How to put together a Lighting Kit for Video (Part Three): Light Modifiers

By Sareesh Sudhakaran

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In Part One we looked at ways to quantify light to determine how much intensity we need.

In Part Two we looked at the different types of light, and what they bring to the table. We also covered hard vs soft light.

In this part we’ll look at light modifiers and sources, and how each type of system affects the overall result. Based on this information, we will be able to put together a lighting kit for video.

Kino Flo Bank

When you start reading about lights and the different types of lights, you get the feeling there’s too much to cover. If you are a newcomer, you might be overwhelmed. Do you really need to know all this stuff? Actually, you do. But the good news is, you don’t have to know all of it right now.

Think of these new terms as playing cards spread on a table. You probably remember the first time you saw all these cards, suits, etc., and thought: “What the heck is all this?” This article will have a similar effect, and the simple way to deal with it is just stand back and look at it from afar.

You don’t have to memorize the following terms or commit to anything at this point. You’ll have enough opportunities to familiarize yourself later.

The Case of the Imaginary Wall

If space decides how much light you need, space also decides where you are allowed to place your lights. Look at this:

The Imaginary Wall

There is always a subject, and there is always a light source (even the sun or moon is a source). The imaginary wall is something that limits the relationship between the two.

For interior locations, this is pretty much obvious. The walls of the room or studio you are shooting in limit the placement of your light source. You can’t put it outside, can you? This same analogy applies for the sun as well. It’s always there, but your subject might be indoors, and the imaginary wall limits it (windows) or blocks it entirely (real walls).

When you’re in an exterior location, you still have the imaginary wall. You might have trees, other buildings, roads, etc., blocking the sun. If you aren’t relying on the sun, and have light sources of your own, you are limited by where the generator can park, edges of where you can place the light (riverside, roads, and so on), laws, power sources, cables and so on.

No matter where you’re shooting, you always have an imaginary wall at a certain distance from your subject. This wall limits

  • where you can place your lights, and
  • how many lights you can place within this distance.
  •  

    Bounce vs Diffused Lighting

    Interior lighting is designed for diffused light (soft light). We no longer use raw tungsten bulbs in our homes or offices (or do we?). Take a look around you. You’ll see fluorescent banks in offices and public areas. You’ll see tungsten or fluorescent sources diffused by lamp shades in homes, and you’ll see LEDs, tungstens or fluorescents in shops, malls, etc.

    In regions where sunlight is mild (north light away from the Equator), you have normal glass windows. In regions where sunlight is harsh (Equator) you have windows either tinted or frosted. Obviously, this system isn’t followed half the time, because not all architects agree on how light should be used. At the very least, we have roofs over our heads so the noon sun is rarely in our interior spaces. That’s a start.

    For this reason and more, recreating the effects of soft lighting is extremely important. For situations that are dramatic, or which have to justify the sun as a source, hard lighting is extremely important. You need both kinds of lighting in your kits.

    The two ways in which we can soften light are:

  • Bounced lighting
  • Diffused Lighting
  •  
    Look at the basic difference:

    Bounced vs Diffused Lighting

    Look at image A. Due to the proximity of the imaginary wall, you might not have enough space to put a diffused light between it and your subject. You might have other limitations, like e.g., the light source might be visible in your frame, etc. When we place lights, there’s always a certain amount of ‘tweaking’ involved. This tweaking is done in a physical space – you move lights around, you rotate them, you change the angles or heights, etc.

    In simple terms, an imaginary wall restricts your freedom. Look at image B. When you’re faced with an imaginary wall you can bounce (reflect) light off the wall. This ‘wall’ could be an actual bare wall, or a wall covered in diffusion material, or a foam board, or a reflector, etc. More on these later.

    As a general rule of thumb, when you have more space, you can diffuse light and move it around. When you don’t have space, it is easier to bounce. There is no such thing as ‘one is better than the other’. A good cinematographer must know how to use both, and a good lighting kit will have allowances for both. That’s the only point I’m making.

    An early decision most cinematographers make on any project is to segregate their use of hard or soft lighting, and then (after having seen the actual locations) decide how they are going to tackle the problem of soft lighting.

