Week 5: Zone System

06.09.2013
Wan Mohd Danial (Danny) (0316570),
Introduction2Photography
Exercise 3.1 & 3.2 : Zone System & Ansel Adams Shot

Lecture:

The Zone System

The first thing that appeared on the slide is, you need to know that the exposure meter on your camera is dumb, REALLY DUMB. They assume that all scenes have the same average tonal value (usually middle grey at zone 5 in the chart.

If a scene is different, for example a snow scene, it will be exposed incorrectly. It will come out middle grey which is underexposed for something that should look white. If you follow the meter's reading, every scene will have the same average middle grey density. You'll get tons of bad exposures.

Ansel Adams developed the Zone system. His technique was to carefully study a scene, visualise the final print, then determine the correspondence between portions of the scene and tones in the print. He would then use meter, overexpose or underexpose the image to get the correct exposure for the image.

The goal of the simplified Zone system is to expose film/ccd for optimum image quality to make sure all the critical information is present.

Tones in scenes and prints are divided into nine zones, numbered 1 through 9 from dark to light.

Zone 5 is, by definition, subjective middle gray.In a scene, in the field, each zone represents a doubling or halving of the luminance which is the light reflected from the subject or equivalently, a difference of one f-stop.

The key to the Zone System is to visualise how you want the areas of the scene to look in the final image. The Zone System is all about selecting an area of the scene, meter it, adjust the exposure by the difference between the zone you want in the final image and zone 5 which is the middle grey zone.

Exercise:

Exercise 3.1

We have to choose 3 different subject matters of varying tones. One has to have different shades of white, the other has to have varying shades of grey, and another one that has varying shades within a dark area.

Dark Tone:

SS 1/2  F8.0  ISO 400
Correct Exposure according to meter

SS 1/10  F8.0  ISO 400
Correct exposure according to me

 Middle Tone:

SS 1/25  F13  ISO 400
Correct exposure according to the light meter

SS 1/50  F13  ISO 400
Correct exposure according to me

Light tone:

SS 1/3  F11  ISO 400
Correct exposure according to the light meter

SS 1"6  F11  ISO 400
Correct exposure according to me

Feedback 3.1

This exercise is done correctly.

Reflections 3.1

The top picture of each tone is taken with the correct exposure according to the meter on the camera which is usually in zone 5. The picture below it is taken using the exposure I think is the correct one which is at zone 3 for the dark tone photo, zone 4 for the middle tone photo, and zone 7 for the light tone photo. This shows that the light meter measures at an average tonal value which at certain times is not the correct exposure for a subject. For example, the picture of the folder which is taken using the correct exposure looks greyish even though the folder is supposed to look white making it look underexposed.

Exercise 3.2

We have to take a picture according to the Ansel Adams shot according to the right exposure of the object according to us but not according to the camera. We also had to sketch out a plan to assign the zones across varying areas of the image we want to take according to the zone system chart.

Ansel Adams Sketch

SS 1/80  F13  ISO 100

Feedback 3.2

In my first attempt at recreating the Ansel Adams shot, the dark areas in the photograph came out too dark that it's not visible.

Reflections 3.2

From the picture taken above, it is shown that using the zone system can help get a picture with good details and the correct exposure that the subject matter really has.