect Lighting: Understanding The Inverse-Square Law



In photography there are two types of light; hard or harsh light, and soft or diffused light. Hard light casts deep sharp shadows with well-defined edges, such as the case in high mid-day sun. Soft light casts softer shadows with edges less defined, such as the case on an overcast day. That’s because the light is bounced and diffused in different directions and is spilling into the shadows, so the size of the light becomes much larger.

The effective size of the light depends on two factors:

  • The actual physical size of the light.
  • The light's position in relation to the subject.

The closer the light is to the subject, the larger the effective size and the softer it is. The further the light is from the subject, the smaller the effective size and the harder it is. So you can easily change the quality of light by changing the effective size.

This brings up another issue - contrast. Contrast is the difference between the light and shadow areas of your scene. The greater the difference, the more contrast the scene is said to have. The smaller the difference, the less contrast the scene is said to have.

Lighting Equipment

Most lighting equipment falls into one of three different classes: Grips, Modifiers, and Light Sources.




The Standard 3-Light Setup

A 3-light setup consists of: a key light, a fill light, and a separation light.

Key light is the main light that has the most significance in your scene. It creates the defining highlight and shadow areas of your shot, and is the light that all your others are based upon.

If the key light was the only source of illumination, the subject would have a well-defined side, with the back and other side appearing fairly dark. This could result in dramatic high-contrast effect if done creatively, as shown in the images below.

indoor flash photography
Photo by Dustin Diaz
indoor flash photography
Photo by Dustin Diaz

The fill light is a secondary source of light that is used in conjunction with your key light to open up the shadows at the other side of your subject, and cut down on scene contrast.

Separation light - or hair light - is the third source of light, and is used if you have a dark subject against a dark background. So the separation light would come in handy for separating your subject from the background, providing a good outline from behind and pulling it out from the background.

So ideally you would have a main light source to one side of your model set up on a stand, with a soft box or an umbrella on your strobe for softer, defused light. To the other side of your model you would have either a fill light or a bounce card, to fill in the shadows on that side of the model (also set up on a stand). The fill light or reflector would be set a little bit lower than your key light, and it could also be placed further away from your model than the key light.

And finally you would have a separation light placed behind your model from above to separate them from the background. You could also place a backdrop of your choice behind your model if the natural background is not very flattering (or too cluttered).

Note that if you remove the separation light from the diagram above, you end up with a basic two-light setup. This is useful when your subject doesn’t need separation from the background (due to a different backdrop or background tone), or to purposefully blend the subject into the background for creative effect.

indoor flash photography
Photo by Dustin Diaz
indoor flash photography
Photo by Dustin Diaz
indoor flash photography
Photo by John D.

Lighting Ratios

The lighting ratio is the comparison of the key light and the fill light. For a soft even lighting, you would use a lighting ratio of 1:1. A 1:1 lighting ration means that the brightness from the key light would be the same as the brightness from the fill light. So if the key light metered at f/8, then the fill light would need to similarly meter at f/8.

A 2:1 lighting ratio means that the key light is twice as bright as the fill light. This is a difference of 1 full stop. So if the key light metered at f/8, then the fill light would need to meter at f/5.6

A 4:1 lighting ratios means that the key light is four times brighter than the fill light. This is a difference of 2 stops. So if the key light metered at f/8, the fill light would need to meter at f/4. And so on…

So if you want to have flat light, you would use a 1:1 ratio. If you want to have a cool effect, you would use a 2:1 ratio. If you want to have a strong dramatic effect, you would use an 8:1 ratio for great contrast in the scene. The higher the ratio, the higher the contrast.

It's also important to keep in mind that the positioning of your lights highly impacts the contrast of your scene as well. To get the highest effect from lighting ratios, make sure you keep your lights at an angle of 45 degrees or more from your camera. The greater the angle, the greater the contrast.

Very Basic Lighting Setups

  • Basic Portrait Light: This setup uses two softboxes. A small one below and a large one above it, at the same angle. The lighting ratio is 2:1

    The large softbox acts as the key light, and it also could illuminate the background if it was dark. The small softbox acts as the fill light. The photographer would shoot right through the gap in the vertical axis between the softboxes, while standing behind them.

