This talk is about a revolutionary camera concept called "flutter shutter". Flutter shutter cameras promised to increase the image quality when photographing moving objects. The talk gives a mathematical theory and formulas that answer the questions on these recent camera designs. The theory is also proved to be valid for the "motion invariant photography": the only other competitor of the "flutter shutter." An unexpected consequence of this theory is the existence of a filter that makes blind uniform motion blur deconvolution well posed for moderate blurs.