[Frameworks] Film and Digital for beginners

[Aaron F. Ross]

Pip, my understanding is that old-school analog video had about seven 
stops of latitude. Current generation digital video cameras have 
about nine stops of latitude. If you shoot in RAW, then you 
effectively get the same latitude as film.

Digital cameras and projectors are not really linear. There are many 
stages of gamma compression and expansion in the signal chain from 
image capture to presentation. The system is designed to produce an 
image that looks "linear" to the viewer. But, of course, the 
characteristic S-shaped response curve of film is easily reproduced 
in the digital grading process. If you're seeing clipped whites and 
muddy blacks in a digital projection, someone wasn't doing his job correctly.

Aaron




At 7/14/2012, you wrote:
>Hi Jonathan, One technical difference people don't often mention is 
>sensitivity curves. Film has a logarythmic, S-shaped curve, to 
>capture information across 12 f-stops. For example, on film, a sunny 
>scene on a bridge with action in the sun and also in the shadows 
>under the bridge, all will be captured on the negative which has 
>great latitude. Video formats are linear, the curve is straight, and 
>you will have to shoot for the lights or for the darks - I think the 
>spread is about 3 f-stops. Newer high-end video cameras like the Red 
>can shoot in log, like film, but all video projection devices are 
>linear, so either the image is compressed for projection, or the 
>information can be put back out onto film. Even on the best and 
>biggest 4K projection system, one can see burned out whites and 
>muddy blacks because there is no information in those regions. 
>Someday the corporations that push new technology on us every two 
>years in order to stay profitable will force every movie theatre in 
>the world to buy logarythmic projectors and we will all have to 
>remaster our films (for the fifth time) on 12bitlog. Another 
>difference is flicker. Remember that film and video both are only 
>slide shows - each frame on the screen is static, unlike reality 
>which is always in motion. Seeing a film on a film projector with a 
>shutter creates a psychophysical experience called the phi 
>phenomenon which induces the illusion of motion. For a video 
>projection, the illusion of motion is created by a different brain 
>phenomenon called the beta effect. The difference between these two 
>experiences in the brain is so completely fundamental yet is always 
>overlooked when comparing the two technologies (continuous versus 
>discrete stimulation). In film, the apparent motion occurs only 
>during the fraction of a second when the screen is black - the brain 
>fills in the gap, building a bridge from frame to frame, in the 
>darkness, much as our brain creates dreams during the blackness of 
>night between two days. Beta effect happens in the retina, the brain 
>participates less in the process of observation. One could be bold 
>and say film wakes us up while video puts us to sleep. But in the 
>end I think the difference is not about what it looks like, but 
>rather about what it is. We use the word "image" flippantly. Is a 
>painting an image? Students may think they've scene the Mona Lisa or 
>a Kubrick film because they've seen them online, but a painting has 
>weight and texture, a film has grain and material, and that is what 
>we are seeing - not just the image of it. -Pip Chodorov At 16:42 
>-0400 13/07/12, Jonathan Walley wrote: >SO NOW, THE QUESTION: what 
>would you say are some of the most >important, and most fundamental, 
>differences between making and/or >seeing "films" in these two 
>media, in terms that intro-level >undergrads can understand and 
>appreciate. _______________________________________________ 
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Aaron F. Ross
Digital Arts Guild