Anyway, to clear the things a bit more. This is a very popular analogy:
Take your SLR film camera, shoot the same subject under sam light several times
using different exposure setting on the camera, each time increasing the exposure by one stop
(open the iris by one stop). Give it to the lab, they will process the negative and
make prints out of each of these frames. All the prints are going to be identical in
sense of exposure. The minilab printer meters avarages every exposure on the paper.
The negative has a very wide range of tones, and it is up to filmmaker to decide
what smaller range is he going to extract out of the negative for his prints.
For example, you shoot a scene of a man in a room filled with daylight comming through the windows.
The difference between the shadowy interior and a sunshine lit exterior is HUGE.
You are exposing for the interior details.
The negative will record the interior details as well the exterior seen through the window.
So if you print that scene to print film for projection at normal printer setting, you will
get the image as you exposed it: white windows with almost no detail, and well exposed interior
showing normal colors.
But if you set the printer to a different setting, you can have a black interior with no detail,
and a normaly exposed exterior showing the scene outside the window with normal colors.
So basicly , you could say that you can "squese" two normal (viewing contrast) images into
one image on the negative. The range is that big.
In other words, the original negative holds a LOT of brighter tones than the brightest tone
on the cinema print (pure white).
That is the main reason for all the lightsabre troubles in the new DVD's. Some people think
that they recolored the cores so that they are pink rather than white now.
They didn't, they just used a different "printer setting" for the original image.
The pure white you see on the screen is not the brightest color in the negative.
So a film transfer is just a matter of chosing your white point and your black point in
this greater range.
The new DVD's are "printed down" a bit, the white point has been moved a lot higher,and
because of that you can see a lot more detail in the white corridors, bright sabres and other
bright tones that you did on previous transfers. This is basicly a good thing because
you can always go from higher dynamic range to lower (more punchy blown out highlights) by
making your own adjustments, but you can't go the other way around.
You can't retrieve a blown out highlight from a video file.
I think people expect the original "elements" (as they put it in articles) to be like some sort of
slides that you can look at on a lightable and see the "right" color balance and contrast.
But if you broke in the Lucasfilm vault, you would find unusable orange, ultra low contrast
images that require color timing and show nothing about the original color balance.
So what I was really trying to say is that people who are trying to restore the trilogy to its original
look need to be more specific about what do they consider to be "original" color and contrast.
Here is a perfect example:
If you took the original camera negatives of the scenes in Jabbas palace or sandcrawler interior
and scan them on a film scanner, you would not get what you see in cinema or video transfers.
Instead you would see a brightly lit scene where there were hardly any deep shadows.
All those sets were lit very brightly (it was 100ISO film for ANH and ESB) with strong lights,
and exposed as that. The images were then darkened in post production in the stage of color timing.
It was Lucas's creative decision. The Jabba's palace looks dark in the preprint copies, and in the prints.
But it is bright in the originals. Film is exposed for shadows usually, so what you see as shadows
in the print were actually normal mid tones on the set and in the originals.
So the question of what is original is quite a phylosophical issue.