Need help here everyone please. I just bought a brand-new 24-70mm lens for my 5D and have been using it for less than 50 shots. Today I notice there is a black dot when I look through the eyepiece. Though it was from the front of the lens I looked but couldn't find any. Then I removed the lens and look through the eyepiece, I can see a lighter dot in the same position. Where does it come from, why it is light without the lens? and why it gets darker with the lens? By the way, the pictures do not seem to be affected by this dot at all.