the zone system

[perfectpixel]

Hi,
recently I checked out a book from the library on "the zone system for 35mm photography".
It basically had things divided into ten zones with zone I being absolute black and X pure white, I am sure most of you are more familiar with it.
From what I remember, it stated that all camera light meters are calibrated to expose at a zone V (18% gray card) and that the best exposure zone value for the average caucasian skin is zone VI.

My question is this: does that mean that if I have spot metering on the subject's face in Av mode, should I dial in +1 stop exposure adjustment?
Hope this makes sense.

[ryuwulf]

Yes cameras do meter at 18%grey. Every camera is different. Use a grey card by your subject to make a comparison. Some cameras are off by one stop. Ive seen a canon rebel 200 be off by 2 stops.

So to sum it up, bracket your shots and note the settings. One of the settings should be exactly or very close to the 18percent .

hope that helps

[Roger_Cavanagh]

You might find this of interest:

http://www.rogercavanagh.com/helpinfo/29_graycard.htm

Regards,

[stopbath]

Here is a good web based tutorial on the zone system for anyone interested in reading up on it.

http://www.cicada.com/pub/photo/zs/

[dmalek]

for accurate skin colors you can also use a lightmeter and measure light directly on the skin (if this is portrait that you do). then you get aperture and speed and use them in manual mode and you forget about the 18% grey issue.

i thought the zone system thing was a darkroom technique only. something like asking you to develop bands of prints with various paper exposure duration to get the greys you want in B&W photography only.

[gandini]

Just goes to show. Ansel Adams put forward the Zone system in his book The Negative, in the 3-book series of very technical books he wrote about the science, practice and art of photography. He and Minor White were responsible for turning his practice into the Zone System that has been used by many photographers, and mis-understood by many more. It is essentially a way of understanding the luminosity range in the original scene, as measured by a light meter, the luminosity ranges of the film and paper, and using them creatively, sometimes matching them, and sometimes intentionally mis-matching them. Since Adams was using film, developer and ultimately printing them on paper, he talked about "pre-visualizing" the final print when exposing and developing the negative.
Much of the Zone System methods apply to color photography since it contains a Luminosity element, yet the color really adds great complexity that is not there in black and white (pure luminosity.) There are books and tutorials aimed at applying the Zone System to color. Digital photography should add no more to the complexity other than learning the dynamic range of your camera's sensor (probably no more than 5 EV) and the same of the viewing medium you choose to display your photos with (LCD, CRT, paper.)

cheers,

[Jesper]

My question is this: does that mean that if I have spot metering on the subject's face in Av mode, should I dial in +1 stop exposure adjustment?

Yes. The aperture / shutter time combination that results from your camera meter is set so, that the place you've metered at will have the intensity of 18% grey in the photo.

So if you spot meter on something light, you need to use + exposure compensation, so that it will become lighter in the photo; if you meter on something dark, use - exposure compensation.

You can also use a standard 18% grey card to determine the correct exposure: meter on the grey card to find the correct exposure setting.

[hkelsey]

Ansel Adam's zone system matches film to paper and the film is a negative. In digital, we are working with a positive image. If you spotmeter a face and put it in zone 6 with a +1 exposure increase, is this not reversed, unless you flip the image to a negative in PS?

[stopbath]

I don't grasp your question fully, as I don't see a conflict using positives or the extra negative step with the zone system.

Zone 6 is one eve brighter than zone 5. Right?

In negatives, zone 6 will be darker by zone ev than zone 5 (due to more intense light). During printing this will block 1 ev more light than zone 5 will, producing an image one ev brighter than zone 5 (due to less intense light). For slides and digital zone 6 is one ev brighter than zone 5. No monkeying around.

[hkelsey]

I have always shot negative film so to me I spot meter on skin and place in zone 5 by changing shutter or f stop. With digital, I realize that the Ev adjustment does the same thing.