Halo (religious iconography) between the alternative terms in English is rather unclear. The oldest term in English is "glory", the only one available in the Middle Ages, but now largely obsolete. It came from the French "gloire" which has much the same range of meanings as "glory". "Gloriole" does not appear in this sense until 1844, being a modern invention, as a diminutive, in French also. "Halo" is first found in English in this sense in 1646 (nearly a century after the optical or astronomical sense). Both "halos" and "haloes" may be used as plural forms, and halo may be used as a
Aureole effect plane. Although the focused (light) ray cones are actually more or less parallel to each other, the rays from the aureole effect appear to be radiating from the shadow of the viewer’s head due to perspective effects. The viewer's line of sight is parallel and lies within the cones, so from the viewer's perspective the rays seem to be radiating from the antisolar point, within the viewer's shadow. As in similar antisolar optical effects (such as a glory or Heiligenschein), each observer will see an aureole effect radiating only from their own head’s shadow. Similarly, if a photographer holds their