Having walked up and down the river bank on Saturday, I realized that even with an overcast sky causing diffusion the sunlight was still angular.  This resulted in fairly flat tonalities within the foliage as seen below, but a noticeable amount of backlighting when looking in the opposite direction.  Both views were prone to photography, but the mood would be very different.

A view up the South Branch of the Raritan River. A line of lichen and moss covered rocks form a natural wall while leaves of yellow, green, and red fill the back of the frame. Taken with the Tamron 14-150mm Di III lens and the Olympus PEN E-PL3 micro four thirds camera.

A 10-stop neutral density was used in the above photo.  Without it, the running water lacked character.

Photo taken with the Tamron 14-150mm Di III lens and the Olympus PEN E-PL3 m43 camera.  Exposure settings: 50s F/9 ISO 200, 31mm