Quote Originally Posted by benjiboy View Post
no lens gives it's best performance wide open it's against the laws of physics.
Nope. Not against the laws of physics.
In fact, a perfect lens, i.e., one without aberrations, has its resolution limited only by diffraction. The larger the aperture, the more the resolution. Every doubling of aperture diameter, e.g., f/8 to f/4, results in doubling of resolution.

It's just that in the real world things aren't as easy as that.