Lyle Rexer: The Edge of Vision: The Rise of Abstraction in Photography

They appeared in a period of upheaval. They saw the rebuilding of Paris, the rise of industrialism, the ruin of the Franco-Prussian war. They displayed their startling and shocking works in a series of exhibitions from 1874 to 1886. And by the 1890s, this "loose coalition" of artists who rebelled against the formality of the French Academy had created the most famous artistic movement in history. "They" were the Impressionists, and Professor Brettell is your expert curator and guide to a movement that created a new, intensely personal vision of the world.

Symmetry has a central role in the study of vision. The concept of symmetry has an ancient origin in considerations of visual appearance; in modern times, abstracted and formalized into Group Theory, it has found spectacular applications, far beyond the visible; but its importance for vision persists in many ways including: