Reducing Light

Learn how to reduce the overall light output of a fixture.

There are a number of tools available to reduce either the overall light output from a light source, or to reduce the brightness on a particular part of the object you’re lighting.  Most gaffers will choose a light source that is slightly larger than what is needed, then reduce the brightness using one of the methods listed below.  This gives them flexibility should it become necessary to bright the light source – instead of taking the time to replace the light with a higher-wattage head, they can simple pull the scrims.

Wire Scrims

Wire scrims are circular metal meshes that, when placed in between the light and barndoors, reduce the overall brightness of the light. Every light has its own set of scrims and include:

			Single Scrim Singles reduce light by ½ an f-stop			Half Single Scrim A single half scrim reduces the light by ½ an f-stop, but the wire mesh only covers half the open frame
			Double Scrim Doubles reduce the light by 1 f-stop			Half Double Scrim A double half scrim reduces the light by 1 f-stop, but the wire mesh only covers half the open frame

Nets

Nets are light-reducing fabric stretched across an open rectangular frame.  Usually held in place with a C-stand, nets can be placed closer or farther from a light source, allowing a grip to isolate particular areas of the subject.  Most nets are open-ended, meaning one edge of the net has no metal support.  This allows the grip to feather the light grade by raising and lowering the open part of the net into the light, without risk of a shadow caused by the frame. Nets are available in several densities.Solids – Solids are metal frames covered with duvatyne, a light-blocking fabric.

The most common sizes for nets and solids are:  12”x18”,  18”x24”,  24”x36”

48”x48” – Also called 4’x’4’, 4×4 are among the most common-size solids, used to block large light sources such as the ambience from a window, or to block the spill onto a wall from a soft light.  4×4 floppies include an additional 4’x4’ piece of duvatyne sewn on one edge and Velcroed to the remaining three, so when opened, the effective area is 4’x8’.

 

Cutters

Cutters are long narrow solids intended to block the top and bottom of a light source, allowing a grip to focus the light onto a subject.  For example, when shooting a medium shot of an actor, use a bottom cutter to reduce the key light on the actor’s chest, and a top cutter to reduce the light off the top of the actor’s head to draw the audience’s attention to the actor’s face. Cutters are most commonly used in the following sizes: ·

10”x42” cutter,  18”x48” cutter,  24”x72” cutter

Dimmers

Dimmers are rheostats that, by varying the voltage to a light source, can reduce, by dimming the light. When using dimmers, be aware of the following:·

• Don’t overload the dimmer – Make sure the dimmer is rated for the wattage of the light you’re using.  Dimmers on set are generally rated for 650 watts, 1000 watts or 2000 watts.
• Be aware of the color temperature change – The more you dim a tungsten light, the warmer the color temperature becomes.  Although the effect is negligible when dimming up to 25%, further dimming will noticeably change the color of the light.
• Not every light can be dimmed – Dimmers are generally used on tungsten lights only.  Kino-flos, HMIs, and other light sources requiring ballasts cannot be dimmed with traditional dimmers.

Neutral Density (ND) Gel

• ND gels are applied over windows to reduce the brightness of the outside light without tinting it.
• Once the gel has been measured, use a spray bottle of soap and water to help the ND gel adhere to the glass.  Use a squeegee to eliminate any bubbles.

Key Light Techniques

The key light is the most important light on set. It’s purpose isn’t just to illuminate the actor, but to help accentuate the emotion of the character in each and every scene. When looking at the key light, there are two major factors to consider: What direction does the key light come from, and how much does it wrap around the face?

• Direction – The direction of the key light is often guided by the direction of the ambient light on set, although the key light can be placed practically anywhere. As a general rule of thumb, try to avoid placing the light close to the axis of the lens. This will fully illuminate the front of the actor, wiping out the natural shadows that contour and shape the face. The result is neither flattering nor glamorous. The general guide is to position the key light roughly 45 degrees to the left or right of the axis of the camera lens… but how far?
• Wraparound – Sometimes a key light can be the harsh, untreated fixture, or it is heavily diffused. The degree of diffusion and wraparound depends heavily on the type of actor being lit and the overall cinematic look.

