Exposure Compensation
Your exposure (or EV) control is an extremely useful tool that can really make a difference. It is found on almost all cameras, both SLRs and compacts, and on nine out of ten it is in a logical place. Of course, camera manufacturers wouldn’t do that if it wasn’t a very useful little button.
You can use exposure compensation in all camera modes except auto (auto is usually indicated by a green square or a green camera on the dial). What it does exactly depends on your default setting. If your camera is in aperture-priority mode (Av or D), turning the +/- dial will make the shutter speed faster or slower. If your camera is set to shutter speed priority (Tv, T, or S), turning the +/- dial will increase or decrease the aperture.
For the photos above: The photo on the left was taken without corrections. The photo on the right was taken with corrections and reflective material.
When do you use exposure correction?
Suppose you have a photo like the strawberry tiramisu above. You can clearly see that the photo on the left is too dark in several places. The white of the table is not white and the shadows are very present. Whether you like it or not is often a personal choice, but in this case it did not give the sunny summer feeling I had in mind.
For the photo on the right, I used exposure compensation with a setting of +1. This is necessary because all the white in the composition causes your camera to get ‘confused’ and underexpose. You can compare this to the effect of snow on a winter sports holiday. The white of the snow reflects so much light that your camera will underexpose. As a result, when you return home, you will find that the beautiful white snow has turned very, very grey in all of your photos.
Bright or white subjects
The same thing happens with a white background, a white sign or a bright subject, as you can see in the first photo. The same thing – but in reverse – happens when you photograph a dark subject against a dark background. Your camera will actually overexpose. As with many things in photography, this is a bit of a confusing thing, and you might find that you are initially turning the correction in the wrong direction. I remember it took me a long time for the penny to drop. So, if you notice that your photo is getting too dark (for example, by looking at your histogram; see example histogram below), you can easily correct your exposure with exposure compensation, preferably in aperture priority mode. Turn the mode slightly to the + side and you will see that your photo becomes brighter and the histogram moves to the right. Turn it to the – side and you’ll see your photo darken and the histogram move to the left.
Please note! Exposure compensation does NOT work in manual (M) mode. This is because everything is under your own control.
Live preview
With more and more new camera’s having live preview, getting the exposure right has become so much easier to do. In live preview your camera shows you the approximate exposure already befóre you push the button. And using the exposure compensation will directly showing you if you’re turning it in the right direction too.
What is a histogram?
A histogram is a graphical representation of all the shades in your photo and is a useful tool if you want to know if you have an over- or underexposed picture. The histogram is usually located under the DISP or INFO button on your camera. If you have a Nikon camera, you often need to activate the information in your menu first.
You can also find the information in the software on your computer. This screenshot is from Lightroom and is of the Strawberry Tiramisu. When you look at the histogram, remember that light tones are on the right and dark tones are on the left. If you have a photo, like this one, that is quite bright, then most of the graph should be on the right. If you have a very dark photo, the histogram on the left will contain more information. If the graph is ‘stuck’ to the edge, it means that there is an overexposed area in your photo if it is stuck to the right, or an underexposed area if it is stuck to the left.
Also make sure you check out the articles on aperture, shutterspeed and ISO.
