The Eastman Museum of photography has a newly expanded collections hub with 250,000 records, many with pictures. Some of the scans are quite large, such as this 2380px scan of a Minor White picture…

catskeleton1953“Cat skeleton”, Minor White, 1953. Eastman Museum.

To get big pictures suitable for lecture or dissertation use, you need to use the Firefox trick and a Firefox add-on like RighttoClick.