The Basics Of Film Lighting
Crews on film sets around the world have a shorthand to communicate everything from tools to style, to execution, to the quality of light. Let’s break down a few common terms you’ll hear on set.
Three Point Lighting
Key light, fill light, and hair light/backlight are the three types of lighting in film. This three-point lighting configuration is the basic cinema lighting setup used in most film shoots. Of the three – the key light is the most important lighting in film because it is the primary source of light in a scene.
Lighting Ratio
A comparison between the output of the key light and the output of a fill light. A higher ratio will lead to an image with more contrast. A lower ratio leads to an image with less contrast.
Low Key Lighting
Produces shadows for a more dramatic look. Often the key light may be significantly brighter than the fill light being used in a scene. This is a common style in dramas and horror films.
High Key Lighting
A lighting concept resulting in fewer shadows and a lighting ratio between key and fill closer to 1:1 (see next entry). Commonly used in comedic films or three-camera sitcom projects.
Fill Light
A source that is placed on the opposite side of the key light to “fill” in shadows.
Backlight/Hair Light
A backlight is used to separate the subject in the shot from the background. A hair light, as its name implies, accents the subject’s hair, which can also help separate the subject from the background.
Inverse Square Law
Light intensity decreases as the square of distance. Said another way, a subject passing in front of a lighting fixture a few feet from the source will clear the light beam in a shorter amount of time than if they walk through the beam at a point further away from the source. This is an important concept to consider when actor blocking contains movement. The image of an actor moving directly towards a lighting fixture will increase in intensity as they approach the light source, and that increase will need to be accounted for by potentially using in-camera exposure changes when placing a light on set.
The inverse square law also should be kept in mind when an actor passes through a beam of light on a parallel trajectory from the source. They might need to be lit for their line of dialogue and not lit for a dramatic exit. To allow for that moment, knowing where to place the lighting instrument is crucial.
Hard and Soft Light
Soft light, common in mediums like fashion films, is a wrapping and flattering light source. Hard light is clearly directional and casts harsher shadows onto the subject. Recognizing the quality of light hitting your subject can allow you to make creative choices to soften a hard light or swap a soft light for a hard light. It’s easy to make a hard light soft using different modifiers, but it is difficult to make a soft light hard.
Butterfly Light
A soft or hard key light placed directly above a subject and angled down for a dramatic and sculpted effect on closeups. Not to be confused with a butterfly frame upon which diffusion can be placed to control overhead light.
Ambient Light
Any form of light not added to a scene by a cinematographer or gaffer. Ambient light may be natural light coming in through a window. It could also refer to the light naturally present on location. For example, a city street.
Eye Light or Catch Light (A.K.A. “Obies”)
A light source that casts a small ping of light in the eye of a subject. Usually created by mounting a small light close to the camera such as a Rosco DMG DASH Light with its DOT Round Diffuser accessory.
A Rosco DMG DASH with a DOT Round Diffuser provides eye light for a scene.
Book Light
Using a book light is a common way to soften a hard light source created by bouncing light against a reflective surface and then softening that light again by using diffusion as it bounces back on the subject.
Practical Light
A light that is visible in the scene being filmed (examples: a lamp, a candle, or a television monitor). Practical lights may be provided by the art department. In the case of lamps, it’s not unusual for a gaffer to swap a consumer bulb for a higher quality bulb.
Motivated Lighting
A lighting source that, to the audience, reads as having come from a realistic source within a scene. For example, a lighting fixture balanced to daylight and hidden just outside the frame over a window might read to an audience as the sun cascading through a window. A fixture balanced to 3200K and bouncing soft light mounted over a practical bed lamp may read to the audience as light emitting only from a bed lamp.
Sourcey
This adjective refers to the direction or source of a light fixture which is interpreted in a certain way by the audience. A sourcey light might refer to a hard fresnel light casting shadows through a window. That light would be considered “sourcey” as the viewer of the film might assume this artificial light fixture is the sun. If a light fixture is too sourcey, it might read as false if the audience is unclear what is emitting the light.
CRI or Color Rendition Index
A measurement of a light source's ability to render an object’s color accurately. Often compared to natural lighting sources. Most modern lighting instruments exhibit a CRI rating of over 90 out of a possible 100. CRI is measured using a device called a spectrometer. We’ll discuss CRI later in the section on evaluating lights.
Color Temperature
The primary unit of heat measurement in the international system of units. In film lighting, we use Kelvin to express CCT or correlated color temperature. CCT gauges how warm or cool a light source is. A candle, for example, has a color temperature of 2700K, while daylight, depending on the time of day, typically has a color temperature of 5600K.
Output
In this context, output is how bright a lighting fixture is. Output is expressed in lumens, foot candles, or lux (each a unit of measuring light).
