Color grading is the process of altering and enhancing the color of film images, still video images or still images electronically, chemically or digitally. Gradation colors include color correction and making artistic color effects. Whether for theatrical film, video distribution, or print, the color gradation is generally now done digitally in a series of colors. The previous process of chemical photo film, known as color timer , was performed in a photography laboratory.
Video Color grading
Color timing
The earliest grading film technique, known as the color timer, involves changing the duration of the exposure process during the film development process. The coloring time is mostly used for color correction, but can also be used for artistic purposes. The color time is specified in the printer points. Because it can not be done in real time, the color timer for movie processing involves sufficient skills to be able to predict correct exposure. For complex work, "wedges" are sometimes processed to help pick the right judgment.
Maps Color grading
Telecine
With the advent of television, broadcasters quickly realized the limitations of live television broadcasts and they switched to broadcast feature films from print releases directly from a telecine. It was before 1956 when Ampex introduced the first Quadruplex video recorder (VTR) VRX-1000. Live television shows can also be recorded to be filmed and aired at different times in different time zones by recording video. The heart of this system is kinescope , a tool for recording broadcast television to movies.
Early telecine hardware is a "movie chain" for broadcasting of films and utilizing movie projectors connected to video cameras. As Jay Holben explains in American Cinematographer Magazine, "Telecine does not really become a viable post-production tool until it's given the ability to do color correction on video signals."
Currently, telecines are identical to color timings as tools and technologies have advanced to create color tinting (color correction) everywhere in the video environment.
How telecine staining works
In a cathode ray tube (CRT) system, the electron beam is projected onto a phosphor coated envelope, producing a single pixel size light point. These rays are then scanned across the movie frame from left to right, capturing the "vertical" frame information. The horizontal scanning of this frame is then completed as the film moves past the CRT rays. After this photon file penetrates the frame of the film, it finds a series of dichroic mirrors separating the image into the main components of red, green and blue. From there, each ray is reflected onto the photomultiplier tube (PMT) where the photon is converted into an electronic signal to be recorded onto the tape.
In a telecine charge-coupled device (CCD), white light shines through an open film image to the prism, which separates the image into three main colors, red, green and blue. Each colored light beam is then projected onto a different CCD, one for each color. CCD converts light into electronic signals, and telecine electronics modulate these into video signals which can then be judged color.
Initial color correction of the CRT Rank Cintel MkIII telecine telecine system is achieved by varying the main gain voltages on each of the three photomultiplier tubes to vary the red, green and blue outputs. Progress further transformed many color-processing equipment from analog to digital and then, with the next generation telecine, Ursa, a completely digital coloring process in a 4: 2: 2 color space. Ursa Gold produces color gradations in 4: 4: 4 color spaces.
The color correction control system started with the TOPSY Cptel Rank (Telecine Operations Programming SYSTEM) in 1978. In 1984 Da Vinci Systems introduced their first color corrector, a computer-controlled interface that would manipulate the color tension on the Rank Cintel MkIII system. Since then, technology has grown to provide tremendous power to digital dye. Currently there are many companies that make color correction control interface including Da Vinci Systems, Pandora International, Pogle, and more.
Some key functions of electronic color gradation (digital):
- Reproduces accurately what is captured
- Compensation for variations in material (i.e., film error, white balance, various lighting conditions)
- Optimize transfers for special effects use
- Create the 'look' you want
- Upgrade and/or change the scene of a scene - visually equivalent to the accompaniment of a movie's music; compare also film tinting
Note that some of these functions conflict with others; for example, color rating is often done to ensure that the recorded color matches the design set, whereas in the music video, the goal may be to form a stylish look.
Traditionally, color assessment is done for technical purposes. For example, in the Marianne film, judgments are used so that night scenes can be filmed cheaper by day. Secondary color correction was originally used to build color continuity, but current trends are increasingly moving toward creative goals, such as enhancing the aesthetics of the image, setting stylish looks, and setting the scene scene through color. Due to this tendency, some dyes suggest the expression "color enhancement" above "color correction".
