Just watched it as a result of reading this thread. I loved the way the documentary was made with the interviewees in B&W whilst the historical images and film were in colour. Stylistically it reminds me of Powell & Pressberger's iconic film 'A Matter of Life & Death',
in reverse.
I could relate to the darkroom scenes: having to individually burn & dodge prints under the enlarger (in my case using my hand & fingers) and layering different images, cutting them, pasting a collage then copying that image with a copy lens (widest aperture for minimal depth of field) on my trusty Mamiya C330f TLR (with paramender to correct parallax when doing close-up images). I still have the TLR & Paramender. Ansel Adams' Zone System was applied from the taking to the printing of a b&w image.
Beautifully made & informative. I remember some of the record covers from 35 years ago, although my record collection is predominantly classical music.
Thanks for making it known.