Jump to content

Understanding the on-set application of the Zone System


Recommended Posts

Beginner question. Looking for some clarification regarding the actual application of the Zone System on set.

 

Assuming we stick with the very general "convention" of fair skin being +1 stop, mediterranean as is, and dark skin -1 stop. Theoretically speaking, if my main goal was to expose for the talent's skin, would I simply measure the talent's skin and adjust accordingly to their skin tone (+1, 0, -1)? Of course, I would have to check in what zones the rest of the photographed set would fall into.

 

Any clarification would be greatly appreciated.

 

Alex

Link to comment
Share on other sites

I think you're slightly misunderstanding the Zone System.
The Zone System is just a guide to help create a more
aesthetically pleasing image through lighting and exposure.

Normally, you would find something in the frame that is at key,
which often time might be the face of the actor as you mentioned,
and you would overexpose and underexpose other areas of
the frame -- in a day interior you might blow out the windows,
which would then be the most overexposed portion.

You want to light the scene based on the latitude (aka dynamic range)

of the film camera and film stock (or digital system), the desired look of the film,
limitations of the location, time for set-ups, etc. For instance, you might not be
able to create a perfect 10 zone system in certain locations, it might not be
possible to sufficiently underexpose any area of the frame.

The Zone System is simply a beginners guide to understand how exposure
and lighting interact in photography. After a certain point, you don't even
think about it, you simply light a scene and instinctively add or take away
light to better serve the style of photography for that story.

If you'd like to see how cinematographers actually use the Zone System
I would recommend the book Reflections: 21 cinematographers at work.

http://store.ascmag.com/product-p/10701.htm

It's expensive but it's a really good book.

-mpb

Link to comment
Share on other sites

I'm a little confused by your question.
I wouldn't recommend thinking in terms of zones for exposure.
You might use a 18% grey card, which, when properly exposed,
would be exactly zone V. When you start talking about skin tones
and "reflectiveness" you're now talking about exposure, and I think
the the zone system is confusing you a bit. You should be thinking
more in terms of exposure.

Here's some good material that I think might help you:

 

http://www.cinematography.net/edited-pages/Philosophy%20of%20Exposure.html

 

http://www.chrischomyn.com/documents/book/05-understandingexposure.pdf



Link to comment
Share on other sites

  • Premium Member

Without controlling contrast in development as in the Zone System you can't really place more than one tone in a specific zone, the rest will fall where they will fall depending on the film stock. So you could place a face in Zone V or Zone VI if you want and meter to see where everything else might fall but the point of the Zone system was to manipulate contrast in development and printing so you can pre-visualize which zones the midtones, shadows, and highlights fall in for the print.

Link to comment
Share on other sites

Beginner question. Looking for some clarification regarding the actual application of the Zone System on set.

 

Assuming we stick with the very general "convention" of fair skin being +1 stop, mediterranean as is, and dark skin -1 stop. Theoretically speaking, if my main goal was to expose for the talent's skin, would I simply measure the talent's skin and adjust accordingly to their skin tone (+1, 0, -1)? Of course, I would have to check in what zones the rest of the photographed set would fall into.

 

Any clarification would be greatly appreciated.

 

Alex

 

 

The Zone System in its essence is a method to visualize the final 'print', since the system was for still photography... when viewing the original scene.

 

How one does this is to know how the Film negative responded to the scene light (as in levels and contrast), and how in the print process those scene values were represented.

 

In terms of motion pictures, the system would allow the cinematographer to previsualize the final 'projection' image, given the Film negative materials, processing, and printing the projection print.

 

How was this done... by testing relative to the 'standard' 18% grey card, knowing that Film negative material had a certain base exposure, and the 18% card resulted in a specific density in the negative, and resulted in a certain print density when printed on paper...

 

Again Ansel Adams was still photography oriented... and further... he was specifically B&W oriented... he stated he never came up with a 'zone system' for color that met his satisfaction...

 

All that said...

 

To apply the concepts of the Zone System to any Digital Film camera, recorded image, and presented image, one needs to know what the camera is capable of recording in terms of light levels to the digital camera values, and the output presentation method, wither projected in a 'dark' theater or seen on a 'mobile' device with high ambient light...

 

Ok... maybe one only thinks about a dark theater... but in any case, when standing at the scene to take the image, one does need to have the image of the final presentation in mind.

 

In any case, one needs to find what how the camera responds to light intensity levels, and what adjustments either in camera or in post processing are available to achieve the desired presentation image.

 

Since I don't have a good 'step wedge' which would be the simplest method to obtain the camera's 'response curve', I tend to use a grey card, and a chart that has color patches and a very limited step wedge.

 

I also use the IRE waveform display in my NLE of choice to observe the grey card levels, and the step wedge curve.

 

For my Blackmagic Design Pocket Cinema Camera, when shooting 'RAW' mode, I use 38% IRE value for the 'grey' card level, when the media is displayed using the Blackmagic 'log' (aka Film) mode representation.

