William Guion, a photographer for 20 years, has adeptly captured the otherworldly majesty of the legendary live oak in “Silhouette Oak.” From South Louisiana, Guion began photographing the oaks, known in mythology as sacred beings with souls, when a mentor suggested that he photograph something that impassioned him. Guion only shoots in the subdued lighting of early morning, late afternoon or overcast days to reveal to the subtle details and tones of his subjects. Published in calendars, respected magazines and professional journals, Guion has also authored his own book about oaks called “Heartwood.”