Thick clouds give a very even light across the sky, which seems to penetrate into the forest better than any other weather condition. It was raining lightly when this picture was made and it was responsible for the light background. Without the rain you would have seen the dark trees of the forest covering the distant mountain. Although this picture looks nicely well lit, in fact it was a rather dark day. Note the long exposure time of 4 seconds at 2:00 in the afternoon.