Photography is a great creative tool that allows us to express ourselves. Just as everything the whole idea can be daunting if not understood clearly. One of those very intimidating concept is the Zone System.
The Zone System was a technique formulated by Ansel Adams and Fred Archer in 1930. It was a standard technique put together to ensure a correct exposure is achieved each time a scene is captured and under every circumstance and even in the most complicated lighting situation.
What is the Zone System itself?
The Zone System divides a scene into 10 tonal scale, 0 to 10 to be precise. 0 begin pure black and 10 being pure white. Every tonal zone is assigned a number on the scale and every zone differs by 1 stop. The breakdown of the zone system is a follow:
- Zone 0: Pure black, no detail. This is would be the edge of a negative film.
- Zone I: Near pure black with slight tonality, but no detail.
- Zone II: This is the first Zone where detail starts to show; the darkest part of the image where detail is recorded.
- Zone III: Average dark materials.
- Zone IV: Landscape shadows, dark foliage.
- Zone V: Middle -gray, that’s what our light meter are sets to
- Zone VI: Average Caucasian skin tone.
- Zone VII: Very light skin; shadows in snow.
- Zone VIII: Lightest tone with texture.
- Zone IX: Slight tone without texture, (e.g., glaring snow).
- Zone X: Pure white with no detail. This would be light sources, or reflections of light sources.
The zone system are numbered by Roman numerals. Here is a diagram of the Zone system.
Do bare in mind that the Zone System was developed in an era where film was being used so the use of the system has slightly changed. For us digital photographers, we only to be concerned with the zones III to VII which means that the darkest part of the image falls into Zone III and the brightest part in zone Zone VII. This renders making anything that falls below Zone III under-exposed with no details while any thing brighter than Zone VII over-exposed.
Although that is this the rule followed by many, it is not something that I personally follow. I tend to work on my images following the all zones as I find that it allows for a better tonal ranges within my black and white images.
If you point your camera at an area with average reflectance and obtain the correct meter readings (a zero on the light meter), that area would be rendered as average. If you open up your lens or slow down your shutter speed by one stop, that area will become over-exposed by one stop. If you close down your lens or increase your shutter speed by one stop, that area will become under-exposed by one stop.
We know that the average tone is naturally placed into zone V. If you over-expose it by one stop, you’ll be placing it in zone VI (zone 6), causing it to render brighter than it actually is. If you underexpose it by one stop, you’ll be placing it in zone IV (zone 4) causing it to render darker than it actually is. Colours can also be placed within the Zone System.
As seen in the above image, average colours would appear on the final photo the same way they look if placed in the system correctly.render correctly when put in an average zone which is zone V. Those tones include green grass or tree leaves, red flowers, clear blue skies, 18% grey card etc….
Colour tones that are a bit brighter than the average (than seen in the image above), should be placed into zone VI. These colours are more like pastels, or faded average colours. Those tones include pure yellow, bright-pinkish red, baby blue, baby pink etc…
Colour tones that are brighter than that should be placed into zone VII. These include white snow, white clouds, fog, smoke, mist, bright sand, etc… This means capturing them by overcompensating the exposure by precisely 2 stop.
Colour tones slightly darker than average should be placed into zone IV. Those include tree trunks, dark blue skies, and this means usually underexposing by 1 stop.
Colour tones that are darker than that should generally be placed into zone III. Those tones include black puppies, black shoes, extreme shadows, coal, and in this instance underexposing by 2 stop.
In digital photography, a generally correct exposure of an average scene is that is exposed for the mid-tones, with no blown out highlights, emphasis on blown out highlights because, highlight clipped photo details are more troublesome than shadow clipped photo details.
So if the dynamic range of a scene is greater than one to be captured with only one shot, you have the choice to sacrifice either the highlights or the shadows of a photograph. And unless the jeopardised highlight area is really small then I wouldn’t sacrifice the highlights as they really difficult if sometimes impossible to recover. My take is to should always protect the highlights. Loss of shadow details tends to be more acceptable and sometimes even intentional for specific effects.
So to correctly expose an average scene, it is recommended to spot an average colour or tone to meter from. Adjust your camera settings till you get the light meter’s hash mark on zero for that colour, make sure you’re not over exposing your highlights and capture your image.
Scenes with high dynamic ranges
With high dynamic range scenes where there’s a huge difference between the brightest and darkest tones, it can be challenging even impossible to capture and retain all the contrast with just one image. In these instances, I personally tend to capture multiple images and then and then blend in post processing. Under these conditions, Neutral Density filters can also be of help. The aim in this situation will also be to protect the highlights.
The question that may be posed here is whether the zone system still applies to any of us especially since most of us uses a digital camera. From my point of view it does. By acquiring the understanding of the Zone system, I gained the ability to better understand how to meter a every scene and what works for my particular work especially the images that I aiming to create. I meter my scene for what works for me.
Photography & Vision 