Taking Creative Control
Besides using exposure compensation to get back to what you determine as correct exposure, you could also employ exposure compensation to creatively control the exposure of your images.
Depending on your intended final image, you may not want to keep what the camera is telling you as the suggested correct exposure. Previsualization is the key.
What Is Previsualization in Photography?
Previsualization is exactly what it sounds like. You have an idea of what you are aiming for and what you want the image to look like. You can visualize ahead of time and then work your methods and settings in order to achieve that intended result.
Some of the old masters of film photography used this method to great advantage. We might especially observe the black and white imagery of Ansel Adams.
As a photographer, you probably are at least somewhat familiar with the black and white scenic landscapes of Ansel Adams. If not, take some time to look him up. If nothing else, you’ll enjoy his work. It’s his method that we really want to examine. He devised a system of previsualization called the Zone System.
You can learn about the Zone System in three books authored by Ansel Adams: The Camera, The Negative, The Print. These are well worth reading for an insightful view of the photographic process that is still relevant for digital imaging.
In simplest terms, Adams divided deep black and bright white and everything in between into 11 different discrete values or zones. Zone 0 is deep black, Zone V (5) is middle gray (18 percent gray), Zone X (10) is pure white. By the way, these light values are legitimate in color imaging, too.
As you can readily determine right away, Zone 5, middle gray, is what your camera meter is trying to capture most of the time.
What Ansel Adams and others would do is select an element of the scene and say to themselves that they want that to end up in the final image at a particular Zone System value. Then, they’d do all their exposing and processing to make that happen. In addition to individual parts of the scene and their exposure values, you could also choose several different subject elements and a range of Zone System values you want them to encompass.
You can still do this in digital imaging. In fact, you actually have more control now because of how much more exposure detail your camera sensors and computer processing can hold and reveal.
For your creative digital imaging, you could use the Zone System to take the scene in front of you, pick what details you want to emphasize in one way or another, determine ahead of time (previsualize) what zone those parts of the scene would look best as, and then use your exposure compensation dial to shift everything up or down one or two zones.
A similar thought applies if you wish to create high key or low key photos. An easy way to achieve high key is to dial up the exposure. For low key, dial it down towards the minus side. Of course, there is much more that can be done for high or low key, but exposure compensation is an easy start to those effects.
Exposure Compensation Tips
If you’re shooting digital, you have an option that didn’t exist in film cameras. You can review your images right after taking the picture. Some people call that “chimping.” Chimping can be distracting to the shooting experience when you overdo it. On the other hand, chimping, or reviewing images as they are shot, is good practice in challenging lighting conditions.
Are you old enough to remember Polaroid cameras? When the developed image showed, you could see if it was correctly exposed. If not, you moved the Brighten/Darken dial one way or the other and reshot. The same idea works for on-camera image review and using exposure compensation.
Another helpful practice is having your camera viewscreen image review also show you the histogram. The histogram exposure value display is one of the more useful tools to have come to cameras in the change from film to digital imaging. Once you know what the histogram is telling you, you can use it to great advantage in all of your digital photography.
What changes in each automatic mode when you change the exposure compensation? It may vary slightly from brand to brand, but generally, it works the same way as the exposure modes.
If you are in shutter priority, the exposure compensation changes the f-stop. In aperture priority it changes the shutter speed. For programmed mode, it changes both shutter and aperture.
One important thing to remember is that with most cameras, if you are in what I call the Green Dot Auto Mode, exposure compensation is disabled. Green Dot Auto Mode takes full control of all settings. The only things it allows you to change is where you point it, how much zoom, and when to click. Useful for quick snapshots, but not the default mode for serious shooting.
Related Exposure Method – Bracketing
Closely related to exposure compensation is another method of exposure control: exposure bracketing. This technique takes extra images at different exposure values. You can set many current cameras to bracket exposures in all auto modes (except Green Dot) and also in Manual (M) mode.
Typically, you can set the camera to fire off three, five, or up to nine shots, changing exposure up and down from one to three stops, sometimes with incremental values allowed.
For instance, if the metered correct exposure for the scene at ISO 400 is 1/125th at f/8.0, the camera could expose extra frames at 1/60th and f/5.6 and 1/250th and f/11.0 if you were in P mode and selected three frames bracketed at +- 2-stops.
Likely, one of the bracketed shots will be a usable image file for what you have previsualized as your final photograph. Obviously, you can adjust your bracketing settings and what mode you’re in depending on your specific camera.
Bracketing is also related to another advanced new method made possible by digital imaging: HDR.
High Dynamic Range photography, or HDR, is a method of either evening out or enhancing the exposure value or range of values within a scene.