digital intermediate technology

March 5, 2004

hi

can any one explain in detail what is digital intermediate processing and how far it is superior to regular processing?

venkat

David Mullen ASC · March 5, 2004

It's a "process" but not really a form of "processing" (i.e. development, etc.)

It's not so much about being a superior process but one that allows you to shoot on film - thus gaining the benefits of film image capture - and combine that with the flexibility of digital color-correction and image manipulation. So in that case, there isn't exactly a film equivalent to compare it to.

The other advantage is that it is a form of duplication that does not further increase graininess or contrast -- in fact, one can digitally suppress grain and reduce contrast, although not without some artifacts. Most film-based duplicating steps increase contrast and grain.

However, if you have a film image that can be duplicated normally with just contact-printing (no blow-ups, etc.) and doesn't need any digital color-correction tricks, then it's harder to make the argument for doing a digital intermediate if you don't need to take advantage of what it can do for you that is unique compared to film.

Filip Plesha · March 5, 2004

Do people usually reduce grain compleatly or just reduce it to

more peasant amounts?

Grain gives a lot of character and texture to the image if it is not to big

but is it comonly totally unwanted among filmmakers?

Michael Nash · March 5, 2004

I think it's completely different for each film and filmmaker. Much of the time grain becomes a distracting "veil" between the viewer and the subject, and want your images to be as unimpeded by artifacts as possible. Other times grain is deliberately used as a texture, even when going through a DI. Check out "21 Grams" or "Thirteen" (shot on Super-16). There was a trend in the 1990's in music videos especially to amp-up the grain as an expressive device. These days there's a lot of that slick look, and lens flares are the "in" thing. So trends can also influence what visual artifacts and devices filmmaker might choose, and grain is just one of them.

But even when going through a DI there's still the subtle, almost imperceptible grain in the print. Even with the cleanest DI, a film print will always restore a little of that subtle film look. Optical and chemical technques like blowing up Super-35 or Super-16, push-processing and silver retention only add more grain to the image. So if you only want a LITTLE bit of grain, sometimes you err on the side of making the image as clean and grainless as possible, knowing that there will always be some there.

Filip Plesha · March 5, 2004

And what about projects of digital film restoration ?

Old films from 60's and 50's have a lot more grain than today's films.

Altering that grain in restoration would raise some

ethical questions i think.

David Mullen ASC · March 6, 2004

Yes, there are all sorts of ethical conundrums when restoring old movies. Sometimes though you aren't working with the original negative but some grainier dupe, so grain reduction might get you closer to the original look. Sometimes different stocks used in the production have aged at different rates, so what used to match grain-wise now mismatches.

In the case of restoring "Roman Holiday" for example, they made the somewhat controversial decision to remove the grain digitally but then record it out to b&w camera negative stock to add back a consistent grain structure.

Generally, though, there's no such thing as a free lunch -- i.e. there are consequences to removing too much grain. Most of the best D.I.'s have used a light touch when it came to digital grain reduction processing. In other words, don't just shoot on the grainiest push-processed stocks thinking that with a D.I. you will make everyone think you shot it on 5245...

The advantage to digital restoration isn't so much grain REMOVAL but the ability to create a duplicate negative without getting increased graininess due to generational loss. Most standard optical methods of restoration involved making dupes and thus increasing contrast and grain more than the original had.