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Zone System as applied today


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#1 Ben Brahem Ziryab

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Posted 04 February 2016 - 01:11 AM

Hey guys,

 

I have pondered over the Zone System and how it can use be used to determine proper exposure, based on normal development of the negative. 

 

Most spot meters (not just the Zone IV modifications) will use a interval of one on the meter scale, which equals doubling or halving of the luminance, or "one stop".

 

Every one-stop change is a change of one zone on the exposure scale.

 

So, if the subject area reads 7 on Zone V, but you want it to fall on Zone III, you simply dial your meter two steps to the left. Simple enough.

 

The conundrum is this: Let us assume that we are scanning the negative, not adding contrast and not making a print. A negative, when scanned, has around 14 stops of dynamic range, so the distance in stops from the toe of the curve to the shoulder is 14 steps.

 

In addition, Zone 0 to Zone X represents a full range from pure black to pure white -- not the dynamic range. The dynamic range only refer the useful values that lies between Zone I to Zone IX, whereas the textural range is from Zone II to VIII. 

 

The Zone System uses a value scale of 10 (Zone 0 to Zone X) -- a 10 exposure scale from pure black to pure white.

 

So, how can we anticipate/visualize the negative density value using the Zone System on a 14 stop negative?

 

Perhaps the Zone System can be modified, so we increase or reduce the exposure by one and a half stop for each zone placement over/under Zone V. In other words, use one and a half stop intervals instead of one-stop intervals. On this scale, a Zone 0 rendering would fall seven and a half stops below Zone V.

 

Thanks.

 

Ben


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#2 David Mullen ASC

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Posted 04 February 2016 - 01:36 AM

I don't see how this helps in determining the proper exposure compared to just taking some meter readings and making a choice based on the brightness of the subject that you want. To me, what makes the Zone System interesting was how it coordinated exposure with a photographic idea of manipulated contrast to achieve a desired tonal range, but this makes more sense in b&w printing of stills. In motion picture work, it's hard to apply beyond simple notions of increasing contrast in flat situations and decreasing contrast in high contrast situations.
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#3 Ben Brahem Ziryab

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Posted 04 February 2016 - 02:05 AM

David,

 

What if you want to light a hallway behind the subject so parts of it appear black (but not pure black, more like a Zone I that is minimum density) and without the light falling off, while your subject's skin is significantly brighter than middle grey. How would you systematically approach something like that using your light meter and knowledge of the film stock?


Edited by Ben Brahem Ziryab, 04 February 2016 - 02:08 AM.

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#4 David Mullen ASC

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Posted 04 February 2016 - 11:28 AM

Lighting is a different issue, you can control tonal range with lighting.  Once I tested a stock and knew the tonal range I got for the typical release format gamma (Rec.709 video, film print, whatever) then I'd know when it fell to black or burned out to white for that gamma (more limited than the negative's range).  So then when I was lighting, I'd know how dark to make a shadow versus how hot to make a highlight, with the knowledge that if I was doing digital color-correction, I'd have some room for manipulation.

 

But otherwise, your testing would tell you that, let's say, 4-stops under on your spot meter was near black but with some faint detail in the print, and maybe you've decided that the face should be 1-stop over in that scenario.


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#5 John E Clark

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Posted 04 February 2016 - 01:38 PM

As noted, The Zone System is predominantly a Black and White process. The scene and resulting display image was visualized in terms of B&W materials, from negative to final print hanging on the wall.

 

Ansel Adams himself stated he never got an effect way to think of 'color' such that he would have the same control as he did with B&W... other have applied the Zone System to color, but the system is still described in terms of 'grey values'...

 

What is the core of the system is what is called 'previsualization', that is the photographer is at the point of taking a picture (or pressing the run button on a motion picture camera...), and because of the process will 'know' with in reasonable confidence, what the resulting image will be when displayed to the viewer.

 

There are other systems for doing that but the Zone System has had perhaps more success. One of the reasons for the success is that it is based on understanding the capabilities of the medium of capture (negative, but Adams also applied his system to Polaroid... even a consumer camera like the 70's vintage SX-70...), the medium of presentation, in the case of stills The Print.

 

The question you pose is really only the first step in the Zone System process... that step is 'how does the recording medium respond to light'... Film may have had the capability of recording detectable differences in light intensities up to '14 stops', or perhaps even more... until the silver 'crowbared' into less density, yielding 'black sun' effects...

