We have a large collection of 35mm photo slides. Some were taken by my father-in-law in the 1950s, 60s, 70s and 80s. Some were taken by me or my wife in the 80s and 90s.
I want to digitise these, and I took inspiration from various projects documented on the web, the common approach being to use a DSLR camera and a Kodak Carousel slide projector. I used an ESP8266 microcontroller to trigger the projector to advance form slide to slide, and trigger the camera to take photos.
The project is documented more fully here. With my rather ancient Panasonic G1 camera, and a class 10 memory card, I found I could take process one slide (with three bracketed images) in around 6 seconds. Thus a full, 80-slide carousel can be processed, unattended, in about 8 minutes.