The light meter in your camera is stupid, some of the time.
For example, this white hydrangea in the sun, is too dark.
The flower actually more looked liked this.
Light meters "think" everything is average toned.
So, when you photograph something that doesn't have an average tone, the exposure will be too bright or too dark.
|If the subject is bright||the exposure is too dark.|
|If the subject is dark||the exposure is too bright.|
Here's a photograph taken from a cliff of a snowy valley.
The light meter measured lots of sunlight reflecting off of the snow.
The light meter set the exposure to make the snow look average—gray./p>
The valley actually looked like this.
There's an example with black gloves on the next page.