Posted August 27, 2012 by Gavin Hoey in Articles

Exposure Compensation ~ Basics

expo compIn my book there are two fundamentals to what makes a photo good or bad and they are proper focus and a perfect exposure. Get either of these things wrong and you’re fighting an up hill battle from the off.

In this post I’ll look at exposure compensation which allows you to override the camera’s suggested exposure and make your image lighter or darker as you require. Although the name may vary a bit, almost all cameras have this function. You’re looking for a button that has a half white, half black square and has the plus minus symbols… Basically something like the image on the right.

Why compensate?
In this modern age of digital everything you may be wondering why the cameras exposure wouldn’t be right all the time. By now some boffin must have figured out a way to get the perfect exposure, right? Well that’s nearly right and every new camera that comes out gets better and better at nailing the exposure but there are two problems. Firstly all metering systems start with the theory that the world (on average) is a mid grey, That’s great most of the time except for the times when it’s not, like when photographing snow or someone wearing black.

0 stops    1 stops
The white shell in the centre of the frame has caused a small amount of under exposure.
Dial in +1 stop of exposure compensation and the exposure is correct.

The second problem is exposure is often open to interpretation. A scene where the exposure is biased to highlights will look very different to one where it’s biased to the shadows.

Compensation in action
If you move the exposure compensation to the left you’re adding negative exposure and your photo will be darker. This is great when photographing dark subjects or when you want to capture highlight detail.

Moving exposure compensation to the right makes your photo’s brighter, perfect for photographing light things like snow, sandy beaches and backlit scenes.

-2 stops-1 stops0 stops 1 stops 2 stops
Click on an image to enlarge

When in doubt try taking the photo at a couple of different exposures but always remember once you’re done with exposure compensation reset it to zero.

Fix it in Photoshop
I love Photoshop but fixing exposure in Photoshop isn’t a long term plan you should stick with. Yes I know the RAW format gives you latitude of exposure you don’t get in JPG but adjusting exposure AFTER you’re taken the image will slow your workflow down and degrade the image. Both of these things may be slight but they add up. More over getting the image right in camera helps you to see the photographs not just take them.

Gavin Hoey