For many, stepping out from behind their cameraphone and shooting with a DSLR, can be a big deal. Make no mistake, cameraphones are amazing, for what they are, but for us, there is nothing to match working with a DSLR and getting immersed in the process of attaining the best exposure of your subject. If you love to shoot landscapes, but often find that the exposures never seem to give the results you expect, don’t worry.
Bright, full range
In evaluative metering mode, on a bright sunny day, you may find that the image captured is fairly accurate in its representation of the scene, since there is a full spread of tones from lightest to darkest. The histogram should show an even spread throughout the midtone range with perhaps some small spikes at the highlights and shadows end. Depending on your creative approach, you may want to dial in a small amount of positive, or negative, exposure compensation.
A darker, low-key scene, such as an evening shot near dusk, will be metered in a different way. When a camera’s meter averages a scene, it assumes that the average of all the tones will be equivalent to an 18% grey reflectance value. Since a darker scene, by its very nature, is darker than that, the camera will overexpose the scene to achieve that 18% value. You will need to dial in about -1 or -2 stops of negative exposure compensation to get the exposure back down to an acceptable level. Your histogram should show a greater distribution of tones in the shadow areas on the left of the histogram.
A high-key scene is bright with very little in terms of shadow areas. Winter scenes or bright beach environments are good examples of this. Whereas a dark scene is metered for 18% and overexposed, it stands to reason that very bright scenes will be underexposed, since the camera’s meter is now trying to darken the overly bright scene to get it down to 18% reflectance. This can make images look dark and muddy. In this case, you will need to dial in anywhere between 1-3 stops of positive exposure compensation, in order to return the image to full brightness again. Your camera should now show a high distribution of tones in the highlight areas on the right of your histogram.
Scenes of high contrast, such as bright skies with dark foregrounds, can be a little more confusing to the metering system on your camera. Depending on how much the highlights dominate the scene, it may underexpose. If there are far more shadows in the scene, it may overexpose. You can choose to take a test shot and simply adjust your exposure compensation accordingly, or you can use the spot meter and place it on a middle tone area of the scene to get a more accurate metering of that part of the shot.
Backlit, low contrast
Low contrast scenes will probably require you to use spot metering, as you did with the high contrast scene. You can place the spot meter on an area away from the brightest, or darkest, areas of the shot and meter from that. Again, depending on personal preference, you might want to add positive, or negative, exposure compensation, if you feel it is required.