The Importance of Proper Cinema Projection and Color Grading
One common issue occurs with dark scenes, which can appear washed out or greyish, especially in 2D movies projected on 3D silver screens with excessive light levels. This problem is exacerbated when the film’s color grading is performed on monitors that are too bright, resulting in a loss of contrast when projected in dimmer cinema environments.
To maintain a cinematic look and feel, many filmmakers prefer to employ traditional 35mm film grading techniques. This approach helps avoid the dreaded “video look” that can make a movie appear less professional or immersive.
Hollywood productions often utilize specific color schemes and visual techniques to enhance perceived contrast and create a more engaging viewing experience. One popular method is the “Orange and Blue” color palette, which leverages complementary colors to make scenes pop and add depth to the image.
To ensure optimal viewing conditions, cinemas should:
- Carefully calibrate projector brightness and contrast settings
- Use the standard 14 fL light level
- Use appropriate screens for 2D and 3D projections
- Regularly maintain and clean projection equipment
As a viewer, being aware of these factors can help you appreciate the artistry behind film production and seek out theaters that prioritize high-quality projection standards.
The Impact of Film Emulation and Color Systems on Digital Cinema
When applying film emulation 3D LUTs (Look-Up Tables) to digital video, you may notice a desaturated effect. This occurs because colors that fall outside the gamut of 35mm film are mapped to values within the film’s color range. It’s important to note, however, that 35mm film can display highly saturated dark colors effectively.
Digital cinema and traditional 35mm film use fundamentally different color systems:
- Digital Cinema: Additive Color System
- Combining all colors results in white
- Can display bright colors beyond film’s capabilities
- 35mm Film: Subtractive Color System
- Combining all colors results in black
- Some colors appear less bright due to light absorption by multiple color layers
- Can show saturated dark colors.
The Xenon P3 color space, developed for film grading, offers more saturated primary colors than the standard REC709 space. While P3 can better represent the saturated colors of red, orange and violet, it’s still an additive system capable of displaying brighter colors that were impossible with traditional film.
Key differences between digital and film color reproduction:
- Digital cinema can show extremely bright colors unachievable on film
- Some colors on 35mm film appear less bright due to the layering of color filters
Recent trends in filmmaking have seen an increase in the use of brighter colors for dramatic effect. This shift is partly due to the digital cinema version often serving as the master from which other versions are derived. Consequently, a 35mm print of such films may look noticeably different from its digital counterpart.
Understanding P3 Color Spaces in Digital Cinema
The SMPTE RP 431-2:2011 D-Cinema Quality Reference Projector and Environment standard outlines four distinct P3 color spaces, each with its own white point:
- P3 D55
- P3 D61
- P3 D65
- P3 DCI WHITE
Key Points:
- Compatibility: All four color spaces fit within the gamut of a P3/Virtual White digital cinema projector. D61 is the one that is closest to the white point of 35 mm film.
- Artistic Freedom: Filmmakers have the liberty to choose any artistic white point for their productions. There’s no obligation to use DCI WHITE.You could choose a colder D65 or warmer D61 or even use D61 inside D65.
- No Mandatory Chromatic Adaptation: It’s not necessary to apply chromatic adaptation to the DCI WHITE white point. This allows for greater creative control and flexibility in color grading.
Implications for Filmmakers and Colorists:
- Understanding these different P3 color spaces can help in making informed decisions during the color grading process.
- The choice of white point can significantly impact the overall look and feel of a film.
Best Practices:
- Communicate clearly with post-production teams about the intended color space and white point.
- Experiment with different white points to achieve the desired artistic effect.
By understanding these nuances in P3 color spaces, filmmakers and colorists can make more informed decisions, leading to better control over the final look of their productions in various digital cinema environments.
Understanding Color Space Conversion: REC709 to DCDM X’Y’Z’
Converting from monitor-graded REC709 to DCDM X’Y’Z’ isn’t a straightforward process due to fundamental differences in viewing conditions:
- DCDM X’Y’Z’:
- Display-referred gamma-encoded color space
- Designed for digital cinema projectors
- White point: 14fL/48 cd/m²
- Viewing environment: Dark
- Monitor REC709:
- White point: 80-120 cd/m²
- Viewing environment: Dim
For accurate conversion, grade REC709 material in a cinema environment with 14fL/48 cd/m² brightness.
