stopstupidfxxkingscreenings.com

Stop stupid fxxking screenings.

You plug your computer into the projector. You extend the desktop. You play the film in VLC or QuickTime Player.

Chances are the audience won't see the film the way the team finished it. Not every time. But often, and for three reasons.

Reason 1 of 3

Gamma

Gamma is the speed at which the image comes out of the blacks.

Between the file and the projector, the player and the operating system can change that curve without telling you. The image comes out of the blacks too fast, or too slowly.

What the audience sees
Too bright, with grey, milky blacks. Or too dark, with crushed shadows.
Where to spot it
In a night scene.
blackwhite the signal light on screen
  • too bright ≈ 2.0
  • as graded 2.4
  • too dark ≈ 2.8
Same file, three curves. The middle one is the one the grade was signed off on.

Reason 2 of 3

Gamut

Gamut is the colour of the colours.

A video master is made in a precise colour space, nearly always Rec. 709. When the computer drives the projector as a screen, the operating system's colour management steps in. It converts the image for the profile it assigns to the projector, and nothing guarantees that profile is the right one.

What the audience sees
Hues shift. Reds, skies, and above all skin.
Where to spot it
On a face in close-up.
460490520560600700 nm
  • Rec. 709: the film's colour space
  • Display P3: what the system thinks it's talking to
Example: the system thinks it's talking to a Display P3 screen, the projector works in Rec. 709. Colours lose saturation and their hue moves.

Reason 3 of 3

Frame rate

A film is 24 or 25 frames per second. A computer is often 60 Hz.

With an extended desktop, the computer sends the projector its own display refresh rate. 60 isn't a multiple of 24: one frame stays up for 3 refreshes, the next for 2, and so on. Frames no longer last the same time. At 25 frames per second, same problem.

What the audience sees
It stutters.
Where to spot it
On the end credits roll of a well-finished film. It should glide up in one piece. Here, it moves in jerks.
The film: 24 frames per second A 41.7 msB 41.7 msC 41.7 msD 41.7 ms The computer: 60 Hz A 50 msB 33.3 msC 50 msD 33.3 ms One line = one refresh at 60 Hz, i.e. 16.7 ms.
A sixth of a second, four frames. At 24 frames per second, each one lasts 41.7 ms. Sent at 60 Hz, they last 50 ms and 33.3 ms in turn.

The fix, for years to come

under€200

A small video output device sends the projector a real video signal. At the film's frame rate, in the film's format, without going through the system's colour management.

The kit

DaVinci Resolvefree version€0
UltraStudio Express Monitor 3GSDI and HDMI outputs≈ €170
An SDI or HDMI cable≈ €15
Total< €200

Prices incl. VAT, seen in Europe. You need a Mac or PC with a USB4 or Thunderbolt 4 port.

In practice

  1. Install DaVinci Resolve and Desktop Video, the device's driver. Both are free.
  2. Plug the device into the computer, then into the projector over SDI or HDMI.
  3. In Resolve, create a project at the film's frame rate, 24 or 25 frames per second, before importing the file.
  4. In the preferences, pick the device as the video output. Hit play.

The projector needs to be set up properly too. But at least the signal it gets is the right one.

The question you'll get

What about DCP?

A DCP (Digital Cinema Package) is still more reliable. It's the cinema format, made and tested for this.

But from a ProRes 422 HQ master, this chain gives excellent quality. Far closer to a DCP than to a badly done screening.