Screening formats guide

Blu-ray
  • It is a revolution: for the first time in the history of cinema, the public can access a medium of a quality close to that achieved in post-production. VHS and DVD introduced great changes, but they remained poor quality media compared to digital masters or film.
  • Le Blu-ray a à la fois le meilleur rapport qualité-prix, et le support le plus susceptible de poser problème en projection (voir partie Inconvénients).
  • quality
    08
  • reliability
    03
  • flexibility
    09
  • widespread in big cinemas
    05
  • widespread in small cinemas
    07
Benefits
  • Quality: close to that of the master, high definition, high fidelity
    During the second screening of Screening Formats, guest viewers noticed the amazing absence of differences between the HDCAM and Blu-ray versions prepared by
  • Reproducible at a low cost
  • Can be watched with or without subtitles
  • Supports surround sound (5.1, 7.1)
  • Accessible to small theatres (if equipped with an HD projector). Theatres equipped with a low definition projector (SD, Standard Definition), would do better to use a specially encoded SD Blu-ray than to leave resizing from HD to SD to the Blu-ray player.
Disadvantages
  • difficult to project: Blu-ray contains anti-copy projection devices (HDCP). It is therefore impossible for projectionists to digitally integrate it into their normal video circuit.
    To be able to handle many different formats, film rates and media, most movie theatres and festivals are equipped with machines to modify the signal, convert formats, go from one frame to another, correct keystoning… These machines are generally not compatible with the HDMI output of Blu-ray players.
    Therefore, many theaters use an analog component signal. This signal can be obtained:
    • either from the Blu-ray player itself (but due to pressure from the majors, the latest players refuse to transmit an HD signal in analogue).
    • or by using an HDMI/analog converter such as HdFury
  • 24p: the 24fps, the usual rate in the cinema industry, is supported by the Bly-ray but
    • only after having specifically adjusted the Blu-ray player to send the 24 frames per second as such (by default, many players will send 25 frames, which will lead to judder)
    • only in HDMI: analogue 24fps does not exist. Therefore the Blu-ray player and the projector must be wired in HDMI
  • Some cinema projectors are specifically designed not to support the HDMI signal of a Blu-ray, precisely in order to avoid that cinema owners screen disks they have found on the market and have not bought from the distributor at a high price.
  • Fragile: Blu-ray has exactly the same appearance as a DVD or a CD. It therefore shares the same weaknesses: easy to scratch, attracts dust.
  • HDMI: the only digital output of a Blu-ray player is usually HDMI. It is a general public rather than a professional format. It is relatively uncommon for cinema projectors and does not do well over long distances (more than a few meters), unlike SDI.
  • son surround : la plupart des lecteurs Blu-ray ont une sortie stéréo analogique, et envoient le son surround via la sortie HDMI. Il faut donc un système pour extraire le son multi-canal du HDMI et l'envoyer au système d'écoute. C'est un appareil courant dans les Home-Cinema, plus rares dans les salles obscures.
  • Practically speaking, all these drawbacks show that Blu-ray is the support most likely to be problematic when screened. If one has a choice between sending a DCP or a Blu-ray to an unknown theatre, DCP is a much safer choice.
    This said, the only problems that ever occurred with Blu-rays made by occurred in places that were not used to projecting blu-rays correctly.
  • Requires a special mastering in order to obtain the highest quality, especially for masters which originate from difficult sources (ex: S16mm for the grain, Red for banding, etc.)