Storm Thorgerson belongs to a very exclusive club of well-known album cover artists. Honestly, the only other one I can think of is Roger Dean, and just as Dean is closely associated with one band (Yes), Thorgerson is renowned as the photographer behind the light-refracting prism, the flaming handshake, and the field of hospital beds. Although he created covers for groups as varied as Def Leppard and The Cranberries, Thorgerson will always be remembered as Pink Floyd's favorite coverman.
This is also because Thorgerson didn't just work for Pink Floyd, he was also their close friend, going back to their early days with Syd Barrett. So the art director had a lot of stories to tell about his friends/clients. In 1997, he shared them in Mind over Matter: The Images of Pink Floyd. The natural draw of this book was Thorgerson's pictures (my favorites: a clutch of inflatable pig outtakes from the Animals shoot), but he also proved himself to be a natural and humble raconteur, telling tales of his darkroom methods and inspirations in a manner that should be understandable even to those who'd never even dropped off a roll at the Fotomat.
Storm Thorgerson died in 2013, but Mind over Matter is now being republished by Omnibus Press for the book's (almost) thirtieth anniversary. A slightly odd aspect of this reprint is how it waits until its final page to acknowledge Storm's death, so it's a bit jarring reading David Gilmour's 1997 introduction, in which the guitarist speaks of his photog buddy as if he's still with us. Eerily, reading and perusing the images in his book today, it feels like he still is.