Primary and secondary color grading
Primary color grading affects the entire image by providing control over the color density curves of the red, green, blue, channels across the entire frame. Secondary correction can isolate various hue, saturation and brightness values ​​to bring changes in color, saturation and luminance only within that range, allowing secondary color gradations, while having minimal or usually no effect on the rest of the color spectrum.. Using digital gradations, objects and color ranges in a scene can be isolated with precision and customization. Color tints can be manipulated and visual care is pushed to extremes that are not physically possible with laboratory processing. With this advancement, the process of color correction is becoming increasingly similar to established digital painting techniques, delivering a new era of digital cinematography.
Masks, matte, power windows
The evolution of digital color scoring tools has advanced to the point where colorists can use geometric shapes (such as mattes or masks in photo software such as Adobe Photoshop) to isolate color adjustments to specific areas of an image. These tools can highlight the wall in the background and only the color of the wall, leaving the rest of the frame alone, or coloring everything except the wall. The next color corrector (usually software based) has the ability to use spline-based forms for greater control over isolated color adjustments. Color keying is also used to isolate the area to adjust.
Inside and outside of area-based isolation, digital filtering can be applied to soften, sharpen or mimic the effects of traditional glass photography filters in virtually unlimited degrees.
Motion tracking
When trying to isolate color adjustments on moving subjects, dyes would have traditionally been required to manually move the mask to follow the subject. In its simplest form, motion-tracking software automates this time-consuming process using algorithms to evaluate the motion of a group of pixels. These techniques are generally derived from appropriate transfer techniques used in special effects and composition jobs.
Medium medium
The evolution of telecine devices into movie scanning allows digital information collected from negative films to be enough resolution to transfer back to the movie. In the late 1990s, the Pleasantville movies and O Brother, Where Art Thou? putting technology to the point that the creation of digital intermediates is possible, which greatly extends the capabilities of digital telecine dyes in a traditionally film-oriented world. Currently, many screen movies go through the DI process, while manipulation through photochemical processing decreases its use.
In Hollywood,
O Brother, Where Art Thou? is the first fully digitized film. Negatively scanned with Spirit DataCine at 2K resolution, then color is digitally tuned using Pandora MegaDef color corrector on Virtual DataCine. This process takes several weeks, and the resulting digital master is issued to record again with the Kodak laser recorder to create an internegative master.
Modern motion image processing typically uses digital cameras and digital projectors; when done correctly, color correction in such systems is a technical function that involves calibrating different elements of the system, leaving the color scoring process entirely on the creation of an artistic color effect.
Hardware-based versus system-based software
Hardware-based systems (da Vinci 2K, Pandora International MegaDEF, etc.) Have historically offered better performance and a smaller set of features than software-based systems. Their real-time performance is optimized for the resolution and depth of certain bits, compared to software platforms that use standard computer industry hardware that often trades speed for resolution independence, e.g. Apple's Color (formerly Silicon Color Final Touch), ASSIMILATE SCRATCH, Adobe SpeedGrade, and SGO Mistika. While hardware-based systems always offer real-time performance, some software-based systems need to be created as the complexity of color gradation increases. On the other hand, software-based systems tend to have more features like spline-based windows/masks and advanced motion tracking.
The boundaries between hardware and software obfuscate because many software-based color correction (eg Pablo, Mistika, SCRATCH, Autodesk Luster, Nucoda Film Master and Filmlight Baselight) use multi-processor workstations and GPUs (graph processing units) as hardware acceleration tools. In addition, some newer software-based systems use a group of multiple parallel GPUs on a single computer system to improve performance at the very high resolution required for feature film ratings. eg Blackmagic Design 'DaVinci Resolve. Some color assessment software such as Aperture Synthetic Aperture Color runs just as software and will even run on low-end computer systems.