Light Meter
A tool used to measure proper exposure. Most light meters are reflective or incident-based with an incident meter measuring all light on a subject and a reflective meter measuring light bouncing back from a subject.
Dimmers
Most modern LED fixtures can dim their output using built-in dimmers, but dimmers are sometimes separate devices connected between a fixture power supply and the power source such as a wall socket or other type of generator or external battery. It’s important to pay attention to wattage requirements. Also, be aware some fixtures are not designed to be dimmed.
DMX
An acronym that refers to a standardized digital communication method for controlling lighting fixtures. DMX control can be wired or wireless.
Negative Fill
A black material that serves to absorb or reduce the amount of light being reflected back onto a subject. Very useful in situations where bright natural ambient lighting is present like daytime sunny exteriors. Negative fill can be created with fabric flags & floppies, Blackwrap, or Rosco E276 Blackout.
Golden Hour
This is typically the best time to shoot, either right after sunrise or just before sunset. When the sun is near the horizon, it is shining through more particulates in the air, which creates a soft and warm-toned light that is flattering on most skin tones.
Noon
This is considered by most filmmakers to be the absolute worst time of day to shoot exterior scenes. If there’s no other option, modifiers like bounces, negative fill, and overhead diffusion must be employed to give the sunlight some directionality.
Projections & Gobos
Often used to create everything from simple shadows to complex moving textured light that moves across actors and set pieces. Simple projections using gobos inside ellipsoidal fixtures (like the ETC Source 4) are an excellent way to add simple shadows or texture the light in a scene. A perfect example of this using a venetian blind gobo to create the recognizable noir lighting effect. Using moving lights like the Rosco X-Effects LED Projector can add motion into your projections. This film lighting technique is excellent for creating spectacular lighting effects in a scene.
Five examples of how gobo projections can create color and texture in film lighting setups.
Multiple Shadows
Viewers might recognize a single set of shadows all moving in the same direction as being cast by the sun or a streetlight. Multiple shadows often read as false or as a mistake, and great care should be taken when placing instruments in a way that casts multiple shadows throughout a scene.
Rear Projection & LED Walls
Whether it's a video projector projecting onto an RP screen, or digital projections being created on an LED wall inside an LED volume - the light emanated from these sources must be accounted for when shooting virtual production. While it is often beneficial to have their practical light adding color and reflections on the set, their output is rarely enough to completely illuminate a scene. You will need additional lighting tools for shooting with LED walls and RP screens that can supplement the glow from these indirect light sources.
Directions: Lamp Left & Right, Camera Left & Right, Stand Up & Stand Down
“Lamp left & right” is a method for communicating direction instructions to a crew member moving a lighting fixture. Simply put, “lamp left” or “lamp right” is left or right from the perspective of the back of the lighting fixture. “Camera left” or “camera right” communicates direction from the perspective of the camera. Another popular command is “stand up” or “stand down”, which means lower or raise the stand the fixture is mounted on.
Gaffer, Best Boy, Key Grip
The gaffer is the crew member most responsible for executing the lighting plan on a production. The gaffer often works hand in hand with a cinematographer and a variety of other crew members, including a best boy (called “sparks” in the UK or even “juicers”). The best boy is second to the gaffer and is responsible for the electrical operation of on-set fixtures. A key grip is responsible for safely mounting fixtures to film equipment or set/location architecture.
Atmosphere
Beams of light are invisible to the eye (and to the camera) unless there is some sort of particulate in the air. Adding some sort of "atmosphere" into the scene - usually by using theatrical haze of fog - enables filmmakers to add color and texture into their film lighting setup. Various types of atmosphere can lower lighting contrast and can illustrate mood or dramatic moments. Theatrical haze is a long-lasting, semi-translucent effect that is perfect for catching light beams. Fog or smoke is often more opaque initially, but will eventually dissipate into a haze effect. While atmosphere is often created on set using theatrical haze and fog, smoke, morning mist or naturally occurring environmental dust can also create similar atmospheric effects in a scene.
Four examples of how atmosphere from a Rosco V-Hazer enhanced the film lighting in a scene.
Using a variety of lighting fixtures is common when lighting a film. Some fixtures come from the theater world; others have been around for decades. Power requirement, size, mobility, price, and output vary depending on the fixture. To the touch, some fixtures feel cooler, others hotter. Some fixtures even emit low levels of UV radiation. Each fixture creates a certain quality of light.
Let’s explore the most common lighting fixtures and see how each plays a part.
LED
LED stands for light-emitting diode. A current travels through a small electrical chip and that chip emits light. LED lights are directional and tend to draw less power, create less heat, and have a relatively long lifespan. Common LED colors are red, green, and blue and are often expressed as RGB. LED technology is now the dominant lighting in film production. Currently, the output of LED lighting is bested at the high end by HMI fixtures, but that output gap has been closing as LED technology improved. LED lights can be modified within the fixture or the lamp head to be soft or hard. Further modification is also possible in a variety of ways to create different lighting characteristics.