 

However, in the print material, one was stuck with about 7 stops of range capability, so the goal was to find out how to expose, process, print and yield a print which was within that range.

 

In most formal Zone Systems classes that I had way back when, one would find the change in density of the negative by using a densitometer, and reading out the density changes produced by varying the ISO, or ASA as it was termed back in the olden days, or the f-stop of the lens. A series of negative was taken, tedious hours processing, more tedium reading the densities, etc...

 

Then there was printing, tedious hours printing, finding that density in the negative which yielded that 'hint' of difference between 'black' and 'less than black'... likewise for finding that 'hint of grey' just be fore 'pure white' in the print...

 

The spot meter was recommended because one could read out the relative values of 'shadow', and 'highlight' directly and so, once one had calibrated the process one could read out the meter for shadow, know that the exposure would be X, read out the highlight and know by process and printing the result would be as one desired.

 

Some of the Zone System would not 'work' for motion pictures, as in the case of stills, there was a variety of ways one could modify the development process, a variety of 'papers' to use which allowed one to compensate for different contrasts, etc.

 

But the main goal of 'previsualize' and know that the exposure and process will produce the desired results could be achieved... albeit with some resignation that one could not control everything to any level desired...

 

In the modern digital world the IRE waveform display can replace the 'densitometer' and so, one can use that to evaluate the capture medium characteristics... and far more easily... than using a densitometer. But that is not the end of the process... the next step is to know what the presentation characteristics are...

 

And here one has a plethora of options... most of which don't have 14-stops worth of display capability... perhaps for some display, one has only realistically 5 or 6... with more money... perhaps 8-9... and in some beatific future... 10+...

 

So back to your question... if your capture medium has 14 stops worth of range and your output display only has 7 steps... you have to chose some 'curve' which compresses the capture range into a 'pleasing' display range...

 

For most people who are not funded to support professional services... it means that they will need to learn some package sufficiently to get their desired results... Of the popular prosumer packages there's Adobe products, such as Premiere, from Blackmagic Designes there DaVinci Resolve, and of course Avid has had a long standing industry presence...

 

For those working on the cheap... Blackmagic does have a 'free' version of Resolve... but I subscribe to the Adobe Creative Cloud, and so I use both Premiere and Resolve for dealing with motion picture processing.

 

For stills I use Photoshop, and occasionally Lightroom... but mostly Photoshop...


Edited by John E Clark, 04 February 2016 - 01:41 PM.

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#6 Ben Brahem Ziryab

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Posted 04 February 2016 - 04:26 PM

Lighting is a different issue, you can control tonal range with lighting.  Once I tested a stock and knew the tonal range I got for the typical release format gamma (Rec.709 video, film print, whatever) then I'd know when it fell to black or burned out to white for that gamma (more limited than the negative's range).  So then when I was lighting, I'd know how dark to make a shadow versus how hot to make a highlight, with the knowledge that if I was doing digital color-correction, I'd have some room for manipulation.

 

But otherwise, your testing would tell you that, let's say, 4-stops under on your spot meter was near black but with some faint detail in the print, and maybe you've decided that the face should be 1-stop over in that scenario.

 
What I think I'll do is shoot a grey card on V3 to see what I am getting for each exposure increase and decreasing of one stop. Then draw out two charts; one with the tonal range of the negative and another with the Rec 709 tonal compression. These could be programmed into the Sekonic L758-Cine to create a "latitude" display, or I could simply mark them on a analogue spot meter.
 
As John Clark pointed out, the Zone System is designed for black and white film only, so I don't know if you can establish zones that represent various brightness levels for every color.
 
The idea is that I could use the system to communicate with the production designer on how dark I want a certain wall or table just by showing that person a "zone" that corresponds to a exposure value based on the tonal range of the film stock and release format.

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#7 David Mullen ASC

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Posted 04 February 2016 - 05:28 PM

To set your Rec.709 look, since there isn't a strict standard for gamma, after all, you can show a flat log image on a monitor, shoot an 11-step grey scale at your standard exposure rating so you can put the white patch at 90 to 100 IRE and your black patch at 0 to 5 IRE, which is typical for dailies colorists transferring negative.
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