Actinic

Actinic is a fast, fully offline exposure calculator built for film photographers — a film exposure calculator that also solves the one thing most light-meter apps skip: reciprocity failure on long exposures. Dial in a Sunny 16 reading or your own aperture, shutter, and ISO, then read the full wheel of equivalent exposures instantly — no camera permissions, no accounts, no network calls, ever. Shooting past a second? Pick your film stock — Tri-X, HP5 Plus, T-Max, Portra, Acros, and more — and Actinic corrects your exposure time for reciprocity failure using published manufacturer data, so your night shots and long exposures come out right the first time. — WHAT MAKES ACTINIC DIFFERENT — • Full-stop and third-stop exposure wheel — read every equivalent exposure combination instantly. • Sunny 16 quick-set — dial in a standard daylight reading in one tap. • Reciprocity failure calculator — corrects long-exposure times using published manufacturer data for stocks like Tri-X, HP5 Plus, T-Max, Portra, and Acros. • Fully offline — no camera permissions, no accounts, no network calls, ever. — PRICING — Actinic's free tier includes the full-stop exposure wheel with Sunny 16 quick-set, a reciprocity calculator with 3 built-in film stocks, and up to 3 saved camera + film presets. Actinic Pro is a one-time purchase — yours forever — that unlocks the full 12-stock reciprocity library, unlimited saved presets, and third-stop precision. — FEEDBACK — Made by a small indie team. Email obeliskclubclub@gmail.com with feedback, bug reports, or feature requests. Terms of Use (EULA): https://obelisk.club/filmexposurecalculator/terms