Sometimes this is true. If it isn't, manufacturers like Kodak provide 18% grey cards to meter in the same light as the scene to correct this. A meter will always try to turn what it sees into zone V grey regardless of whether it is black, white, or any grey in between. If it reads black for instance, zone 0 on our scale, it would indicate five stops over exposure to turn it into zone V grey. The Loch Arklett scene happens to average out about zone VI, so the meter's indicated average exposure would have been one stop over. But average would not be good enough. The mean zone with average reading is always V whether the range of subject brightness is the film-makers' assumed norm of five where detail is required, or the actual nine in this picture. This means that if I had exposed as indicated by an averaging meter (including an incident meter, or any meter pointed at a standard grey card in this scene), then developed as recommended by the film maker, I would have a negative where the bottom two stops of shadow tone value would drop below the dark grey that would reveal detail into near or full black, while the top two stops of highlight tone value would be pushed over the lightest grey into paper base white. So the print would have solid black shadows and stark white highlights where the viewer's brain knows there shouldn't be. In other words, the print would appear harsh and contrasty.

In fact, zone I reproduces as a print value so little different from black that were there not an actual maximum black next to it for comparison the eye could not discern the difference. At zone II, the print value grey is significantly different from black, but not enough to be able to define anything but a hint of detail in the shadows. It takes zone III before full shadow detail begins to show in the print. At the other end of the scale, zone VII is the last in which full highlight detail can be shown in the print. Zone VIII shows a very light grey with a hint of detail, and zone IX the slightest trace of off-white grey, indistinguishable from white unless pure white is placed next to it.

In this picture, being able to visualise the print value grey of each zone through practice, I decided to place the deep shadows of the near bank on zone II. This meant I took a spot reading of them, then decreased the indicated exposure by three stops (remember, the meter always indicates the exposure for zone V = three stops more than zone II). This gave me an exposure of 1 second at my desired f/16. The average reading would have been two stops less at 1/4 second. However, having now placed the shadows on zone II, the highlights unavoidably fell nine stops higher at zone XI (remember the nine stop brightness range between light values 8 and 17), which would mean that the highlights would print as paper base white. I decided that I wanted the lightest sky tones to print as zone IX, just off-white. So I knew that I would have to compress the tones in some way by two zones to do this.

Fortunately, reducing developing time from the indicated normal does compress the zone range in the negative, but, usefully, not equally across the range. Reduced development has little effect on the shadow areas of the negative (remember they are the clearer parts of a negative with little exposed silver to develop), but a proportionately greater effect in restricting the density of the highlights in the negative so that they print slightly darker in the print.

Thus by cutting back negative development in Perceptol 1:3 at 20'C from my normal 14 minutes to 8 minutes, I reduced zone XI to zone IX. (The control of development times or this purpose is discussed in more detail below.) The benefit of taking such care with the exposure and development was that the negative printed 'straight' on to Agfa Record Rapid normal grade paper with no burning-in necessary, achieving the pictorial effect I had visualised at the time. Some slight dodging is needed on the left of the sky to even-up the grey because the sun was just out of the frame to the right. Subsequent selenium toning intensified and deepened the shadow areas and I decided, on reflection, to burn them in just a little to give a strong base to the print. So they are now about zone I - or actually print value 1.

It's easy to take detail away and deepen print tone values in this way, but impossible to put detail in and lighten values if it isn't there in the negative. That's like turning up the volume on tape recorder playback if the sound wasn't recorded on the tape in the first place. So subtle control of exposure and processing like this isn't just an irritating technical fiddle. The picture could not have been made how I wanted it without these controls, and the negative produced was flexible in allowing different print interpretations.

The two complementary aspects of the zone system are determining the correct speed of the film itself and controlling development. How to do this is shown on other pages on this site. Or if you want a short cut method, look at the Unzone System pages.