I checked the Sotheby's website and saw a couple odd ones. The first was Dorothea Lange's Migrant Mother, and the second was AA's Moonrise. From seeing the other photos tat were taken there in Nipomo of the family shown in Migrant Mother, it was obvious that the kids were moving around and it seems odd that she would take the time to make a Polaroid before the real exposure. For Moonrise, all of AA's accounts of the day were that he saw that scene, jumped out of the car, and didn't even meter the scene because the light was fading fast. Are these actually just gelatin silver prints that were in Polaroids collection? There's not much of a description on the site, and it's horrid flash design isn't working correctly for me without freezing up firefox, so I don't plan to go over and look at it again.