This is a photograph taken in May, 2013 just north of Creston, Iowa. A line of storms had just passed through before sunset and this photo was taken as the sun was getting very low in the sky. Some of the clouds were still in bright sunlight, others were in shadow while this brown cloud was lit by the lowest bit of sun.
Camera used was the Panasonic DMC-L1 with an adapted OM Zuiko 24/2.8 lens. Image processed in Lightroom.