Lighting Techniques

• Women (beauty/glamorous look) – Position a large key light such as a 2,000 watt tungsten, or a 1.2k HMI slightly more frontal than usual about 6-8 feet away from the actor, and raise the key light roughly 12″ above her eye line. Clip light diffusion like opal or 250 and 1/4 CTO (to warm up the light) to the barndoors. Then place a 6×6 heavy diffusion like gridcloth or bleached muslin 3-4 feet from the actor. This lighting tends to accentuate the cheek bones , lips and chin while filling in wrinkles around the eyes. Combined with a light pro-mist filter in front of the lens, this lighting is very flattering to women.
• Women (Standard look) – Try using a Kino-Flo wrapped with opal, and place 45 degrees from the lens axis. Then, place a 4’x4′ frame of 250 diffusion to further soften the light. This light, while slightly harsher than the beauty lighting tends to bring out more of the texture of the face, and creates a large eyelight.
• Men – (Standard look) – Use a 1k tungsten light through a 4’x4′ frame of 250 diffusion just off the lens axis as the main key light, then, add another 1k tungsten light through 4×4′ 250 frame focusing on the same side, but closer. This “stacked” key light approach creates a realistic look that both sculpts the face without accentuating wrinkles or skin imperfections.
• Men and Women (Sculpted) – An outstanding technique, especially when the actor’s eyeline is far from the lens access it to illuminate the far side of the actor’s face with a high, focused key. Assuming the actor is looking frame right, set up a 1,000w tungsten light through a frame of 250 diffusion just to the right of the camera. Then place a 650w tungsten light with 250 clipped to the barndoors focusing on the left side of the actor’s face. Raise the light so it is 2-3 feet above the actor’s eyeline. Notice how the key almost serves as a rim light, bringing out the contours and shape of the actors face. This lighting setup also creates an outstanding eyelight.
• Bouncing the Key – The key light doesn’t always need to be directly focused onto the subject. Some of the most beautiful light is reflected, and one of the most common ways to do this is by using a piece of 4’x4′ bead board, available at your local hardware store. The soft beaded texture of this styrofoam creates a soft diffused light without a lot of specularity.
• Low Ambience – For creating a key in low light situations, set-up a 1,000w or 2,000w light on a turtlebase with a 5/8″ baby pin adapter and focus it straight up into a 4×4 beadboard mounted at a 45 degree angle. Control the softness of the light by spotting or flooding the light source, and by walking the bead board closer or farther from the subject.
• High Ambience – For environments with high ambience, place the light fixture on a baby stand at eye level and aim it across the axis of the camera lens into a beadboard placed at a 45 degree angle. The light can be positioned as close as the outside edge of the frame, although a lenser may be necessary to reduce any reflection of the light source onto the camera lens.
• UltraBounce – To create an even softer key light, focus a large light source into a 6’x6′ UltraBounce. Although the light output won’t be as great as if the light were directly focused onto the subject, the reflected light will be softly wrapped around the subject, especially if the 6×6 is walked closely to the subject. Combine this tech with an additional key light coming from the side to add a little more edge to the look.

 

 

 

 

“Cinematography & Lighting” – Gregg Toland (Week 1 Lecture Notes)

by Gregg Toland

The camera, when you get right down to cases, is the eyes of the audience. Thus the cameraman is the censor (I dislike the word but it is applicable here) over the most important of the five physical senses of millions of entertainment seekers. Great is his crime, artistically speaking, if he violates this trust by failing to present in the most telling manner the dramatic content of the plot.
The cameraman’s further responsibilities are both artistic and economic, inasmuch as he is a factor in an art-industry.

From the art side of the picture, there are three things he must know:

1. The mechanics of the camera.
2. Where to place the camera, and,
3. How to light the scene to be photographed.

The first is purely routine. The second and third functions involve the creative ingredient. The placement of the camera determines the angle from which the action is to be viewed by audiences. The importance of this angle to dramatic effect cannot be overemphasized. The lighting of the scene is an equally potent factor in the determination of dramatic effect, in addition to its basic function—visibility.

To the eye of an expert cameraman, the manner in which a set is lighted is an infallible key to the mood to be established. He can step onto a lighted set which he has never seen before and predict with astonishing accuracy what kind of scene is about to be photographed.
Toland on Cinematography (BlackBoard Item)//

Week 4 | Blackboard Assignment

• SCREEN:  “A TOUCH OF EVIL”,
• READ: the lecture notes, and
• CONTRIBUTE: your ideas to the related discussion.

For those who have not yet contributed to the SUNRISE discussion group:

In the Film/Video category of the upper left window, click on the SUNRISE folder and the link it contains.  Watch the film and begin a discussion of its visual atmospheres.  Pay particular attention to the various “in camera” special effects, and to how imaginative they are and to how difficult they must have been to invent.

Begin a discussion in the SUNRISE thread to share your ideas.

Considering that FAUST was Murnau’s last German film and SUNRISE his first American film, what similarities and differences do you notice?

Continue your discussion group on Light and Exposure.  Study the handout on the subject from Week 2.  I want everyone to understand the concept of the chart.

To prepare for our first shoot, please read and understand the methods to prepare the camera and make proper exposures.  There is a handout from last week on this subject.  We will be using the Arriflex SR Camera and the Sekonic Exposure Meter.  It is now becoming essential that you understand the process, so you should know the handouts, Preparation and Shooting, and those for the camera and meter.

Week 3 | Blackboard Assignment

Please continue with the discussions.

ARRI SR 2

There is a new discussion entitled ARRIFLEX SR AND BOLEX H-16R CAMERAS. Please participate.

Although I am very impressed with the currently ongoing discussions in CITIZEN KANE and VISUAL STORYTELLING METHODS, we could have much better participation in all forums.

Your participation will help improve the “Class Participation” part of your grade…but, even more importantly, it will keep you thinking about course content and make you more adept at problem solving when we begin shooting.

Bolex R16

For those of you who have not yet done so, please locate in Film / Video, the CITIZEN KANE clips and their corresponding Filmstrips. Under the video clips, I ask some questions and ask you to provide your thoughts with regard to specific frames in the Filmstrips. After doing that, expand the discussion with your own research and speculation about those details.

Also, if you have not yet done so, find the link in the film/video catagory to the 1926 F.W. Murnau production of FAUST, view the entire film and contribute to a group discussion on the subject of its visual atmospheres.

This week’s film is F.W. Murnau’s SUNRISE: A SONG OF TWO HUMANS. Watch it and participate in the group discussion. For reference, please review last week’s lecture notes.

Please don’t hesitate to express your inability to understand something, especially with regard to the more technical items we are covering…but also with the aesthetics. Others will help you with that in these forums.