Self-supporting smectic bubbles consist of highly ordered membranes of nanometer to micrometer thickness. They can reach radii of several centimeters. Analogous to soap bubbles, they can be generated by excerting lateral pressure on a planar freely suspended smectic film. We describe the optical properties of these objects and the determination of the membrane thickness from transmission images. The dynamics of the growth and motion of holes (regions of reduced number of layers) on the bubble surface is briefly discussed.