Thanks for the bug hint! I currently undecided on how I want to implement different film sizes. As of now each film shows in the details section the other available formats and I might make them filterable. Most of 120 films are also available as 35mm but I am aware of some exceptions. What do you think?
Adding it as a filter would be fine: some of the other info in the sidebar could be useful as filters as well, like the use cases. Also, comment from a friend who is more pro than me would be to add reciprocity compensation information.
Love it. Those are actually also on my feature roadmap! :)