Day for night is a set of cinematic techniques used to simulate a night scene while filming in daylight. It is often employed when it is too difficult or expensive to actually shoot during nighttime. Because both film stocks and digital image sensors lack the sensitivity of the human eye in low light conditions, night scenes recorded in natural light, with or without moonlight, may be underexposed to the point where little or nothing is visible. [1] This problem can be avoided by using daylight to substitute for darkness. When shooting day for night, the scene is typically underexposed in-camera or darkened during post-production, with a blue tint added. Additional effects are often used to heighten the impression of night.
As film stocks and video cameras have improved in light sensitivity, shooting day for night has become less common in recent years. [2] (A cultural reference as early as 1934 appears in Cole Porter's Anything Goes where a list song of the same name includes the observation, "and day's night today.")
Although moonlight is not blue, it appears bluish to the human eye due to the Purkinje effect. [3] Photographers in the late 19th century exploited this effect by using various chemical techniques to adjust the contrast and color of pictures. Stage productions similarly adopted the use of blue-tinted lighting to illuminate night scenes. This convention continued with silent films, which required a well-lit scene to capture images at the frame rate but often tinted night scenes in blue. To give a bluer appearance to scenes filmed in color, some techniques use 3200K tungsten-balanced rather than 5000K daylight-balanced film stock. [4] The tungsten balance renders artificial lighting (street lights, headlights, lit windows, etc.) as white and unlit areas as "moonlight blue." With professional video cameras, color temperature adjustments are made to achieve the same effect. With digital post production now nearly universal, the color temperature adjustment is usually made in camera, to preserve the "white" artificial lights, but scene darkening is left to post production for finer control of the effect.
Underexposing the shot can add to the illusion of darkness or moonlight. It is typical to underexpose by about two f-stops. [5] A neutral-density filter is often used to achieve this darkening, so that the camera aperture remains unchanged.
Daytime sky can be darkened to simulate night. With black and white film, a red lens filter will turn a blue sky black. Infrared film is occasionally used for long shots, but it renders green foliage as white. Yellow or orange filters (Wratten 8 or 15) can be substituted for closer shots, to preserve the performers' flesh tones. With color film or video, a graduated neutral-density filter can achieve a similar effect, as can a polarizing filter. Using either of these filters can limit camera movement during a shot, as the axis of a graduated filter must match the horizon, and the effect of the polarizing filter changes as the axis of the camera lens moves relative to the sun. [6] If the scene is backlit by the sun for a "moonlight" rim light effect, faces and other foreground details may be too dark to see properly. Partially filling shadows with reflectors or a 5000K (daylight-balanced) key light can compensate for this. [6] [1] Even so, shadow areas are still slightly under-lit, to match the higher contrast of the overall scene.
With digital post-production techniques it is also common to add or intensify glare and light scattering from light sources that would otherwise be less pronounced in daylight, such as windows revealing indoor lighting, outdoor artificial lights, car headlights, and so on. Day for night techniques can be made more convincing through such digital effects. It is possible to digitally replace the entire sky to add the moon and stars, as was done for the film Cast Away . [4] For the 2015 film Mad Max: Fury Road , an unusual variation of the technique was used, in which scenes were deliberately overexposed, rather than underexposed as is typically recommended. Taking advantage of the dynamic range of the digital cameras used on the production, the shots were then darkened and color-graded a bluish tint in post-production, with the result that detail was maintained in the shadows rather than being clipped, as might happen when underexposing. [7]
Instead of shooting during midday, it is also common to shoot at dawn or dusk. During these periods, car headlights, streetlights, and interior lights are on, as they would be at night. [1] This is sometimes referred to as "dusk for night." Shooting this way can be difficult because the desired lighting conditions last only a short time, during which both light levels and color temperatures are constantly changing. [8]
A similar technique can sometimes be observed in older hand-tinted postcard views, where a "night" view of a scene is created by simply re-tinting the original (black and white) photo with darker coloration, suggestive of night. [9]
Though the results resemble day for night film and video shots, the techniques are quite different. Instead of reducing the exposure of the print made for the night version, the colorist painted an identical print with darker individual tints. No attempt at an overall bluish effect was made, and many colors are actually warmer in the "night" scene. (Compare the two beach umbrellas.) Convincing bright hot spots were added to the streetlights, which are unlit in the original, and the sky was supplied with fewer, wispier clouds.
