Exposure compensation

Tuning brightness

Your camera will measure the available light to determine the exposure. Sometimes you may want to tune this value by a bit.

Why compensate?

Exposure compensation is probably the first setting that photographers learn to adjust. It is not a complete setting, but a mere adjustment to the exposure value suggested by the electronics.

The exposure value is determined by the available light, and generally a digital camera is an excellent measurement device for how much light there is. But, the electronics can only determine an average value, if there is a very bright light source, the electronics will see that there is too much light and decrease the exposure time. Or only some parts of the picture may be in the light, while others are darker. Electronics will think it is too dark and increase the exposure. Imagine you are in a tunnel, do you want to have a picture where there is a bright light at the end of the tunnel, or do you want a dark picture and see only what is visible at the end of the tunnel?

When the electronics do not get it perfectly right (but close enough) you can try to help things out by manipulating the exposure compensation.

A positive compensation means that you want to make the scene brighter, exposure time will be more than what the electronics calculate.
A negative compensation is the opposite, the scene will become darker by decreasing the exposure time.

Usually the increments in exposure compensation are in 1/3 steps (of f-stops), which in practical terms will move you to the next exposure value. i.e. 1/100s will become 1/125s.

The most obvious case for exposure compensation is the relative location of the sun. You can say when the sun is on the side stay neutral, when it is in back go 1 or 2 stops negative and when it is in front of you go 1 or 2 stops positive.

There could be some lens dependent compensation as well. For example for the Nikon 70-300, I usually end up having -2/3 (or -0.7 as displayed) as a default setting (Check the EXIF data for the pictures I have for this lens, it is listed under Metadata with the entryAPEX exposure bias).

Tips and Tricks

When you are shooting against the sun, you will need positive compensation
Similarly with the light behind you, usually a negative compensation will help.
Mirrorless cameras and cellphones can directly show the brightness of the image on the EVF or screen allowing you to judge and compensate better
There are other ways of manipulating the exposure, that are also quite easy. There is usually an auto exposure lock (AE-L) function, that will allow you to point to somewhere where you get the exposure set, and the while keeping the button pressed you can re-frame the shot. This helps a lot with a framing that wants to capture something on the ground, but tries to frame it with more sky. As the sky is brighter, the electronics will end up increasing the exposure time which will make your scene darker than you want.
Another issue is that the center of the image may be more important than the rest. In these cases, changing the metering method used for the exposure from full-frame to center weighted may help a lot. Flowers and macro shots work usually better with a center weighted metering.
Exposure compensation works better when there is enough light (i.e. 1/60s and more), indoors, or for dusk/dawn/sunset situations the light changes too quickly and too subtly, often fooling the electronics. It is easier to move to a speed priority shooting mode in such situations rather than play around with the exposure compensation. Just set the exposure value you want manually.
Compensation works the best to make a consistent correction (i.e. for a lens) the other tricks can be used in addition for certain conditions.
If you add compensation, the metering that you see in the display will take this in account. A typical problem is to first try with various exposure compensation options, then give up and change to manual or speed priority setting. By this time you perhaps have a random compensation added (like -1.3), and now when you try to reason about the exposure time (like 1/100s) on the metering in your display this will be still skewed by the compensation You have entered. Most cameras have a little (+-) icon displayed next to the metering to tell you that the metering has been adjusted according to some compensation.

These pages are for Amateur Photographers and not really for seasoned photographers and professionals. I have no affiliation or commercial interest with any brand/make. I write from my own experience. I ended up using mainly Nikon, so I am more familiar with this brand than others. See price for notes on pricing as well as photography related links.