Originally Posted by mattintosh /forum/post/18113237
The answer's in the question. I'll explain.
There are two types of reflection--specular ("reflection" in the colloquial, like a mirror) and diffuse ("reflection" over a broad surface). All reflection has both of these components, and except for the miniscule amount of light absorbed by objects, all of it is reflected.
So if a surface produces very specular reflections, it will have very low diffuse reflection and vice versa. If it's 80% specular, it's 20% diffuse, etc.
While diffuse reflection can go unnoticed and mess with brightness and color accuracy (because it doesn't produce a reflected image, it just washes out the screen), specular reflection just annoys you by blocking the underlying image (it has no impact on any part of the TV except where the reflected image appears). If you reposition the TV or yourself so you can't see specular reflections, the problem is gone.
It's the diffuse reflection you have to worry about, but if you can't observe a difference in performance with the light on versus the light off, then there is no problem.