Skip to main content
Aesthetics4 October 2024

Projecting at the Right Aspect Ratio: CST Expertise

By Pascal Montjovent

The choice of aspect ratio goes far beyond the technical format: it structures the visual experience. Projecting a film in the wrong ratio can distort the image, crop essential parts of the frame, or misplace subtitles, compromising the artistic intent and emotional impact.

The issue of aspect ratios is nothing new. Sergei Eisenstein was already concerned about it in 1930, particularly with the arrival of CinemaScope, fearing that the standardization of a new screen format would “paralyze” artists’ composition efforts.

Claire Denis illustrates this artistic freedom by often shooting in scope format (2.39:1), even for intimate narratives. In “Beau Travail” for instance, she plays on the contrast between the wide frame and the intimacy of interactions, enhancing the sensory experience.

Eric Cheriou, Technical Director of the CST, emphasized along with all panelists, during a conference at the CST, the importance of respecting each format, from the standard 1.85:1 to more unusual ratios such as 2:1 or even 1.55:1, as recently chosen by directors like Albert Serra or Quentin Dupieux. Every aspect ratio carries a specific intention, and altering it during projection means betraying the filmmaker’s vision.

Tips for Optimal Projection

One of the main topics discussed at the CST conference focused on masking and framing. For a screen equipped with variable masking, it is essential to properly calibrate the mask opening to match the projected ratio. For a fixed-frame screen, the projectionist must ensure the image is centered and correctly framed within the screen boundaries. When projecting a film in a ratio that differs from the screen format, properly managed black bars (letterboxing or pillarboxing) are preferable to stretching or cropping the image.

Using CST test patterns before each projection is a recommended practice: they allow verification that the masking is correctly calibrated, subtitles are well-positioned, and image geometry is preserved.

Looking Ahead with Dynamic Aspect Ratio

Another innovation discussed was dynamic aspect ratio, an approach that consists of varying the ratio within the same film, as practiced by Wes Anderson in “The Grand Budapest Hotel.” This technique creates a narrative immersion effect, with each ratio conveying a different era or mood. While this approach remains rare, it sparks growing interest among filmmakers and could become more common with advancements in digital projection and variable masking.

Masking and Framing: Precision Above All

Masking is a central tool for faithful projection. As one panelist explained, poorly managed masking can lead to partially visible subtitles or unintended image distortion. The CST provides specific test patterns and recommendations to the CST to avoid visual aberrations. Using test patterns to verify masking precision before each projection is a best practice that limits last-minute adjustments and ensures optimal image quality.

Precise management of ratios, whether standard or “exotic,” is a matter of technical know-how and attention to detail. Cinematographers, in collaboration with projectionists and properly equipped theaters, can thus deliver a visual experience faithful to the intention of the director and the audience. The CST continues to support this approach by providing tools, test patterns, and training to guarantee perfect projections, regardless of the chosen format.

To learn more and access calibration test patterns, consult the resources provided by the CST:

https://cst.fr/choix-ratio-image-projection

The video of the session is very informative:

https://youtu.be/tHzOBtjpG8A?si=btYyyv3b99wrs9_o

The following participated in the presentation and panel discussion:

  • Baptiste Heynemann: General Delegate of the CST
  • Jean-Baptiste Hennion: Managing Director of 2Avi
  • Thierry Beaumel: Co-representative of the CST Image Department
  • Eric Cherioux: Technical Director of the CST
  • Karim Dridi: Director of the film Revivre
  • Pierre Mazoyer: Cinematographer of the film L’homme d’argile
  • Tristan Frontier: Director of Operations at SND
  • Audrey Kleinclaus: Managing Director of NEC Display Solutions France

Best Practice Recommendations for Cinematographers Regarding Aspect Ratios

  • Master DCP container formats: particularly the DCP Flat (1.85:1) and Scope (2.39:1) container formats. From post-production onward, simulate the rendering of your image on both screen types to anticipate the impact of DCP encapsulation and refine your container choice with the director. Concretely visualize the black bars or potential cropping and adjust the image if necessary.
  • Communicate actively, beyond metadata: do not limit yourself to DCP metadata. Maintain proactive communication with the distributor and, if possible, with the exhibitor. For non-standard ratios, provide a specific CST test pattern and a technical newsletter explaining the artistic choices and recommended projection settings.
  • Accept the “exotic format” vs. “optimal projection” compromise: be aware that a non-standard ratio may compromise optimal rendering in certain theaters. Weigh the pros and cons with the director and accept that variations may occur despite all precautions.