Photographers can make their images more than average with correct exposure. Most digital camera light meters base their exposure settings on the amount of light reflected from a gray card and this represents the amount of light reflected by a theoretical average scene. In real life, photographers seek subjects a bit more interesting than a gray card.
What is the Correct Exposure
This is when the tones and brightness of the image correspond to the photographer’s impression of the scene or subject. This is part of the creative aspect of photography where the photographer’s object is to capture their impression of a scene rather than a mechanical reproduction where their only contribution is point the camera and press the shutter button
If darker colors are overexposed, they lose vibrancy appearing washed out with less impact. Conversely, if light scenes are underexposed they appear dull and grayish, once again losing their impact and crispness. This is a problem when light or dark areas are larger than the area the camera’s light meter designers predicted. Photographers need to adjust the camera’s exposure settings so the exposure of the most critical area of a scene matches their visualization of the scene.
Camera designers recognize that their metering systems are only a guide and many cameras are equipped with a range of controls so photographers can control the exposure settings to get what they consider is the correct exposure.
In-Camera Exposure Options:
- Metering modes: These alter the area of the image used for the camera’s Through The Lens (TTL) exposure meter reading. This is useful when there is mixture of dark and light areas, the photographer can choose which area to use for the exposure setting.
- Exposure Compensation: This allows some control over exposure while using automatic exposure modes. If the prevailing lighting conditions causes all shots to be slightly over exposed then photographer s can tell the camera to adjust the initial meter reading down by fixed amount. This is usually in half or one third of a stop steps.
- Histogram and Expose to the Right: The camera’s histogram display shows the number of pixels at each light level in the range from black right through to white. A common practice is to take test shots and use the histogram to ensure that the light areas, shown on the right of the histogram, are not overexposed. A high bar in the extreme right indicates the image is probably overexposed. Overexposed details in light areas are harder to recover than the dark shadows so the practice is to concentrate on the right of the histogram and avoid blown highlights.
PRO Tips: set the exposure compensation to under expose for a half to a third of a stop when using for semi automatic modes such as Aperture Priority or Shutter Speed Priority.
If you must shot JPEGs adjust the in-camera processing settings back of one step in the contrast and sharpening settings etc as it is usually easier to add more in post processing JPEG, but harder to reverse the damage done by over processing by the camera.
Leave Room for Exposure Adjustment in Processing
The key to a good exposure is one that allows room for final adjustment, too dark or light and you lose the fine color tones in the shadows or the highlights. Use your favorite RAW converter software such as Adobe Camera RAW (in combination with Photoshop) or Bibble 5 make very precise exposure adjustments.
The sample photo is an old one taken with the exposure suggested by the camera’s light meter. The meter tried to make the exposure conform to the average, making the snow gray rather than white and the result is underexposure. . In the second version using Bibble 5’s levels and curves tools, the image has more of the crisp whiteness of fresh snow. Some of the detail in the dark spots is lost and they are slightly noisy. Another half to one stop extra exposure would reduce these problems.