I didn't really see them like in the first photo (not that black), but they are also darker than in the second one, like dark shadows...
My image is flat (I cannot see the filaments), but just imagine something like this image without the filaments:
http://static.ddmcdn.com/gif/blogs/d...140509-jpg.jpg
It is probably normal, I was just wondering if there was a reason for the visible differences.