Exposure Compensation: How to Use it Correctly and when
Exposure compensation (also known as Exposure Control) is used to alter the exposure from the values chosen by the camera.
The picture above is an underexposed image. The camera settings did not do an excellent job of exposing the scenery. With the Exposure Compensation, we can easily increase the exposure up a bit by +1 EV to brighten up the below image.
Exposure is simply the amount of light entering your lens and then reaching your camera's sensor. Exposure is measured by three key elements – Aperture, Shutter Speed, and ISO. These three elements work together and can be adjusted individually to capture the right exposure.
Using Exposure Compensation is an easy way to override your cameras auto exposure setting in order to get the most accurate exposure for you shot.
Exposure Compensation works when you are using your camera's metering system,This can be Shutter Priority, Aperture Priority, Program Mode, or other Scene Modes. It will not work in Automatic mode, and will only work in Manual mode when you are using your Auto ISO.
How It Works
Not all cameras Exposer Compensation buttons are located in the same place but will likely have a + and - symbol and they should be easily recognized. Hold this button down and use you rotating dial to either increase or decrease your exposure your exposure values depending on the lighting situation. This will increase or decrease your exposer by 1/3 of a stop as the number of stops decreases or increases.
Depending on which mode you're in Exposer compensation works differently.
Shutter Speed Priority Mode: If you’re in Shutter Priority, your Exposure Compensation will automatically adjust the Aperture values.
Aperture Priority Mode: On the other hand, if you’re using Aperture Priority Mode, then your Exposure Compensation will compensate by adjusting the shutter speed to either lighten or darken your image.
Program Mode: This one is a little different depending on your camera. In Program Mode, the Exposure Compensation may adjust both aperture and shutter speed. Check your camera’s manual for exact information.
Manual Mode with Auto ISO will ether either lighten or darken your image by adjusting your ISO.
Exposure Compensation On Your Camera
This all depends on the camera you’re using and is usually easy to find.
Usually, for Nikon, it is located next to the shutter release button with a +/- button. You’ll hold and press on this button while turning the dial to adjust it quickly and hassle-free.
On Canon DSLR cameras, the button is typically located on the back of the camera with an “AV” button labeled.
Mirrorless camera users can usually find it on top of the camera as a dial.
When to Adjust Exposure Compensation
What can often happen in a scene like the one above while shooting in a metered mode is the camera will read the bright background as a normal medium gray tone. This results in an underexposed subject. To combat this, you’ll want to increase the Exposure Compensation to about 1-2 stops higher than normal. Play around with the different increments to get the perfect exposure.
You will want to add Exposure Compensation when your subject or scene is bright and overexposed, like this Gull, or a white sandy beach. The camera meter will try to underexpose your image, so make sure you are dialing it up a few stops on your camera when you are shooting an overly bright subject.
When To Decreasing Exposure Compensation
You will want to lower your values if your subject or background is dark and you are in a metered mode. When you point the camera to a dark surface or subject, more likely than not, your camera will try to overexpose the image. Knowing this, you’ll want to dial it down a few notches to balance out the exposure.
An example of when you’ll want to decrease the Exposure Compensation is when you come across a dark subject or scenes like this Summer Tanager. Your camera is detecting the scene as darker than 18% grey, then it will compensate by overexposing your image.
Adding Exposure Compensation to your daily shooting is an easy and quick way to control the exposure. Experiment and learn about your camera’s capabilities so you can get the perfect results you are looking for.