Hardware
The control panel is placed in a color box for the operated colorist.
- For high-end systems, many telecines are controlled by Da Vinci Systems 2k or 2k Plus color correctors, also called color grading.
- Another sophisticated system is controlled by Pandora Int. Pogle, often uses the MegaDEF, Pixi, or Revolution color scoring system.
- In addition, the color scoring system requires an edit controller. The editing controller controls the telecine and VTR (s) or other recording/playback devices to ensure accurate frame frames. There are a number of systems that can be used to edit controls. Some color assessment products such as Pandora Int. Pogle has built-in edit controllers. Otherwise, a separate device such as the Da Vinci Systems TLC edit controller will be used.
- Older systems are: Renaissance, classical analogs, Da Vinci Systems: The Whiz (1982) and 888; 60XL Corporate Communications Systems (1982-1989) and Copernicus-Sunburst; Bosch Fernseh's FRP-60 (1983-1989); Dubner (1978-1985?), TOPSY System (1978), Amigo (1983), and ARCAS (1992) Cintel. All of these old systems work only with standard definition video signals 525 and 625, and are deemed to no longer work today.
Software
Controls are displayed on the screen and are sometimes accessed as plugins for host applications.
- The Baselight of FilmLight is used for HD, 2K, 4K and 3D color assessment. Class operation is controlled through Blackboard. The program supports various movie and video formats and codecs. The FilmLight system uses cluster and cloud technology in the Linux environment.
- Nucoda from Digital Vision provides advanced color rating tools that work with ACES and HDR in SDs up to 8K as well as industry-leading image recovery and enhancement tools.
- Software such as Aperture Synthetic Aperture Color runs as a plugin in a hosted application such as Apple's Final Cut Pro, After Effects and Adobe Premiere.
- Da Vinci Systems of Blackmagic Design operates on Mac OS X, Windows 7 Pro, and Linux OS utilizing a bunch of parallel GPUs for real-time assessment of HD, 2K and 4K images in 2D or Stereoscopic 3D.
- SpeedGrade from Adobe Systems was released as part of Creative Suite 6 and Creative Cloud works on both Mac and PC. It works on interface layers and workflows related to Premiere Pro and After Effects.
- Magic Bullet Colorista II from Red Giant Software offers multi-step color corrections with primary, secondary and master stages in host applications including Apple's Final Cut Pro, After Effects and Adobe Premiere.
- Grading Sweet is a special Color Grading plugin package for Apple's Final Cut Pro.
- Sony Vegas has many built-in filters as well as third-party plugins for color scoring.
- Apple Final Cut Studio 2 contains Apple Color which is a special software application for color assessment.
- Bones Dailies by Digital Film Technology
- Other programs have their own color scoring options (eg Edius or Blender).
- Autodesk Luster is a high-end color assessment solution. It features GPU acceleration for most functions.
- YUVsoft Color Corrector Adobe After Effects plug-in for Stereo3D color assessment.
- Mystika (SGO) is an online color and online rating system.
- The Pablo Rio Quantel color correction and resolution system is available only as a software or in various turnkey configurations.
- The Scratch assimilation has sophisticated color gradations and composite tooling and is used to create digital daylight and for final settlement. It runs in Mac and Windows environments.
- Movie Conversion is a simple color scoring tool that converts digital recordings to mimic the look of real movie stock
Gallery
See also
- One-light
- Color balance
References
External links
- Colorist Society International (CSI) - The Professional Body for Colourist
- TKColorist Internet Group
- Why You Need Color Correction, video by Terence Curren, senior dye at Apha Dogs, Inc.
- What a Color Can Do from a Photography Director? Interview with Ellie Ann Fenton
- Cinematic Color: From Your Monitor to Large Screen
- A Walk By The Digital Film Colorist... Revolution?
Source of the article : Wikipedia
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