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Comment by sudosysgen | Hacker News Reader

Which makes me think, what prevents me from putting a lens in front to the projector and directly imaging the projection into a camera sensor? Modern cameras can record lossless 48bpp equiv. video in 4K, it would pretty much be a 1:1 copy given sufficiently sophisticated optics.

Which leads me to the conclusion that the only reason why no one is ripping movies using Prima Cinema projectors and commodity grade hardware is the price. If they removed DRM it wouldn't make much of a difference, the limiting factor is already the price of the projector.

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I honestly think that DRM is very much like antivirus in the sense that the only reason anybody buys into it is that the companies who develop it pay sales reps to convince corporations that it's something they need when it's really just poisonous snake oil and paying money to someone to shoot you in the foot.

Well, there's some practical considerations - getting the refresh rate sync'd up, avoiding or filtering moire patterns out, getting the colors and such just right, things like that. However, it's possible enough that most theater projectors already have DRM restrictions that shut the system down if you start fiddling with the image path. The password to authorize an image path change is only handed out to supervisors. Evidently, access to such codes were so uncommon that, during the 3D movies era of last decade, most projectionists wouldn't bother swapping out 3D stereographic filters for 2D showings because it would require getting management involved.

Modern cameras will actually automatically sync their shutter rates to any flickering light sources. As for colors, they are designed to let you apply lookup-table based corrections by providing huge amounts of color information you can correct later.

Crucially, this approach wouldn't trigger anything because all of the equipment would work outside of the projector. You would add the lenses and camera aligned and just after the projector. In effect, the system would take the place of the screen in the image path. I don't know of any protected image screen that can detect tampering.

The movies are probably watermarked, so they'd know who leaked them, and then sue the leakers for all they're worth.

This is how some video game demos are managed. Subtle color variations are used throughout the game window to uniquely finger print each copy of the game during media blackout.

Indeed. There are, however, ways around that.

I would be surprised if there wasn’t a theater projectionist in the warez scene that has a setup like the one you describe.

DRM is ridiculous because consuming the product is a side channel.

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