ZoneCalc vs PocketMeter Pro

ZoneCalc — Zone System Calculator ZoneCalc is a precision tool for large format, medium format and 35 mm photography following Ansel Adams' Zone System. Built for photographers who work with a spot meter, develop their own negatives, and want full control over exposure and tonal placement. METERING In Classic mode, enter the shutter speed for the deepest shadow with detail (Zone II) and the brightest highlight with detail (Zone VIII). ZoneCalc returns the shutter speed for Zone V — 18 % middle gray — the exposure you set on the camera. Multi mode accepts any number of measurement points across the scene. The app auto-assigns each point to a zone; drag pins on the zone strip to express your creative placement intent. RECIPROCITY For exposures above one second, the Schwarzschild effect is corrected automatically: t_corr = t_nom ^ p, using the film-specific exponent. The corrected camera time appears directly in the result card. The shutter speed list extends to 30 minutes. Films with reciprocity data: Ilford HP5+, FP4+, Delta 100/400, Kodak Tri-X, T-Max 100/400, Kodak Portra 160/400/800, Leica Monopan. N-RATING & DEVELOPMENT ZoneCalc compares the scene's dynamic range against the film's usable latitude and proposes a development adjustment — N−2 through N+2. For each film, concrete times are shown for common developers: D-76, Rodinal, HC-110, XTOL, ID-11, T-Max Dev — with dilutions per Massive Dev Chart and manufacturer recommendations. HISTORY & EXPORT Every calculation can be saved with a note and the chosen developer; two entries can be compared side by side. The complete result — shutter speed, reciprocity, N-rating and development times — exports as an image for the darkroom or for sharing via AirDrop, message or mail. DESIGN The interface follows the visual language of classic Leica instruments: monospaced typography, warm amber accent, hard edges instead of rounded corners. Fully localized in English and German, all-dark throughout — optimized for darkroom and field use. ZONECALC PRO Classic two-point metering with Zone V calculation and the zone strip are free. The one-time Pro upgrade unlocks: — Multi-point metering with interactive zone assignment — Reciprocity correction and N-rating — Development recommendations with times per developer — Save, compare and image export One app, no subscriptions, no data collection. All calculations run locally on device.

PocketMeter Pro turns your iPhone into a professional light meter. Built for film photographers and cinematographers who think in stops, angles, and zones. Point it at a scene and get a live exposure reading, solved across real photographic stop tables. Lock any two of shutter, aperture, and ISO, and the third tracks the light in real time. Tap anywhere in the frame to spot-meter: the tapped area is placed at middle gray, exactly like a spot reading for shadows or skin. • Live scene metering read directly from the camera sensor • Tap-to-spot metering with one-tap return to full-scene evaluation • Lockable dials with a priority-aware exposure solver • Pop-up scrub wheels with haptic detents — it feels like a meter, not a form • Hold any reading while you work, then release to go live again • Over- and under-exposure warnings when a solve runs out of range CINEMA MODE • Shutter angle instead of shutter speed — 180° at 24 fps reads 1/48 • Frame rates from 23.976 to 60 • ND filters in cinema density notation (ND 0.3 to ND 1.8), right on the control deck — photo mode shows classic filter factors (ND2 to ND64) instead • False color, one tap from the viewfinder: an ARRI-style exposure map where green is middle gray, pink is skin key, and red is clipping — read relative to YOUR dialed settings, not the phone's auto-exposure ON SET, IN THE FIELD • LiDAR rangefinder: distance to your metering point in feet and inches (iPhone Pro models) • Live color-temperature readout in Kelvin from scene white balance • LOG: save a frame to Photos stamped with your full exposure — EV, shutter or angle, aperture, ISO, ND, white balance, distance — and geotagged, so you can swipe up later and see exactly where you metered it • Full portrait and landscape support with translucent controls that keep the viewfinder clear BUILT BY FILMMAKERS PocketMeter Pro comes from Studio C-41 and was built and field-tested alongside working cinematographers. Requires iOS 17 or later. Rangefinder requires a LiDAR-equipped iPhone (Pro models). Camera, Photos, and location permissions are used only for metering, saving your logs, and tagging them — nothing is collected or shared.