Mostly a copy from my comment when this was posted elsewhere.
I wish he went a little more into the microdot stuff and tried a little more for getting that small size down. Intelligence agencies aren't the only ones who use microdots/micro print so there should be information out there.
If you want a more in depth look at just the photography stuff, Alec did quite a deep dive. https://www.youtube.com/playlist?list=PLv0jwu7G_DFV6yW240e6CbiwCLaZ0Z6PV He also made a video about his development process, at least for color, and put that on conextras https://www.youtube.com/watch?v=rW1cg3hDdc4
As a note, youtube seems to have changed something with metadata recently so when lemmy instances not based in the US populate, you only get a generic bit about what youtube is in the local to the instance language, as opposed the the video description. https://yiffit.net/post/11721047