Key DCDM X’Y’Z’ specifications:
- 12-bit depth (4095 levels)
- Maximum luminance: 48 cd/m²
- Normalizing constant: 52.37
- Gamma: 2.6
DCDM X’Y’Z’ is based on CIE XYZ 1931 with DCI primaries (currently P3), gamma-encoded at 2.6.
Important considerations:
- Verify your software uses correct conversion parameters to avoid color shifts (e.g., white appearing pink).
- DCI White isn’t necessary for mastering, as DCDM X’Y’Z’ supports other standard color temperatures like D61 or D65.
- Prioritize correct contrast over using P3 colors; REC.709 colors are acceptable.
Remember: Proper contrast is more crucial than using the full P3 color gamut. Focus on achieving the right look for your project within the constraints of your target display system.
REC2020: The Future of Digital Cinema Color Space?
The evolution of color space in digital cinema is an ongoing process, with REC2020 emerging as a potential future standard. This development could significantly impact how we experience movies in theaters and at home.
Current Standard: DCI XYZ with P3 Primaries
- Reference projector: Xenon-based
- Minimum Color Space Gamut: P3 primaries
Emerging Standard: REC2020
- Standardized for TV industry
- Reference projector: Laser-based
- Coverage: 99% of visible colors to humans
- Learn more: Rec. 2020 on Wikipedia
Potential Implications for Digital Cinema:
- DCI X’Y’Z’ standards could be upgraded to incorporate REC2020 primaries
- Minimum Color Space Gamut may shift from Xenon P3 to RGB Laser REC2020
- Post-production facilities would need to transition to RGB Laser projectors
Challenges and Solutions:
- Existing Xenon projectors in cinemas would require color mapping from REC2020 to P3
- Two DCP (Digital Cinema Package) versions might be necessary:
a) One for Xenon projectors
b) One for RGB Laser projectors
Benefits of RGB Laser Projectors:
- Higher contrast ratio
- Wider color gamut
- Brighter image
The transition to REC2020 in digital cinema would represent a major leap in color reproduction capabilities. However, it would also require substantial investments in new equipment and workflows throughout the industry. As the technology matures and becomes more accessible, we may see a gradual shift towards this more expansive color space, ultimately enhancing the visual experience for moviegoers.
Filmmakers, colorists, and cinema owners should stay informed about these developments to prepare for potential changes in color grading and projection technologies.
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Hello,
I follow your blog regularly. thanks for all the info that you have here. Helps us a lot.
Regarding the above post, I have a doubt.
If my film was graded in REC709 Full Range, with a peak white at 100 cdm2, and I use a LUT to go from REC709 to DCI-P3, what should I expect for the peak white levels ?
The theater expects a peak white of 14fL, which is around 48cdm2. Will the LUT change the peak white, or rather the grading has to be done at REC709 viewed at peak white of 48cdm2, given that it will be a darkened room ?
Thank you for your time.
The lamp should calibrated to 14/48cdm2 fL white illumination in the cinema. It used to be a problem that cinemas had dim lamps, now higher values like 100 cdm2 can be seen on 3D/2D screens. 100 cdm2 in a dark room is very bright and black will be more grey at those levels. If you grade on a 100 cdm2 monitor you should remember that white will not be as bright and 0 black in cinema is not 0 black like on a plasma screen. 0 black will always look a bit grey without some brighter areas in the picture that creates some contrast.
So how about if we grade with 48cdm2 on a an lcd tv, in a darkened room ? Would that simulate a theatre ?
Basically, is there a way we can simulate all properties of a theatre on an lcd/plasma screen in a room ? I know the diferrences between them as in: theatre being fully dark, peak white at 48 cdm2, gamma 2.6, and a white point of DCI white.
Is it possible that the plasma/lcd be calibrated to these specs and veiwed in a fully dark room ? Would that be a WSIWYG config, leaving just the gamut differences of DCI-P3 and REC709 ?
thanks,
Computer monitors and cinema screens are different. The rods and cones in the eye will react different to a monitor and a cinema screen. But you could compare the monitor and the cinema and the monitor will get you some idea of how it will look in the cinema. A Plasma screen on eco mode or a monitor adjusted to 48 cdm2 will still have blacker blacks than a cinema theatre. You could try to simulate the greyer blacks of a cinema with the brightness control. You should use 2.6 gamma in a dark room and 2.4 in a dim room. A smaller cinema screen or monitor will have more colorful colors than a larger cinema screen even if the colors are calibrated the same. You could try to compensate for this.