 

For my GH-1 which is really uses a Rec. 709 representation, I set the 18% grey card to be 50% IRE. (Some people use something less than that, more like 40-45...).

 

I use the manufacturer's 'native' ISO value, in the case of the Blackmagic Pocket, that would be ISO 800. I then find a 'fudge' factor adjustment to the ISO value, which achieves the desire 38% IRE for the grey card.

 

One that is determined, then one can check that 'caucasian' skin is +1 stop, etc. or any other reference, like "alabaster" stone may be +2-2.5 stops... For still photography it was 'white' paint with 'aging cracks'... that was the 'test standard' for textured detail in the whites, and the cracks being the 'contrast' black points... don't know if that would work for 'moving pictures'...

 

Another test I do these days with the color chart and simple step wedge is I expose something like +2 stops, then 'print down' via the NLE color/levels adjustment, to see how whacked the image is, with 'over exposure'... same for -2 stops and boosting levels. One can also use the NLE adjustments to see what happens with 'increasing contrast' and banding due to limited bit depth and the like.

 

One of these days I may make a video tutorial on this topic... but there are others already out there...

 

But back to the fundamental message... previsualize, then know how the process will achieve that image.

Link to comment
Share on other sites

  • 2 months later...

Without controlling contrast in development as in the Zone System you can't really place more than one tone in a specific zone, the rest will fall where they will fall depending on the film stock. So you could place a face in Zone V or Zone VI if you want and meter to see where everything else might fall but the point of the Zone system was to manipulate contrast in development and printing so you can pre-visualize which zones the midtones, shadows, and highlights fall in for the print.

 

David,

 

Suppose I put 18% grey card in the a place (where i wanted to place my subject) and measure the light. Say, i got an exposure f/5.6.

If i expose the face of my subject for 5.6 would it be a correct exposure or under exposure? Would it also depend on the skin tone of the subject?

Link to comment
Share on other sites

If your measured exposure from a grey card says f5.6, and you expose at f5.6, then, yes, you have a 'correct' exposure. That doesn't mean that your exposure will result in an image that you like. That is down to artistic interpretation.

 

Skin tone will have no bearing on your exposure if you are measuring from a grey card, just as incident meter readings are independent of the actual subject.

Link to comment
Share on other sites

If your measured exposure from a grey card says f5.6, and you expose at f5.6, then, yes, you have a 'correct' exposure. That doesn't mean that your exposure will result in an image that you like. That is down to artistic interpretation.

 

Skin tone will have no bearing on your exposure if you are measuring from a grey card, just as incident meter readings are independent of the actual subject.

 

>Skin tone will have no bearing on your exposure if you are measuring from a grey card, just as incident meter readings are independent of the actual subject.

 

Would a 'white colored' skin looks grey if i expose as said earlier?

Link to comment
Share on other sites

  • Premium Member

If you put a grey card next to a paler face and spot-metered the grey card and exposed for that reading, then the paler face would render as being paler.

 

If you spot-metered the pale face instead and exposed for that reading, then the pale face would look darker, as if it were 18% grey in brightness. The spot-meter is assuming what you are pointing it at is 18% grey in terms of the reading you get.

 

So you can spot-meter a pale face and then decide how many stops brighter it should look over that reading -- you might decide, for example, that you want the face to look one-stop brighter than 18% grey to feel correct, so you'd open up one-stop over the spot metering reading you got.

Link to comment
Share on other sites

If you put a grey card next to a paler face and spot-metered the grey card and exposed for that reading, then the paler face would render as being paler.

 

If you spot-metered the pale face instead and exposed for that reading, then the pale face would look darker, as if it were 18% grey in brightness. The spot-meter is assuming what you are pointing it at is 18% grey in terms of the reading you get.

 

So you can spot-meter a pale face and then decide how many stops brighter it should look over that reading -- you might decide, for example, that you want the face to look one-stop brighter than 18% grey to feel correct, so you'd open up one-stop over the spot metering reading you got.

 

>If you put a grey card next to a paler face and spot-metered the grey card and exposed for that reading, then the paler face would render as being paler.

 

In a scene where light falls with different light intensities, where would i place the grey card to measure the exposure? I understand that exposure reading grey card falls in zone V.

Edited by Mathew Collins
Link to comment
Share on other sites

  • Premium Member

A spot meter is a reflected meter, it just measures a smaller area.

 

An incident meter measures the amount of light falling onto the dome. If you pointed a spot meter at a grey card, you should get the same reading as you would if you measured the light falling on the grey card with an incident meter.

 

But switch the object from a grey card to a pale face, then the incident meter reading would be the same as before but the spot meter reading would be different because it would be assuming that the pale face was 18% grey.

  • Like 1
Link to comment
Share on other sites

  • Premium Member

I think what you're asking is where physically-- and the answer to that would be in the light in the area where what you're interested in would be happening.

