Wrong normals in some faces

Hello, Blender friends,
I write because I met a problem with the objects created in a blender.
Some face’s have wrong normals (they are rotated by 180 degrees) - that mean’s the “front” of them is on the wrong side. This is a big problem, because I have to export the models to an external graphics engine, and the bugs of this type hit eyes so much…
Must be said that the problem occurs before exporting, because even in a blender render presents these bugs.
Some screen’s:
Light in front of object (some faces are dark…)
Light on the “back” of object (some faces are bright…)

Like i said, some of the faces are getting darker, when they should be brighter and vice versa.

How can I fix that, and how can I prevent this in the future.

Thank’s for help.


Have you tried “recalculate normals”? It is Ctrl-N I think. It is also on the panel on the left side of the editing screen. Hit T to bring the panel up.

Great fix, Thanks!