A related technique is night for day, where an interior location is shot at night but lit to simulate daylight, often by projecting large lights through windows. [10] [11]
Color temperature is a parameter describing the color of a visible light source by comparing it to the color of light emitted by an idealized opaque, non-reflective body. The temperature of the ideal emitter that matches the color most closely is defined as the color temperature of the original visible light source. Color temperature is usually measured in kelvins. The color temperature scale describes only the color of light emitted by a light source, which may actually be at a different temperature.
Film stock is an analog medium that is used for recording motion pictures or animation. It is recorded on by a movie camera, developed, edited, and projected onto a screen using a movie projector. It is a strip or sheet of transparent plastic film base coated on one side with a gelatin emulsion containing microscopically small light-sensitive silver halide crystals. The sizes and other characteristics of the crystals determine the sensitivity, contrast and resolution of the film. The emulsion will gradually darken if left exposed to light, but the process is too slow and incomplete to be of any practical use. Instead, a very short exposure to the image formed by a camera lens is used to produce only a very slight chemical change, proportional to the amount of light absorbed by each crystal. This creates an invisible latent image in the emulsion, which can be chemically developed into a visible photograph. In addition to visible light, all films are sensitive to X-rays and high-energy particles. Most are at least slightly sensitive to invisible ultraviolet (UV) light. Some special-purpose films are sensitive into the infrared (IR) region of the spectrum.
The film industry is built upon many technologies and techniques, drawing upon photography, stagecraft, music, and many other disciplines. Following is an index of specific terminology applicable thereto.
Chroma key compositing, or chroma keying, is a visual-effects and post-production technique for compositing (layering) two or more images or video streams together based on colour hues. The technique has been used in many fields to remove a background from the subject of a photo or video – particularly the newscasting, motion picture, and video game industries. A colour range in the foreground footage is made transparent, allowing separately filmed background footage or a static image to be inserted into the scene. The chroma keying technique is commonly used in video production and post-production. This technique is also referred to as colour keying, colour-separation overlay, or by various terms for specific colour-related variants such as green screen or blue screen; chroma keying can be done with backgrounds of any colour that are uniform and distinct, but green and blue backgrounds are more commonly used because they differ most distinctly in hue from any human skin colour. No part of the subject being filmed or photographed may duplicate the colour used as the backing, or the part may be erroneously identified as part of the backing.
In photography, exposure is the amount of light per unit area reaching a frame of photographic film or the surface of an electronic image sensor. It is determined by shutter speed, lens F-number, and scene luminance. Exposure is measured in units of lux-seconds, and can be computed from exposure value (EV) and scene luminance in a specified region.
Cinematography is the art of motion picture photography.
In the United States, Canada and the United Kingdom, grips are camera support equipment technicians in the filmmaking and video production industries. They constitute their own department on a film set and are directed by a key grip. Grips have two main functions: The first is to work closely with the camera department to provide camera support, especially if the camera is mounted to a dolly, crane, or in an unusual position, such as the top of a ladder. Some grips may specialize in operating camera dollies or camera cranes. The second function is to work closely with the electrical department to create lighting set-ups necessary for a shot under the direction of the director of photography.
Grips' responsibility is to build and maintain all the equipment that supports cameras. This equipment, which includes tripods, dollies, tracks, jibs, cranes, and static rigs, is constructed of delicate yet heavy duty parts requiring a high level of experience to operate and move. Every scene in a feature film is shot using one or more cameras, each mounted on highly complex, extremely expensive, heavy duty equipment. Grips assemble this equipment according to meticulous specifications and push, pull, mount or hang it from a variety of settings. The equipment can be as basic as a tripod standing on a studio floor, to hazardous operations such as mounting a camera on a 100 ft crane, or hanging it from a helicopter swooping above a mountain range.
