On October 31, 1941 Ansel Adams was driving along when he noticed a scene that excited him. He quickly pulled over and set up his 8x10 view camera. In his haste, he couldn't find his Weston exposure meter. He remembered what the exposure should have been for one part of the scene and came up with an exposure of 1 second at f/32 with the ASA 64 film he was using. Although he wanted to take a second image, the light changed and the scene was gone. Imagine if Mr. Adams had an iPhone on that fateful day that he took what probably is his most famous picture...Moonrise, Hernandez.