One Film One Subject is a collective category based around the idea of using an entire roll of film for just one specific subject matter.
I started this as a challenge to hone my creativity and improve my keeper rate when shooting 35mm. It may not seem like many shots, but being strict with your subject matter forces you to engage with the theme and becomes quite a challenge toward the end of the film. Themes can be things like unsmiling portraits, or a repeated composition in different circumstances, or simply just using a particular unusual focal length.
This category should, over time, fill up with an interesting and varied selection of mini-projects, all with very different thematic content.