The “Modified” Zone System Approach To Exposure
by William Lulow
Those of you who are truly students of photography have undoubtedly heard of the ZONE SYSTEM of exposure as put forth by Ansel Adams and Edward Weston, among others. It was a way of trying to make exposure more scientific in Black&White photography. Each tone, from pure white to jet black was assigned a zone (I through VII) and the idea was to expose a negative so that each of the seven zones could be reproduced in the print. Just about all the books I have ever read on black & white print quality have made reference to the importance of representing all the tones that were possible to show in a print. That’s what made the print a “good” print. If there was no detail in the shadows or the print had “blocked” highlights (meaning the negative was completely black) then the print was rejected.
Now, Adams was truly an artist, but he was also a scientist who understood perfectly, the techniques of exposure and development in black & white photography. His ideas about zones were emulated by photographers the world over. Of course, when he was working his magic back in the 1940s and early 1950s, color photography was just gaining acceptance with Kodak’s “Kodachrome” film. Color film was actually invented in the 1930s but didn’t achieve worldwide use until the late 1950s.
My point here is that the technique Adams and Weston perfected can still be used today in digital photography. The beauty of the idea is that Adams would decide what kind of image he wanted to make and then expose and develop his film accordingly. Over the years, I have modified the Zone System to suit my needs. But the one thing my notions of exposure had in common with Adams’ was that I decided before taking the picture, how I wanted the most important details to be reproduced. In other words, I would look at a scene and decide what shadow details I wanted to preserve and then expose accordingly, letting the remaining “zones” fall as they may. Now Adams would be able to shoot and develop his negatives to expand the zones if he wished. These days, this can be accomplished digitally with software applied to the captured images. You can adjust contrast, hue, saturation, lightness, darkness, etc., with appropriate software. However, this does not negate the original idea of THINKING about what you want to show in the scene whether in B&W or in color.
That was the beauty of what Adams was doing. He thought about it. Most people who want to record scenes these days don’t really think about what they are photographing. They just point the camera and shoot. Software can correct most technical mistakes but cannot correct the mistake of NOT THINKING!
So, my “modified zone system” approach is simply to decide where I want to show detail and expose accordingly, letting the other “zones” fall as they may. I do this by setting my camera’s metering system to SPOT METER, then aiming at the spot where I want to show the most detail. I make a series of exposures until I’m satisfied that I’ve covered the tonal range of the scene with the idea that I’m going to adjust everything in post production.
This scene is a perfect example of my modified zone system in action. I decided that the scene would look better in Black & White than in color, so I shot it in original Black & White. This is not a conversion. I then figured I needed to show the texture in the wall as well as the brick walkway, so I basically set my exposure off the spot metering of the brick wall, then adjusted the exposure down by about ½ f/stop to hold detail in the highlights as well. This shot actually required very little adjustment in post production. I “saw” the shot in my mind’s eye and was able to reproduce it fairly faithfully within the confines of the digital process.
Now, I’m intrigued with some photographers’ interest in shooting in RAW format. This does preserve all of the information gathered by the camera’s sensor, that’s true. However, RAW format images cannot be used for photo reproduction. They must be converted to JPEG images before they can be sent, uploaded, downloaded or posted to a website. One reason is that the RAW format’s images are just too large. So, I argue, why not be extra careful about how you expose your images in the first place? If you use a light meter to determine various exposure ranges in a scene and expose your images accordingly to render the most detail, why shouldn’t you capture them as original JPEGS? I have been shooting images this way for various magazines, advertisements, corporate portraits and brochures for years now, with superior results. I understand that there are many people out there who like to have 100% of their digital information available to them for editing later in post-production. However, if you have a busy schedule, like many of us, spending hours editing RAW files may not be the best idea.
The Zone System can still be used to get the most from almost any tonal range, and it can be applied to shooting in color as well. The trick is to think about what you are shooting, who you are shooting for and exactly what you wish to show. So, if you have plenty of time and you want to adjust your RAW images after you shoot them, fine. My problem with this approach is that it often relies too much on the software to correct things rather than get it right the first time in the camera. It tends to diminish the importance of the thought process. If you can use the “Modified Zone System” to help you decide exactly what kind of image you wish to make, then it is a worthwhile tool.
