There are countless articles online covering how to do these conversions. Most of Kodak’s older cameras fall into one of the following categories:
These are larger reels, so some form of adapter/spacer is needed.
This guy uses home made adapters constructed of dry wall anchors and cut up 120 reels. Its not necessary to mask the image down to 6×4.5 as he had done, however some minimal strips along the top and bottom of the opening into the bellows may make sense to support the film during transport – and to keep it FLAT during exposure.
The numbers on the backing paper will not line up with the window. I’m planning on using a double roll of backing paper (to simulate the right thickness) with the camera open, and wind the double thick paper through the camera to note how many turns I would need per frame. This will of course vary by camera and desired frame size, and is inexact at best.
No longer made, but is really just 120 film on a narrower, smaller, and slightly shorter spool. The connections are not quite the same, and due to tolerances its just not normally possible to fit a 120 reel into an unmodified 620 camera. Some cameras allow 120 reels for take up which is nice.
The solution I’ve chosen to do is to use my changing bag and reroll 120 film onto a 620 reel. Its not that hard, and plenty of video tutorials are available on YouTube.
This can be bought online where someone else has done the work for you.
No sprockets, narrower than 120, wider than 35mm.
Typically used in box and other simple cameras. Notably Ilford still makes this, but only in 100ft reels. It can be bought at various locations online through repackagers. Kind of pricey.
It’s also possible to load 35mm into 127, but you’ll need enough 127 reels to pull it off, as well as cut down liner paper from a roll of 120. Again, plenty of YouTube videos.
Finally, some guy figured out how to use a cigar cutter to cut down a spool of 120 film.
For development, luckily Patterson reels still have a standard adjustment stop for developing 127 film.