Intensely green river turns air purple

While walking along the Chicago Riverwalk with my wife, the river had just been dyed green hours earlier for the annual St. Patrick's Day festival. The river has a surreal green glow that could be seen in the metal under the bridge. Knowing that HDR photos bring out the the slightest bit of color, I knew that the green under the bridge would be captured. What I didn't foresee was the purple tones in the background. The intense green forces the background into a purple tones with the blues from the sky. The Wendella boat roaides can be seen in the left background.

This massive double-leaf, double-deck bridge is constructed with a split down the middle between the two directions of traffic. Walking under the bridge, you can definitely see bright light shining between these two sections. Especially cool here is how that light is a purple light. You can also see how the light falls onto the river.

With the longer exposures of an HDR photo shot at f22, the river gets a smooth ice-like look.

More explanation about why the background turned purple, with color theory and diagrams at my blog post "Insanely green river turns air purple"