A Rosco DMG MAXI LED soft light.
LED Tape
A strand or multiple strands of LED diodes arranged in any configuration and in any length. Mostly commonly used as environmental lighting or built into existing art elements. Like most LED instruments, the LED tape can be made of color diodes or single Kelvin temperature diodes.
HMI
Hydrargyrum Medium-Arc Iodide is a type of lighting fixture characterized by an impressive light output and large power draw. Developed in the late 1960s, the HMI fixture is still commonly used on film sets where daylight balanced high-output lighting fixtures are needed. HMI fixtures emit light by passing an electrical current between two electrodes within a bulb, thus exciting mercury vapor and metal halides in a pressurized environment. As of 2022, LED technology doesn’t produce the same output as HMI lights. HMI fixtures tend to create a hard and directional light source.
Fluorescent
An electrical current passes through a mercury vapor, which energizes a phosphor coating on a bulb or tube, causing it to glow. Until recently, fluorescent was a very popular type of lighting used to create a soft and flattering light source. However, in many of the current major film markets, LED lighting has replaced fluorescent.
Tungsten
A warm light source that uses tungsten-halogen bulbs to create a light that hovers around 3200K. Tungsten fixtures tend to be hot and heat-resistant gloves are strongly recommended when handling them. These fixtures have a very appealing price-to-lumen ratio, but draw lots of power in exchange for that level of output.
Fresnel
A common type of light characterized by a soft-edged beam of light, the Fresnel lens was originally developed by a French physicist for lighthouses. That lens was then integrated into film lights. It can be used as a floodlight or as a spotlight and certain brands allow for a variable Fresnel beam that can move between spot and flood, allowing for narrowing or widening beams of light.
The DMG LION - a 13" LED fresnel.
Ellipsoidal/LEKO
A fixture that uses an ellipsoidal-shaped reflector to collect and direct the light through a lens, which allows the light to be focused on a surface. These lights often feature shutters that allow for sharp cuts to the beam. The focusable optics also enable the fixtures to accept gobos – metal or glass discs that can cast shadows, texture the light beam, or project photo-quality imagery.
Space Light
An overhead light that features a cylindrical diffusion shroud for soft light output. These fixtures are usually used in large groups and are intended to light large areas.
Lantern or China Ball
These modifiers are usually mounted overhead. They act to spread and soften a light source over a medium-sized area. They’re very useful for creating a flattering top light in scenes where ground mounted lighting fixtures are difficult to hide from the camera.
Lighting modifiers are pieces of equipment that can alter or improve a lighting source. Modifiers are not only used for artificial lighting. They can also be used to bounce, soften, or flag (i.e. block) sources like the sun.
Barn Doors
This modifier attaches to the front of an instrument and is usually matte black metal to prevent heat damage and unwanted reflection. Barn doors can direct and shape a beam of light.
A Rosco DMG MINI LED soft light with Barn Doors attached.
Soft Box
A heat-resistant “box” that affixes to a fixture to soften the light emitted using diffusive fabrics. A soft box will soften the beam more or less depending on the type of diffusion materials used.
Grid, Egg Crates, or LCDs
Modifiers that are mounted directly to the front of a light fixture or a grip frame to narrow the beam of light and prevent light spilling into the shot.
Gels
Most often made from thin heat-resistant plastics, a gel can color a beam or be used for color correction. It's possible to create an overall color aesthetic with gels. They are denoted by name and sometimes a number designation from brands like Rosco. Gels were originally made from gelatin until the late 70s, and the “gels” nickname has stuck to this day.
Rosco Filter Kits are an excellent way to introduce gels into your film lighting setup.
Neutral Density (aka ND) Gels
Similar in concept to neutral density camera filters, these gel filters are used to dim down the light of windows, so they aren’t over-exposed and aren’t blown out in the shot. These grey gels come in a variety of different densities that lower the amount of light from ½ stop (very light) to 4 stops (very dark).
Diffusion
Heat-resistant materials that are placed between the light source and the subject to scatter the beam to change the look, feel, and character of a lighting source. They soften the light beam, usually at the cost of intensity. Diffusion materials include plastic gels that can be cut and affixed to the barn doors of a light or onto a grip frame, as well as fabric materials that can be sewn together, or viny materials that can be welded together, to form large diffusion panels.
Butterflies and Overheads
Butterflies are diffusion panels that are mounted vertically to standard grip frames. Typical frame sizes are 6’ x 6’, 8’ x 8’, and 12'x12'. Overheads are much larger panels of diffusion that have been sewn together to cover a large area. Some overheads are big enough to cover the entire ceiling of a sound stage.
