What is the minimum resolution for photos?

Photos must be at least 2500 pixels either long or wide, for example 2548x2036. In theory, any 3.2 megapixel camera set on it's highest setting will satisfy this requirement.

We raised this from the old minimum resolution because most consumer cameras (and cell phones) are capable of producing much higher resolution photos. Please don't resample photos to make them bigger, but set your camera or scanner to record a higher quality photo instead.