CodeBlocks

Sunday, 5 January 2014

Hollywood still uses film

It might come as a surprise to know that the majority of major hollywood films are still shot using analog film. Inception, Dark Knight, Star Trek into the Darkness, Man of Steel are a small sample of movies still shot in film [link]. 

And at first glance you might think its silly to still use film, after all film productions is significantly more expensive. The film needs to be developed(creating the negatives) then turned into digital content via a film scanner, before they can add in any CGI. Not to mention the costs of developing the film alone to be displayed.

“It costs about $1,500 to print one copy of a movie on 35 mm film and ship it to theaters in its heavy metal canister. Multiply that by 4,000 copies — one for each movie on each screen in each multiplex around the country — and the numbers start to get ugly. By comparison, putting out a digital copy costs a mere $150.” [Link]

If film is more expensive and harder to work with, why do they still use it? One reason is that film is analog and is not really subject to resolution boundaries like digital. The reason why they can remaster Indiana Jones, Star Wars (4,5,6) and all those other old films to HD(1920x1080) is because all they have to do is rescan the negative at a higher resolution. Where as with digital you're stuck with the resolution you shot in. So when 4k(3840 x 2160) comes out the old movies will be rescanned at sold again and when 8k(7680 x 4320) comes out its the same process.

Of course there is a limit to how much resolution you can get out of an analog film. Theoretically all you have to do is:  ((lpm * w * 2) * (lpm * h * 2)) / 1 000 000 = Mega Pixel count [link]
Where:
lpm = lines per millimeter
w = width of film in millimeter
h = height of film in millimeter

So according to that a 35mm(academy ratio) film at 160 lines per millimeter would result in ((160 * 22 * 2) * (160 * 16 * 2))/ 1000000 = 36MP

This is of course assuming perfect conditions which never occurs in the real world. And other have done side by side comparisons between the two. It turns out that in practice 35mm film is about 9MP and if you take Kenrock Well's lie factor into account its 18MP [link]. Digital film cameras are not yet at that level, although the gap is narrowing and more films are being shot in Digital [link] such as the Hobbit shot using the RED digital camera.

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