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 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