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class="Paragraph" Lighting Ratios

Published : 22nd April 2004


Just out of curiosity... does anyone here think in lighting ratios?

I don't. Saying you are lighting to a 4:1 ratio doesn't actually say anything about how you are exposing the film stock. But maybe someone here can tell me if they actually think this way and whether it works for them.

Art Adams, DP [film|hdtv|sdtv]
Mountain View, California - "Silicon Valley"
http://www.artadams.net/



Art Adams wrote :

>Just out of curiosity... does anyone here think in lighting ratios?

I don't, at least not as you describe. I find it much more effective to shoot extensive exposure and latitude tests and determine the various looks and emotions and what ratios would be best for each, but in terms of stops over exposure and stops under exposure rather than as am X:1 ratio (recently on a project I did I decided that scenes of high tension would be lit with a key that was 3 stops over and a fill that was 4 stops under. This way I knew what I was getting, and that it would fit the mood of the film).

This works really well for me, but I'm sure everyone has their own methods.

Will Beckley
Northwestern University
Cinematography Senior



Art Adams wrote :

>Just out of curiosity... does anyone here think in lighting ratios?

It can be useful for having someone do a pre-light, or for teaching about contrast.

Steven Gladstone
www.gladstonefilms.com
Cinematographer - Gladstone Films
Cinematography Mailing List - East Coast List Administrator
Better off Broadcast (B.O.B.)
New York, U.S.A.



What I was really getting at -- given the same scene if you shot and like a fill level on a persons face that was 2 stops under what you are exposing at on a stock such as 7293. And now that this stock is no longer available, a possible substitution would the much lower contrast stock, Vision 2 200T would you lower the fill level to get a achieve a similar result.

I guess the point I'm trying to understand is if you adjust how you light a face depending on the latitude and contrast of the stock.

Nick Anthony
Aspiring DP



>Just out of curiosity... does anyone here think in lighting ratios?

That's exactly how I think, in T-stops and ratios - though I am learning to think in footcandles.

Brent Reynolds
DP
Tampa FL



>That's exactly how I think, in T-stops and ratios - though I am learning to >think in footcandles.

Interesting. I'm totally Zone System myself. I'm doing the "light by eye and figure the exposure out later" thing. So far it's worked pretty well, although it can make matching an exciting exercise. It works marvellously in natural light settings, and most of the time I light to make locations look naturally lit, so...

The thing with working intuitively is you have to do it all the way. If you only go half way you'll screw yourself up... as I've discovered.

Art Adams, DP [film|hdtv|sdtv]
Mountain View, California - "Silicon Valley"



>That's exactly how I think, in T-stops and ratios - though I am learning to >think in footcandles.

Interesting. I'm totally Zone System myself. I'm doing the "light by eye and figure the exposure out later" thing. So far it's worked pretty well, although it can make matching an exciting exercise. It works marvellously in natural light settings, and most of the time I light to make locations look naturally lit, so...

The thing with working intuitively is you have to do it all the way. If you only go half way you'll screw yourself up... as I've discovered.

Art Adams, DP [film|hdtv|sdtv]
Mountain View, California - "Silicon Valley"



Do you find that other aspects of the zone system work in film cinematography? Such as the way pull and push processing are described? Such as bringing just a highlight from zone IV to zone VIII by pull processing 1 stop.

I have never read any motion picture DP talk about it that way. Usually have read that these techniques are used in movies for a particular look that is desired.

Nick Anthony
Aspiring DP
SF



Developer time variations are often used to affect the contrast and tone scale of B&W negative films:

http://www.kodak.com/US/plugins/acrobat/en/motion/products/curves/ti0299b.pdf

But for the ECN-2 process, "push" and "pull" processing are usually not primarily used to control contrast, but rather to make an under or over exposed negative print more like a normally exposed and processed negative:

http://www.kodak.com/US/en/motion/support/processing/push.shtml

John Pytlak
EI Customer Technical Services
Eastman Kodak Company
http://www.kodak.com/go/motion



A real expert and proponent of the "Zone System" is John Dowdell, Chief Colorist/Engineer at Technicolor Creative Services in NYC.

John is an alumni of the Rochester Institute of Technology, and worked closely with tone reproduction expert Richard Zakia:

http://www.photography01.com/product/0871000407/AsinSearch/5/

http://www.photoshoproadmap.com/product/0871000407/AsinSearch/2/

He also was a close witness to the WTC attack on September 11, 2001:

http://www.rit.edu/~newsshare/messages/68.html

John Pytlak
EI Customer Technical Services
Research Labs, Building 69
Eastman Kodak Company
Rochester, New York 14650-1922 USA