By Jim Grant of San Diego (Scenic San Diego Photography, Green Flash). "These pelicans had been drifting along the waters edge and I finally got them where I wanted them and snapped this off........" ©Jim Grant, shown with permission.
|A rather broad and diffuse 22-degree halo. Small ice crystals 50 micron (0.05mm) across or less might have been responsible. Diffraction then starts to broaden the halo. An alternative is that the crystals had imperfect faces, trapped air bubbles or other defects.