Good Grips perform a crucial role in ensuring that the artifice of film is maintained, and that camera moves are as seamless as possible. Grips are usually requested by the DoP or the camera operator. Although the work is physically demanding and the hours are long, the work can be very rewarding. Many Grips work on both commercials and features.
In photography, bracketing is the general technique of taking several shots of the same subject using different camera settings, typically with the aim of combining the images in postprocessing. Bracketing is useful and often recommended in situations that make it difficult to obtain a satisfactory image with a single shot, especially when a small variation in exposure parameters has a comparatively large effect on the resulting image. Given the time it takes to accomplish multiple shots, it is typically, but not always, used for static subjects. Autobracketing is a feature of many modern cameras. When set, it will automatically take several bracketed shots, rather than the photographer altering the settings by hand between each shot.
In photography and cinematography, a filter is a camera accessory consisting of an optical filter that can be inserted into the optical path. The filter can be of a square or oblong shape and mounted in a holder accessory, or, more commonly, a glass or plastic disk in a metal or plastic ring frame, which can be screwed into the front of or clipped onto the camera lens.
In photography, the metering mode refers to the way in which a camera determines exposure. Cameras generally allow the user to select between spot, center-weighted average, or multi-zone metering modes. The different metering modes allow the user to select the most appropriate one for use in a variety of lighting conditions. In complex light situations professional photographers tend to switch to manual mode, rather than depending on a setting determined by the camera.
In television, film, stage, or photographic lighting, a fill light may be used to reduce the contrast of a scene to match the dynamic range of the recording media and record the same amount of detail typically seen by eye in average lighting and considered normal. From that baseline of normality, using more or less fill will make shadows seem lighter or darker than normal, which will cause the viewer to react differently, by inferring both environmental and mood clues from the tone of the shadows.
Color correction is a process used in stage lighting, photography, television, cinematography, and other disciplines, which uses color gels, or filters, to alter the overall color of the light. Typically the light color is measured on a scale known as color temperature, as well as along a green–magenta axis orthogonal to the color temperature axis.
Tungsten film is photographic film designed to accurately represent colors as perceived by humans under tungsten light; the more usual color films are "daylight films", balanced to produce accurate colours under direct light from the sun or electronic flash. Tungsten film was developed for photographers who use tungsten lights, also known as photofloods, which have a much lower color temperature than daylight, at 3200 kelvins or 3400 kelvins. It also renders colors more accurately than daylight film under ordinary household incandescent lighting.
Film tinting is the process of adding color to black-and-white film, usually by means of soaking the film in dye and staining the film emulsion. The effect is that all of the light shining through is filtered, so that what would be white light becomes light of some color.
In optics, a diffuser is any material that diffuses or scatters light in some manner to transmit soft light. Diffused light can be easily obtained by reflecting light from a white surface, while more compact diffusers may use translucent material, including ground glass, teflon, opal glass, and greyed glass.
Redscale is a technique of shooting photographic film where the film is exposed from the wrong side, i.e. the emulsion is exposed through the base of the film. Normally, this is done by winding the film upside-down into an empty film canister. The name "redscale" comes because there is a strong color shift to red due to the red-sensitive layer of the film being exposed first, rather than last [the red layer is normally the bottom layer in C-41 film]. All layers are sensitive to blue light, so normally the blue layer is on top, followed by a filter. In this technique, blue light exposes the layers containing cyan and magenta dyes, but the layer containing yellow dye is left unexposed due to the filter. E-6 film has also been used for this technique.
A colour cast is a tint of a particular colour, usually unwanted, that evenly affects a photographic image in whole or in part.
Landscape photography shows the spaces within the world, sometimes vast and unending, but other times microscopic. Landscape photographs typically capture the presence of nature but can also focus on human-made features or disturbances of landscapes. Landscape photography is done for a variety of reasons. Perhaps the most common is to recall a personal observation or experience while in the outdoors, especially when traveling. Others pursue it particularly as an outdoor lifestyle, to be involved with nature and the elements, some as an escape from the artificial world.
Articles related to the field of motion pictures include:
This glossary of motion picture terms is a list of definitions of terms and concepts related to motion pictures, filmmaking, cinematography, and the film industry in general.