  • Basic Fashion light: This setup uses a 4x6 softbox with a grid, and a large foam cord bookend as a reflector. You can move the foam cord reflector closer to the model for more fill, or further away from the model for less fill. This setup uses a 4:1, or an 8:1 lighting ratio.

  • Basic Beauty light: This setup is exactly the same as the fashion light setup above, only substituting the large softbox with a beauty dish. This gives a little bit harder light, with greater contrast. The lighting ratio of this setup is 4:1.

  • Lens Flare Effect: This setup uses a ring flash above, and to the right of the model, and a bare head behind the model also to the right for some intentional lens flare. The lighting ratio is 4:1, with the bare light head metering twice as bright as the key light.

Side Bounce

If you're low on budget, don't have much time for a big setup, or don’t have your gear readily available, you can pose your model a couple feet away from a wall, place your light source facing the wall (as shown below), and have the light bounce off the wall from the side to complement and more naturally illuminate your model.

Using this technique, you can experiment with how far your light would be by moving it closer (for a smaller softbox effect) or further away (for a larger softbox effect) from the wall.

You can also attach a flag to your light source to keep light from spilling onto your model, or you can go without a flag for a nice catchlight effect.

indoor flash photography

If you find yourself in a place with no bright walls, you could use anything that can act as a bounce surface: a reflector, white cardboard, a light table cloth, or even someone wearing a white shirt. All those can be used as a bounce surface. You just face your light toward whatever it is you find available to act as your bounce surface, and place your model to the side of that surface!

What's a Flag?

A flag is anything that is used to block light in a controlled way, preventing it from spilling onto your model. It could also be used to prevent light from flaring into the camera lens.

Surround Bounce

You can use this technique by setting up your flash unit in a way that would illuminate a large bounce area of a medium-sized room, by taking advantage of walls and ceiling to scatter and diffuse light as you find appropriate.

Using surround bounce gives your photos a natural-like light that is typically available with no artificial lighting involvement.

Floor Shots

Floor shots are just like any other wall bounce shots, only flipping everything 90 degrees towards the ceiling as it acts as your softbox. Your model would be lying on the floor, with your light source pointing towards the ceiling and bouncing back to illuminate your subject and the surrounding environment in general.

You could also substitute the ceiling with an umbrella, with the flash facing away from your subject. The light would bounce off the umbrella and onto your subject, easily illuminating them while you create your masterpiece.

Here are a couple of examples:

indoor flash photography

Making Use of Ambient Light

Ambient light can also be used for lighting in an indoor photo shoot, either with or without a flash. It could be used as a rim light from behind, pulling your subject away from the background while you light up their face with an on camera flash.

Ambient light could also be used alone to take care of lighting. You could make use of any light bulbs, table lamps and so on. For ambient-only lighting in a fairly dark environment you could place two table lamps (taking the shades off) opposite to each other with your model in between.

You would place one of them closer to the subject than the other, to act as a main light while the opposite light source acts as a fill light. A plus of this technique is that you can take your readings in real-time as the light falls on your subject.

indoor flash photography
indoor flash photography
Photo by Bob
indoor flash photography
Photo by Daniel Greene

Making Use of Window Light

Windows are a great light source for indoor photography, especially if they're large or emitting great amounts of light.

You could place your subject against a window and shoot them from the front (with or without an on camera flash). Of course if you do use a flash, it would be your key light and the window light would be your softbox. You could also expose for your subject without regard for the window light, to get a high key result.

Alternatively, you could use window light as key light by turning your model to the side, having half their face lit by the window while the other side fairly lit by available room light for dramatic creative results. Or you could use it as fill light by placing your subject in the same manner, and having a main light source positioned to the other side to act as your key light.

indoor flash photography
indoor flash photography
Photo by Gabor Szantai
indoor flash photography
Photo by Jay Ryness


Indoor and studio flash photography is a huge subject, but today I tried to provide you with a sufficient introduction to light, it's various qualities, as well as how we can bend and adjust those qualities to suit our own taste and needs for great professional results.

We have also been over a few basic lighting setups, as well as how to make use of the surrounding environment to our advantage, so that you guys can embark upon this creative journey and take the best photos you can!

If you have anything to add to the principles and ideas above, I'd love to read your comment!

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