I've been wanting to create a reel scanner for a long time. The hardest part for me was getting the right lens for the camera to capture a slide. It was basically a trial and error. Tried 25mm 30mm, 12-50mm, and a combination of extension tubes to get the right level of zoom. I found that the 30mm with a 5mm extension tube was the best solution.
Aside from that, the second most difficult item was the reel mount. This is the part that the reel sits on and has magnets to hold the reel down flat. I must have printed out a dozen of these things with very small adjustments each time. Every time I changed something, I saw a way to make it just a bit better.
I used the FastLED library to control the backlight LEDs. I thought I needed RGB LEDs so I could do some color correction for the older slides that don't have KodaColor and have faded. But found that I get little improvement from this because the USB camera has auto-white-balance and it does a pretty good job with color fade adjustments by itself. But I can still adjust the brightness using the FastLED library. I also started with the ring LED and later moved to the Jewel LED for more even light distribution on the slide.
I think I did a good job with the 3D parts to print. They fit together nicely and the tolerances are good. The final outcome of the scan is pretty decent. I have a video of the build and a link to the videos this creates. The scan process is automated so it will align to the 1st slide and then start scanning each slide automatically.
I then have to run the captures slides through a processor. This is using the Tesseract library to capture the text. It will then automatically rotate the slides and create a side-by-side (SBS) image with the text.
Last step is that I open a project in DaVinci Resolve and change the root directory to the slides captured. It will automatically change the video content and I can just press the render button. Each video is exactly the same for length, timing, and audio.
Video of the build:
Links to the videos this creates:
Please use the Github link for the source and STL files.