Zone system in practice

30th April 2015

Demonstrate your awareness of the principles of the Zone System and your ability to take accurate light readings by producing three photographs taken in relatively high dynamic range, i.e. contrasting light conditions. Make sure that your exposure choice renders as much detail as possible in the brightest and darkest areas of the photograph. 

Collate your work and any reflections in your learning log.

I studied the Zone system in Photography 1: Digital Photographic Practice. The most helpful book I found which enabled me to work out the zone system in landscape photography was Frye M (2009). I revisited the technique to see if I was still using it correctly.

Frye (2009 p42) explains how the zone system works in relation to digital imaging. "its easy to increase contrast, but difficult or impossible to decrease it. So if an image looks too flat, it's easy to add more punch later in software. But if the scene has too much contrast - if it exceeds the dynamic range of the camera - then part of the image will either become pure black or pure white."

If the contrast range is fixed, the zone system is still useful to set the exposure accurately. I use the spot meter built into my camera. The difference between colour photography and black and white is that light colours loose saturation beyond zone 6 and although it retains detail, the colour is pale. A dark colour becomes muddy below zone 4. Ansel Adams used the zone system for colour photography. Frye cites Adams "I have found that the Zone System is invaluable in colour photography, primarily in relation to exposure, but of course its application poses very subtle considerations". (Frye 2009 p42)

This image shows how the zone system can be compared with the histogram and if checking the histogram and the flashing screen, the photographer has an idea at the time of shooting the image whether it will be OK or whether there will be too much loss of detail in the shadow or highlights. Ideally pixels should be between zone 2 and zone 8. Anything which falls outside of these zones will register as pure black or be over-exposed.













This guide shows what subjects equate to each zone...

...and in colour.
















Image 1

f16 1/20 ISO100 28mm tripod polarising filter

My Raw image shows that there is a very small amount of blue shading at the water's edge and in one patch of grass which indicates a little loss of detail. To go one stop up would overexpose the sky. I used a polariser filter to retain the colour detail in the sky. I decided that this small amount of loss of detail was acceptable for this image.


























Image 2

The screen shot below the image shows the Raw file and histogram. I have tidied up the original image; cloning out the spot in the sky, cropping out a stray stick and warming the colour up a little making it reminiscent of the late afternoon sun. The original image was taken to give the best exposure and this is what Ansel Adams means by visualization. If I had exposed differently, there would have been under or over exposure. 

f13 1/80 ISO 100 24mm

Rather than use auto bracketing, I take what I think is right and then take a photo half a stop either side of the original exposure. I tend not to rely on the camera's suggestions because I have found the camera can get it wrong, especially when faced with scenes of more dark or more light. I was advised to leave the white balance on auto by a previous tutor and adjust accordingly. This practice seems to work for me.


















Image 3

In this image of a tree in the late afternoon, there is a lot of shadow detail. Looking at the raw image, I exposed correctly for the scene because there is still detail in the sky (clouds) and the shadows have detail too. This is an occasion where the camera insisted on shooting one stop above my settings which would have over exposed the image. By measuring the scene and deciding where to set the mid point, I was able to expose correctly.

f14 1/80 ISO200 35mm

Bibliography
Frye M (2009) In the footsteps of Ansel Adams and the Great Masters, Ilex press
http://photography.tutsplus.com/tutorials/understanding-using-ansel-adams-zone-system--photo-5607 accessed 30th April 2015