DisparaTimer vs PaperDeveloper

DisparaTimer is a mobile app that, when connected to a Raspberry Pico W/WH, can control the exposure time of a photographic enlarger using a power relay. The physical setup is inexpensive and easy to assemble. DisparaTimer has two operation modes. The first is a traditional timer mode, where you set a specific time for each exposure. The second is designed for creating test strips with constant fractional step increments over a base time. On iPad (iPadOS 17 and later), DisparaTimer includes a landscape-only notes panel that lets you add photos or images of your test strips and make handwritten or visual annotations directly on them.

PaperDeveloper is a precise darkroom timer for the full wet process of photographic paper. Set your paper, chemistry, dilution, temperature and volumes. The app calculates times from manufacturer data. The built-in timer guides you through every step — developer, stop bath, fixer, wash, and optional toning. Track multiple papers and test strips at once, and save quick presets. KEY FEATURES • Timing for the full B&W paper wet process • Papers, chemistry, dilutions and temperatures • Multiple runs at once (paper + test strip) • Presets for quick setup • Chemical capacity / yield tracking • Red UI for darkroom use • Works offline — no account, no cloud This version includes materials from FOMA, Ilford and Kentmere. Important: the red interface helps in the darkroom, but PaperDeveloper is not a certified safelight. Please keep that in mind. Enlarge — don’t scan!