WHAT IS EXPOSURE COMPENSATION?
When you take a picture with your camera in Full Auto mode, the camera calculates a setting based on what it believes to be a proper exposure and takes a picture.
When you use manual mode(M), you’re setting the exposure yourself, instead of relying on the camera.
When you use semi manual modes such as, Program(P), Aperture Priority(A or Av), Shutter Priority(S, Tv), you’re able to adjust the exposure set by the camera.
Exposure compensation is a method used to adjust the initial exposure set by your camera.
If you look in your view finder you’ll see a scale with a +, – with a 0 in the center. That’s an exposure level indicator that show whether the image you’re about to take is overexposed(too bright) or underexposed(too dark). If it’s tipping toward the +, it’s overexposed and if it’s tipping toward the -, underexposed.
When you’re shooting in Program(P), Aperture Priority(A or Av), Shutter Priority(S, Tv) mode on your camera, the camera sets its shutter speed or aperture setting based on what it believes to be the proper exposure. The dial will be at the center, 0 +/-, on the exposure level indicator.
WHY USE EXPOSURE COMPENSATION?
Most of the time the camera gives you good results. However:
Reason #1: There may come a time when you want to have some creative control over your images by adjusting the exposure.
Reason #2: Depending on your lighting condition or what you’re photographing, the camera may get tricked and not expose correctly or the way you want it to look.
What do I mean by tricked? Our eyes are way more complex than our cameras, so the camera doesn’t see everything we see.
Here are three most common situations when your camera may not give you an exposure you desire:
1. When photographing black objects (or dark)
2. When photographing white objects (or light)
3. When the background is brighter than the subject you are photographing
If you care to know more about why your camera gets tricked and exposes incorrectly at times, be sure to read my article on metering.
HOW TO USE EXPOSURE COMPENSATION
If you want to get on with your shooting, here’s my quick answer on how to use exposure compensation.
First, keep in mind that the exposure level indicator does not have to be at the center, 0. It’s ok to adjust it to go below or above the zero mark.
If your photo is turning out too bright(overexposed), dial down toward -. This is done in 1/3 or 1/2 increments. Sometimes even if the exposure indicator is at +/-0, your image might be too bright. So, it’ll be ok if you dialed it down below the zero mark.
If your image is darker than your want(underexposed), dial up toward +. Sometimes even if the exposure indicator is at +/-0, your image might be too dark. So dial it above the zero mark.
Each camera is different on how you dial up or down to adjust the exposure. So make sure to read your camera instruction manual. It’s typically adjustable by a dial or a combination of pressing the +/- button while dialing.
The sample photos below were taken at aperture priority mode. The first picture of salt is what the camera setting gave me. Notice how it’s a bit underexposed? So I used exposure compensation and dialed up by +1, for a proper exposure.
The first picture is actually decently exposed. However, a slight adjustment of dialing down by -1/3, using exposure compensation gave more of an accurate exposure.
As I mentioned earlier, this was a quick explanation of why and how to use exposure compensation. If you care to know more about why your camera gets tricked and exposes incorrectly at times, be sure to read my article on Metering.