Treating HD As A Film Stock

I really don't want to start a video V film battle again but I'm interested in looking at HD as if it was another film stock, i.e. what are it's contrast handling characteristics, what's it's tonal range like etc etc.

Geoff

Geoff,

The interesting thing about this question is that it raises one of the biggest differences between electronic imaging and film. With any video system, the format itself has very little impact on the contrast & tonal range, simply because the image is formed by the camera and not by the stock, whereas with film the image is formed by the stock and not the camera. So when people using video talk about cameras it most comparable to film people talking about stocks. My theory is that this is a major point of misunderstanding and conflict when people start comparing film and digital. Video people tend to talk very intensely about different cameras because this dictates the palette they have to work with. But to a film person this can often appear as useless technobabble.

So I guess my point is that in order to compare HD as a filmstock, you have to discuss specific cameras. (Made slightly easier at this stage by the limited number of HD models).

It's a very interesting topic, but I think we have to be careful when translating between film jargon & video jargon. Perhaps more significant is the different ways and effects of manipulating the image forming process in HD. The contrast and tonal range in almost all the newer cameras can be altered, just as the contrast and tonal range of a negative can be altered by using different techniques and processes.

So, there's my 2 cents (Aus) (or 0.9p (UK)) worth.

Cheers,

Ben "I've got an HD Bolex" Allan.

> Perhaps more significant is the different ways and effects of manipulating the image > forming process in HD.

Agreed.

I would like to know if a film transfer would pull more out of the shadows of HD than a is evident in a electronic projection or on a HD CRT. In respect to gammas, the latest digibeta and the new F900 can be switched between different curves at the touch of a button, so comparisons between curves are easily viewed. I have found this very useful. Although on paper some of the curves don't look that much different the results onscreen, to say, a flatly lit wall can be dramatic. How the curves compare to film stocks would be interesting and how DPs choose which stock/which curve even more so. In respect of digital, does one light the set then play with the curves or choose a curve and then light the scene?

Mike Brennan

>In respect of digital, does one light the set then play with the curves or choose a >curve and then light the scene?

Interesting question Mike,

I've always chosen the film stock for the look I want and then lit to that.

So I guess that I'd choose the curve and then light to that.

On the other hand well, I quite like the idea of lighting a scene the way I want and then changing the curves to fit it.

Unfortunately I doubt that any available digital imaging system could take the highlights!

Geoff

>How the curves compare to film stocks would be interesting and how DPs choose >which stock/which curve even more so.

I have no first hand experience with HD cameras but in "SD" the enhancement charachteristics of the cameras can play as much of a role in lighting choices e.g. hard/soft as do curves, gamma.. For instance, Video cameras love softly graduated transistions. Throw something harder at them - and - what ? (For an example of what DOESN'T work well in HD, look at the HD scene from "The Phantom Menace" )

If I were going to shoot/light for HD, ONE question in my mind would be: how much of the ability of this camera to acheive sharpness is in the CCD chips and how much is in the enhancement circuitry and can and should this enhancement be manipulated ? And then, how ? If not electronically, then we are going to want to use filtration to defeat certain tendencies of the HD camera. And, diffusion, after all, provides a select combination of in-focusness and out-of-focusness. So, now we are up against the amount of "reserve sharpness" (i.e. ability to create contrast in the image AS wanted) available from the HD Camera. As compared to film - we can make fine looking images, but we are walking on a tightrope to do so.

i.e. if you're going to compare HD to a film stock you're going to have to pay as much attention - conciously or intuitively - to MTF curves as you do to charachteristic curves and gamma, I think.

-Sam

Hello!,

A am afraid that it will take still a VERY long time until any electronic on-set capturing/recording device will be able to handle this! You just gave a exemplairy example of one of the things where the perfomance of film origination and electronic origination are furthest apart!

With todays existing electronic capturing you probably would have lost this shot.

Electronic cameras force you to grade 90% on the set. They can not (yet?) record more dynamic range than needed for projection, like a negative film does. This makes electronic capturing expensive and cumbersome in a lot of situations.

If we would like to compare HD to film stock, then we should compare it to a REVERSAL stockat best! (or a neg printed to a positive assuming we DO NOT change printerlights more then 5 points).

Beste regards

Kommer Kleijn

VFX Cinematographer

Brussels, Belgium, Europe

Stop Motion, Motion Control, Stereography, Digital Imaging

>Video people tend to talk very intensely about different cameras because this >dictates the palette they have to work with.

What's more, most of the 'electronic cinematography' cameras have setup cards that allow the user to change so many parameters on the camera, you really have to talk about those setups in combination with specific cameras!

Great for the DP, who can create his own 'look,' but it also makes it very hard to draw comparisons. I've never used my D600 in anything approaching factory presets....

George Hupka

Director/DOP

Downstream Pictures Saskatoon, Canada

Having shot HD practically on a daily basis (The Secret Adventures of Jules Vernes among other projects) for a bit more than a year, I could go on and on about this thread and some comments but... been there and done that... so I won't.

A simple answer; IMHO, HD (at it's present state) is as if you were using film stock from 10-15 years ago, that had a lot less latitude and in many cases more contrast (that sort of goes togheter does it not:-)). A lot of great images were shot with those film stocks. Rate it at around 250-400 iso.

My two cents

Daniel Villeneuve, c.s.c.

Directeur-Photo, Director of Photography

Montréal, Canada

http://www.aei.ca/~davil

Thank you Daniel,

You have far more practical experience with HD than most of us and I was hoping that you would post.

I saw quite a few sequences from Jules Verne at the BKSTS weekend and they looked great, now that seems to be a project where appropriate technology was used!

I only saw a couple of shots where extreme highlights had caused a clipped look.

I think we'd be grateful for any more you have to say on this topic.

Geoff