clamped values in films

[Hugh]

The brightest value possible when projecting an image onto a cinema screen is determined by the brightness of the lamp in the projector.... This may well not be as bright as the object is in real life...

[mister3d]

Ok, let me show you. This is the same movie " Constantine" :

http://k.foto.radikal.ru/0705/b4/c01868e25b28.jpg

[Hugh]

Probably something to do with the transfer to DVD.....

Take a look at this (http://www.digitalgypsy.com/vfxlog/archives/2005/07/constantine_dvd_1.php) - it specifically talks about the colour in the DVD of Constantine...

[mister3d]

Probably something to do with the transfer to DVD.....

Take a look at this (http://www.digitalgypsy.com/vfxlog/archives/2005/07/constantine_dvd_1.php) - it specifically talks about the colour in the DVD of Constantine...

Thank you for the link Hugh!
So it really must be a DVD transfer with "Constantine".
Then the question is simple: may it be any reason to make such a clamping intentionally to achieve a special effect by it?

[jbills]

if the special effect desired is a bad comp!

for the most part, you'd want to keep any light sources in frame as they were photographed - it's just how they appear in real life, no matter how weird it might look.

but sure, I mean you do things like day for night grades and things like that where you're minimizing highlights and things. and you get the occasional director who likes to "art direct" what was actually shot to try to divert the eyes of the viewer (say the light source is really distracting). that's valid in some instances, but it's really hard for any compositor to agree with something that would never happen in real life. that's our job!

[mister3d]

if the special effect desired is a bad comp!

for the most part, you'd want to keep any light sources in frame as they were photographed - it's just how they appear in real life, no matter how weird it might look.

but sure, I mean you do things like day for night grades and things like that where you're minimizing highlights and things. and you get the occasional director who likes to "art direct" what was actually shot to try to divert the eyes of the viewer (say the light source is really distracting). that's valid in some instances, but it's really hard for any compositor to agree with something that would never happen in real life. that's our job!

Thank you for the explanation Jbills. This field is very not clear to me, so this all is very interesting!

[Hugh]

You may get this effect on film comps if the comper (accidentally) clamps the values between 0 and 1 when in linear - or changes it to 16-bit or something similar.

If this kind of thing ever happens, it should really be picked up by the supervisor - I'm sure it never happened on Constantine, anyway....

[beaker]

Hello, I want to ask why, as I can see, in many shots bright areas, as lights, are not full bright as in real life, but sometimes (and it seems often) almost half of their value. So it's interesting to know how this is achieved and what for.
Thank you.Umm, because the director said so.

[ExP]

Here a few other reasons:

-- One could be a problem when scanning the film in 10bit Log files and later applying the wrong 8bit downsampling LUT (look up table).

-- Or sometimes practical lights (lights you actually see on camera) may flare if they are too intense and/or flicker and/or interfere with the lighting of the shot that anyway comes from film balanced off-screen lighting fixtures.

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