Opal Pool

Opal Pool is a vivid hydrothermal feature in Yellowstone's Midway Geyser Basin, known for its striking blue and green water set against a rim of bright orange and yellow microbial mats. The boardwalk loop around the basin puts you at a fixed but well-positioned elevation above the pool, so work with a wide angle to capture the full sweep of color and steam, or zoom in tighter to isolate the surreal mineral textures along the edges. Early morning is ideal, when cool air causes steam to rise dramatically off the hot water, adding atmosphere and depth to your shots. Overcast days also work well by softening harsh shadows and making the colors pop more than in direct midday sun. A 24-70mm range covers most compositions here. Stay on the boardwalk at all times, as the ground around thermal features is dangerously thin. (Yellowstone National Park, Wyoming, United States)