Lol one more thing. The “Add” operation is often used to push pixel values above 1 for a brightening effect. So adding a 0.75 grey pixel value to a 0.5 pixel value takes you above 1: to 1.25. Commonly, your computer’s display has to normalize that value back to a 0-1 range and the result is an over-exposure effect.
Think a bout a lightsaber: The middle of the beam is white representing an above-1 overexposure. But as the beam fades outward it gradually becomes a color (like red for the bad guys). The fade into color represents pixel values that are gradually dropping below one and capable of showing color.
