Expose is the exposure calculator that thinks like a photographer. Spin one dial and the others keep your EV. Stack ND filters and see the real shutter time. Correct for reciprocity failure on 17 film stocks. No wasted frames.
Change shutter or aperture. The other follows, ISO stays locked, and the exposure doesn't move.
Three linked dials for shutter, aperture, and ISO. Stop down from f/2.8 to f/8 and the shutter slows three stops to match. You see every equivalent exposure at a glance, with the EV shown for people who think in EV.
Lock any dial to decide which value compensates. Most people lock ISO and trade aperture against shutter, so that's the default.
Pick any combination from ND2 to ND100000 and the stops add up for you. Meter at 1/125, stack ND8 + ND64 + ND1000, and Expose says 1h 9m 54s. It's shown in minutes and hours, not as a fraction you have to work out in the cold.
Shooting film behind the filter? Flip on reciprocity and the ND result is corrected for your stock right there.
Past about a second, film stops responding to light in a straight line, and each stock drifts differently. Choose your film, enter the metered time, and get the corrected exposure from that stock's own reciprocity curve.
Expose makes no network connections and needs no permissions, so it works on a mountain ridge, in a slot canyon, or in the darkroom. Your presets stay on your device.
You spend more than this on a single roll of film. Expose is there to make sure none of those frames are wasted.
No. Expose calculates from an exposure you already know, whether that's from your camera's meter, a handheld meter, or the built-in Sunny 16 chart. Once you have one correct exposure, it gives you every equivalent one plus the ND and reciprocity corrections.
Shutter speeds go from 1/8000 up to 4 hours, which covers long night exposures on film after reciprocity correction.
17 stocks from Kodak, Ilford, Fujifilm, and CineStill, including Portra, Ektar, Tri-X, T-Max, HP5 Plus, FP4 Plus, the Delta range, Acros 100 II, and 800T. Each uses its own reciprocity curve and threshold.
Completely. Expose makes no network connections at all, so every calculator works in airplane mode.
Yes. It's one purchase with every feature and every future update. No subscription, no in-app purchases, and no ads.
Dial it in, trust it, and take the shot.