This is an awesome photography spot in Portland with great reflections off of the river and is only about a two minute walk from parking.
Starting at OMSI, walk towards the Hawthorne bridge, and away from the Tillicum bridge. After about a tenth of a mile, you will see a dock and the Hawthorne bridge. Walk down on the dock, or take pictures from above. For added adventure, walk under the Hawthorne bridge and take pictures from the other side!