A few months ago, a user on Reddit stumbled across a small collection of negatives and slides of photos taken by Bunny Yeager, specifically her very colorful self-portrait with a large format camera. The 4x5 Ektachrome 100 transparency is in pretty bad shape-- lots of cracks and spiderweb, and the whole thing has shifted massively towards "red".
The countless copies floating around on the internet may not have the absolute gob-smacking resolution or quality of the original-- but the original has deteriorated significantly as well.