Perceptual Megapixel: Lens Sharpness Boiled Down to a Single Number

Modulation Transfer Function (MTF) charts are a very commonly used tool in the photo industry for measuring and describing how sharp a particular lens is. However, it's a system that is largely enigmatic to those outside the realm of optic experts and camera gearheads.

For those of you who don't want to learn how to read MTF charts, camera gear testing service DxOMark has announced a new metric that boils a lens' sharpness down to a single easy-to-understand-and-compare number: the Perceptual Megapixel.