etimh wrote:Its physics, for pete's sake.
OK, let's talk physics.
Both film and video pass light through a lens producing an image on a sensitive medium (i.e., film or CCD). That image is described by three functions
R(x,y,t); G(x,y,t); B(x,y,t)
where
x,y are coordinates on the sensitive medium
t is time
R is the intensity of light over a small range of frequencies centered on the frequency where the average human is most sensitive to red light
G and B similarly defined for green and blue.
The purpose of film and video is record the functions R, G, B and to use that record to produce another image at time t' = t + T described by
R'(x',y',t') = k[R]R(x,y,t)
G'(x',y',t') = k[G]G(x,y,t)
B'(x',y',t') = k
B(x,y,t)
where x',y' are the coordinates on the emitting medium.
and T is the length of time between the time the image is acquired and the time it is displayed.
Ideally k[R] = k[G] = k = constant.
But in practice
k[R] != k[G] != k and is not constant. (!= means not equal)
Not only not constant but functions of their respective indices.
k[R] = k(R); k[G] = k(G); k = k(B)
These three functions define "film look" and "video look."
Now engineers can either try to develop a system where k[video] is a constant, i.e., they can try to reproduce nature, or then can try to develop a system such that
k[film] - k[video] < S
where S is a value small enough that the human eye/brain cannot tell the difference.
If engineers can meet this challenge then they can produce video that cannot be distinguished from film.