 

If you had a room with large beam of light coming in, and you wanted a "proper" academic exposure of a something based off of a grey card in the shadow, you'd put it in the shadow. If you wanted a proper exposure for things within the light, you'd put the grey card in the light.

 

Of course, this won't make a good looking image-- necessarily, it'll make an image which in that area is properly exposed so as to render a grey card grey-- which is great-- and other things would fall where they naturally would fall-- until they are out of range of the recording medium, whatever that may be.

 

Instead, it would be better to think like this, I think, in terms of the "zone system."

 

you meter the scene with your incident meter-- in the area in which you will place your actor-- let's say it's in the shadows-- and you get some reading. Next you use your incident reading in the bright lighted area-- and you see, maybe it's +5 stops! Well, obviously, 5 stops over would be white-- pure white-- bright!

Maybe that's not that you want, maybe you want it not super white-- but not so white, and you decide, maybe 3 stops over would be better. So you're options then are to bring down the light through the windows by 2 stops, or bring up the shadow light by 2 stops by lighting.

That's kinda how we use it, in a way; to know, well, this many stops over this level of exposure is going to be roughly this, or under will be roughly this (white with some texture, black with some information-- honestly, this terms are nebulous in a lot of ways), and through experience you know in this situation, I wan't my blacks AAAAALLLLMMOOOST but not quite "black," and I want the brightest area of my frame just a stop above middle grey.

Link to comment
Share on other sites

As told previously, the Zone system was primarily developed taking final printing into consideration. Ansel Adams was THE Editor (with capital E), par excellence (albeit not literally since he had his private printer), in the photography world. One of his most famous quotes were: "You don't take a photograph, you make it", and he was talking about the enormous post production process involved on every of his photos after he'd press the button, and that was where the Zone System resided.

 

I advise you to make a simple but effective exercise for you to better understand it's basics:

 

1. Grab a still DSLR.

2. Put it in monochrome mode (it's easier since you're going to see the luminance results better and put the chrominance details aside).

3. Ask 2 of your friends to bear a minute with you. Ask one to dress a white shirt and the other to wear a black one. Put the 2 under the same light.

4. Put the camera in AUTO mode without flash. Choose your ISO but let it determine the aperture and shutter speed automatically.

5. Fill the picture with the white shirt and shoot.

6. Now fill the picture with the black shirt and shoot.

 

You will find that both will be represented in a medium grey (for what the reflected camera meter is calibrated). That is your Zone V. Now:

 

7. If you want your friend's white shirt to appear white with some detail, you will have to expose for more 4 stops than the automatic measure told you (Zone 9).

8. If you want your friend's black shirt to appear black with some detail, you will have to expose for less 3 stops than the automatic measure told you (Zone 2).

 

Bear in mind that - as also told by some members previously - Zone 9 and 2 will vary and will depend on your system (digital), or your stock (film). An Alexa with a 15 Stop DR will put it's black retaining detail exposing for far less than 3 stops for instance.

 

Also bear in mind that digital and film will be exposed under the known rule that one is exposed for highlight and the other for shadows. Both will respond differently at those two extremes so if you want to put the Ansel Adams theory to work you will need to know your medium and/or your camera as the back of your hand, so that you can expose properly taking the post production into account.

 

Relating all this to film, make a google search on how printer lights work with a film print. It's perhaps your next step to understand the validity of such thinking when you are exposing your stock. When you talk digital, all the camera and lens tests that any decent DP conducts prior to any shooting will relate not only with the best tools to use within the storytelling but also to know it's limits and to account for the DI and post production process. That is to say, take into account the finished process before it even begins, and that is what the Zone System is all about.

Edited by Alexandre de Tolan
Link to comment
Share on other sites

  • Premium Member

The Zone System is also based on manipulating gamma (contrast) in development and in the printing papers used. If you can't manipulate contrast, you can only really pick one Zone to place an area at. Unless you can expand or contract the contrast, you can't, let's say, pick one Zone for the face but another Zone for the white shirt if they don't naturally fall into that range. And while one can play with gamma in digital color-correction, you generally don't go too far with that, particularly between shots within a sequence, there is normally some sort of general consistency to the feeling of contrast unless you are going for a stylized effect where one scene is high-con and another scene is low-con.

Link to comment
Share on other sites

3. Ask 2 of your friends to bear a minute with you. Ask one to dress a white shirt and the other to wear a black one. Put the 2 under the same light.

 

Since I have no friends... I use black velvet and a white 'embroidered' cloth. The two will allow one to check textured shadow and textured white, along with a color chart, with a limited grey step wedge...

Edited by John E Clark
Link to comment
Share on other sites

 

Since I have no friends... I use black velvet and a white 'embroidered' cloth. The two will allow one to check textured shadow and textured white, along with a color chart, with a limited grey step wedge...

 

Shame on you :) Everybody should have a friend ;) The problem with color charts is that they don't drink bear :)

Edited by Alexandre de Tolan
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...