Color correction by using gel color, or filter, is a process used in stage lighting, photography, television, cinematography, and other disciplines, whose purpose is to change the overall color of light; usually bright colors are measured on a scale known as the color temperature, as well as along the orthogonal green-magenta axis to the color temperature axis.
Without color correction gel, the landscape may have a mixture of various colors. Applying the color correction gel in front of the light source can change the color of the various light sources to be matched. Mixed lighting can produce undesirable aesthetics when displayed on television or in the theater.
In contrast, the gel can also be used to make the look more natural by simulating a naturally occurring color temperature mixture. This app is useful, especially where motivated lighting (lends the impression that it is a diegetic) is the goal. Color gel can also be used to color the lamp for artistic effect.
Video Color correction
Certain colors from a white light source can be simplified to a correlated color temperature (CCT). The higher the CCT, the lighter the light appears. The sunlight at 5600K, for example, looks much more blue than tungsten light at 3200K. Unlike chromaticity diagrams, the Kelvin scale reduces the color of the light source into a single dimension. Thus, light sources from the same CCT may appear green or magenta compared to each other [1]. Fluorescent lamps, for example, are usually very green when compared to other types of lighting. However, some fluorescents are designed to have high loyalty to ideal light, as measured by color rendering index (CRI). This dimension, along a constant CCT line, is sometimes measured in terms of green-magenta balance; This dimension is sometimes referred to as "tint" or "CC".
Maps Color correction
Gel Nomenclature
The main color correction gels are CTB (blue color temperature) and CTO (orange temperature color). A CTB gel converts tungsten light to 'day' colors. A CTO gel does the opposite. Note that different manufacturer gels produce slightly different colors. In addition, there is no precise definition of daytime color as it varies depending on location (latitude, dust, pollution) and daylight hours.
The gel that removes the green scratch from the fluorescent lamp is called minus green . The gel that adds a green cast is called plus green . Fractions like 3/4, 1/2, 1/4, and 1/8 indicate gel strength. The 1/2 CTO gel is half the strength of the CTO gel ( full ).
White balance camera
Color filters can be applied over the camera lens to adjust the white balance. In video systems, white balance can be achieved by digital or electronic manipulation of the signal and hence the color correction filter is not entirely necessary. However, some digital cinema cameras can record images without any digital filtering being applied. Using a physical color correction filter for white balance (not digital or electronic manipulation) can maximize the dynamic range of the captured image [2].
Some professional cameras designed for ENG use filter wheels containing color correction filters and are designed to optimize performance for different color temperatures.
In film cameras, no electronic or digital manipulation of white balance is possible in the original negative camera. Color correction filters are an effective method for adjusting white balance. Without filtering, one should attempt to fix the white balance by coloring the time or by manipulating the film after being scanned or telecined.
References
Source of the article : Wikipedia
0 Comments