The chart doesn\'t mention the aperture, or what was plotted. When I went to the Canon site I came up with this explanation:
\"Canon\'s MTF charts give results at two apertures: wide-open, and stopped down to f/8, with the lens set to infinity focus. While MTF charts don\'t include many factors that can be important when selecting a lens (size, cost, handling, closest focusing distances, AF speed, linear distortion, evenness of illumination, and of course features like Image Stabilization which may produce superior real-world results), they can indicate to the knowledgeable reviewer some of the optical characteristics they can expect from a particular lens. \"
In other words, the top two pair of lines are for f8 performance, the bottom two f1.2. It doesn\'t look so hot at f1.2. The Leica at f1.4 spend most of the plot in the 90% range. The Canon spends most under 70%.
The chart doesn\'t mention the aperture, or what was plotted. When I went to the Canon site I came up with this explanation:
\"Canon\'s MTF charts give results at two apertures: wide-open, and stopped down to f/8, with the lens set to infinity focus. While MTF charts don\'t include many factors that can be important when selecting a lens (size, cost, handling, closest focusing distances, AF speed, linear distortion, evenness of illumination, and of course features like Image Stabilization which may produce superior real-world results), they can indicate to the knowledgeable reviewer some of the optical characteristics they can expect from a particular lens. \"
In other words, the top two pair of lines are for f8 performance, the bottom two f1.2. It doesn\'t look so hot at f1.2.
