Exposure Compensation Button
Explanation: While you hold this button pressed you can set an adjustment to the automatically measured exposure with the main command dial at the back. The compensation is defined in „exposure values“, one exposure value (i.e. display of +1.0 or -1.0) means an exposure with a the double or half quantity of light respectively, so double or half of the initial exposure time or an aperture of one f-stop bigger or smaller.
In the custom setting menu
b3 Easy exposure compensation you can simplify the setting of an exposure compensation so that turning the sub-command dial at the front does the same.
Tips: Important setting! A correct exposure is not only crucial for the look of your images, you also have hardly a chance to save completely over- or underexposed parts of your picture later on in the computer. Therefore it is best to set an exposure compensation already while shooting.
Every camera – even the most expensive professional one – needs regular exposure compensations! No matter how much electronics you put in, it can only measure the incoming quantity of light. But it cannot recognize f a certain part of your picture is a brightly lit grey or a white area in dim light and how you want it to appear on your picture. That‘s still the same as in decades of photography before the digital era.
More difficult than how to dial in an exposure compensation is the decision when you should set which amount of compensation. That is a general topic which does not fit into this description of camera settings.
The most reliable way to judge about the exposure is to check the RGB histogram on the monitor after taking a picture. See the explanations about the Multi selector and the playback menu RGB histogram.