    A beginner isn’t expected to have the experience to know how to tackle all scenarios. Usually, you learn as you go, and handle problems on a case-by-case basis. The idea of a beginner lighting kit is to have sufficient resources at hand to at least give you a shot at tackling these problems.

    The Light Source

    A diffusion system is one which forms an integral ‘alliance’ with the bulb. Together, they diffuse and shape the light. In essence, the combination behaves like a single source.

    E.g., look at this simple difference:

    Image Source: http://www.iamanangelchaser.com/processes/light_bulb_recycling/light_bulb_recycling.html

    You could apply similar concepts to get a softbox:

    Softbox

    A softbox is nothing but a diffusion element in front of a lamp/bulb to soften the source. You could call the ‘combo’ a single lighting source. You don’t have to get too technical with your definitions here. No one’s going to ask you these things on the field. I break it down this way for easy understanding. Learn, understand, and then forget!

    Bounced light can also be called a single source. If you step back and look at diffused or bounced lighting sources, ultimately they all achieve the same purpose – which is to soften the light given the constraints of the space created by the imaginary wall.

    Diffusion systems

    I’m not going into the details here, but for quick reference, here are the most popular diffusion systems:

  • Diffused light sources (e.g., fluorescent lights are already diffused inherently)
  • Light banks (many light bulbs put next to each other – therefore a ‘bank’ – act as a diffused source. Fluorescent and LED lights are used as banks more often than not)
  • Fresnel lens (a lens and bulb arrangement that allows you to spot (focus the light beam) or flood (spread the light beam) for aesthetic effect)
  • Softbox or Chimera (Depending on how big you want your diffused source, softboxes can be created in various sizes and shapes)
  • Reflectors (material that has a special surface to reflect light. The most popular types are silver, gold and white)
  • Muslin or Cotton or Calico (cloth that reflects or diffuses light, comes in bleached or unbleached versions)
  • China lanterns or balls (These are similar to home lampshades made of paper or cloth, and come in various sizes and shapes. The most popular is the globe-shaped material, hence the name China Balls)
  • Umbrellas (These are umbrellas that reflect or diffuse light, and are available in silver, gold or white)
  • Foamboard (boards made of foam, usually white. These are the cheapest and most handy reflectors available)
  •  
    Hard lights are usually called Open-faced, simply because there’s nothing between the light source (bulb) and the subject. Open faced systems are used for hard lighting and to bounce light off diffused surfaces.

    We have many cards on the table already. There’s more.

    Light Modifiers

    Once light has left the source, you might still want to modify it for many reasons. Some of the prime reasons are:

  • Blocking light from hitting a space you don’t want lit
  • Further diffusing it
  • Changing the color temperature of the light
  • Redirecting it
  •  
    Sometimes the modifiers are on the light source itself, so the distinction is usually a gray area. Who cares?

    Here are some popular light modifiers:

  • Barn doors (These are flaps placed on the light source to block it from hitting places you don’t want shone)
  • Egg crates (These are egg-crate or grid-like patterns placed in front of the source to diffuse or direct the light. They are very handy in a tight spot)
  • Nets (These are nets either screwed on to the light fixture or placed separately to diffuse light)
  • Filters or Shapers (ND filters are one good example of filters used to cut the intensity of light. There are an infinite number of doohickeys available to diffuse, shape or redirect light. Snoots are one good example, cut-outs are another)
  • Gels change the color temperature to match existing sources of daylight. The most common are CTO (Color Temperature Orange – changes 5600K to 3200K), CTB (Color Temperature Blue – changes 3200K to 5600K) and Minus Green (Removes green casts due to fluorescent lighting). All of these gels come in various ‘strengths’ so you can precisely set your temperature.
  • Flags – these are black boards of various sizes and shapes that are placed in different areas to cut light selectively.
  • Mirrors – these are mirrors of all kinds that reflect light, usually used in tandem with direct sunlight.
  •  
    When you have the time, Google these terms and take them in slowly. Some are extremely handy, while others are used only for specific scenarios. Once you’ve played cards long enough, they become second nature. Take your time.

    In Part Four we’ll finally pick and choose, and put together our first lighting kit.

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    April 3, 2013

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