In general, in the summer, the sun rises over the right shoulder of Half Dome and sets over the downstream end of the Merced, shining up the valley, which runs mostly East and West. Places like Upper Yosemite Fall get sun early and mid-day and then drop into shadow in the afternoon. Mist Trail in open shade early, sunlit through the daytime and back in shade later. I'd carry a polarizer and a light yellow but not a red.

Don't drink the water without running it through a filter. Beaver and Guardia. Big crowds in the summer but once you get 50 yards off trail you'll be alone. Crowds are all in the valley, Glacier Point and Tioga Road turnouts.

They have let the valley absolutely grow up solid with trees. The indians used to burn it out every decade or so to keep it clear.

It's an absolutely fabulous place. You'll go a little nutty.