How to Use +/- EV to Correct Photo Exposure

When using semi-automatic shooting mode like A/AV-Mode or S.TV-Mode, sometimes you may find the photo is over or underexposed. By adjusting aperture (in A/Av-Mode) or shutter speed (in S/Tv-mode), there will be no cure on the problem because camera will automatically change the counterpart to reverse the effect. The correct method to do it is to use “+/- EV” button on your camera. Let’s see how to do it.

Understand when your photo will be wrongly exposed.

There are two very common situations that your camera metering sensor will make a mistake:

Taking a photo on bright object – like the sun or sky. Your camera will think it is bright so it will lower the exposure – making the photo under exposed.
Taking a photo on dark object – like black graduation gown or dark cave. Your camera will think it is dark so it will increase the exposure – making the photo over exposed.

Let’s check out an under-exposed example:

Camera meter thinks the snow and sky are bright so it decreases the exposure.

By adjusting the +/- EV button, we can correct the exposure directly.

No matter you are using DSLR or mirrorless camera, you will have a +/- EV button / dial just like the following:

How to know when to increase EV and when to decrease EV?

Sometimes it is confusing to decide when to increase (+) and decrease (-) the exposure. Actually there is a “formula” we can use:

Increase (+) if it is bright. Decrease (-) if it is dark.

That means when you encounter bright object like the sky or sun, increase (+) the EV. When you encounter dark object like a cave, decrease (-) the EV.