A 6’x6’ diffusion Butterfly mounted to a grip frame and a pair of C-Stands.
Flags, Floppies and Frames
Flags are made out of various fabrics and are often mounted on a stand to block light or create shadows in a shot. Floppies are opaque flags that have extra lengths of fabric that can “flop” down when needed, or be attached to itself via velcro when not. Frames provide a location for cut pieces of gels or diffusion to be mounted. The size of both flags and frames can range from just a few inches to large rigs mounted from cranes over talent.
White Net and Black Net Flags can be used to lower the output of film lights.
Topper, Bottomer, Sider
Set speak for a flag that is placed close to the lighting source to remove light from part of the shot and reduce spill from a given side.
Gobo
The term derives from GO – Between – Optics. It’s a metal or glass pattern that can project shapes, shadows, textures, and images when placed inside a focusable fixture like an ellipsoidal. Often used on set to project blind shadows, custom logos, or the outline of foliage.
Using a Gobo to cast venetian blind shadows into the scene is just one example of how to use gobos in your film lighting setup.
Cucoloris
A large pattern, usually carved out of wood, that is placed at a distance from an artificial hard light source that can create similar gobo shadow effects, but needs additional grip rigging.
Blackwrap
Also known as “Cinefoil” or “Photofoil,” this useful matte black aluminum foil can be placed on a light (usually on the barn doors) to cut and shape the light. Available in 12”, 24”, 36”, or 48” wide rolls, It can also work as negative fill in some lighting setups.
Rosco Blackwrap is available in 12”x50’, 24”x25’, 36”x25’ and 48”x25’ rolls.
Bounce or Reflector
The purpose of a bounce or a reflector is to soften the light source. Bounces can be made of foam core materials, silver and gold reflective materials, or from the filming environment itself. Bounced light is difficult to control as it widens a beam substantially, but the effect on a subject can be very flattering. Keep in mind that the light beam may change color temperature after interacting.
A 6’x6’ reflector Butterfly mounted to a grip frame and a pair of C-Stands.
We live in the golden age of lighting. More fixtures with more features at lower price points are giving filmmakers something they crave most: the option to choose the light that serves the story and fits the pace of the project.
Which light is right for your project? A few things to consider:
Color
Does your project require a variety of colors? Should an RGB LED panel be used or perhaps colorful gels?
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A filmmaker used purpled colored Gels on their film lights to create a stylized nighttime scene for a horror movie.
Kelvin and Color Accuracy
Does the light replicate colors well? Is the Kelvin setting on the light what is actually being emitted? Is the fixture reading as too green or too magenta? Does it have +/- magenta control allowing you to compensate for a green or magenta shift, or will you need to rely on physical color correcting gels?
Daylight or Bi-Color
Daylight-only fixtures tend to have a higher output that, at times, can compete with the sun itself. Do you need that level of output or can you work with the added flexibility of bi-color lights that allow for a larger Kelvin range.
Overall Output
Is this a nighttime scene where you do not need to compete with ambient lighting and you’re using a light sensitive camera? Perhaps you don’t need a higher output fixture and you can work with a lower-output, cheaper fixture instead.
Power Draw
Do you have access to a generator or studio circuits, or will you be relying on house power in an urban apartment? Will you trip a breaker if you use anything over 1500 Watts?
Size
Do the lights and the modifiers needed to use that light fit through the door of your location? Is the fixture so heavy that it requires a larger crew than you may have initially considered?
Two Rosco DMG MAXI fixtures mounted on a Double MAXI Yoke can create a voluminous amount of light on set while remaining relatively lightweight and portable.
Control
Is it easy to control the light manually? Does the fixture have Bluetooth, wired or wireless DMX control?
Price Point
Of course we can’t leave price point out of the conversation. Does it make sense to purchase for long-term use or rent for a single production?
Accessory Ecosystem
Does the lighting fixture have accessories and modifiers available, or will your team need to consider creating custom options?
Build Quality
Can the light fixture hold up to the physical demands of the shoot? Can it withstand impact or dust and sand? Does it have large exterior vents that could allow particles to impede the delicate internal electronics? Is it waterproof or water resistant?
A lighting plot can be as simple as a 3-point interview setup (key, hair, and fill) or as complex as lighting a large multi-level soundstage to play as daylight with multiple triggered effects over DMX and a high powered HMI or multi-unit LED hard light acting as the sun. The most complex setups can involve literally hundreds of lights and many days of pre-lighting before a single second is put to film or memory card.
Note that a high CRI or TLCI average (Television Lighting Consistency Index) can be an indicator of a quality light source capable of accurately emitting colors, but many factors must be taken into account when judging the quality and potential of a lighting instrument.
All lighting fixtures are not created equal, and securing and understanding the right tools for your film lighting project is critical. Considering the points above will help you make the right decision.