A common problem for people using automatic cameras (like webcams) is that the details of the subject are lost. The subject appears too dark or too bright. There are a few easy solutions that don’t involve buying a fully manual camera. This applies to faces as well as objects.
The solution: average brightness in a scene
Your camera will try to adjust to the average brightness / darkness of a scene. If a scene is mostly dark, the camera will try to brighten everything up. If the scene is mostly bright, the camera will try to make everything darker.
This works the same way with dark stuff