GrayZone vs ZoneCalc
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
GrayZone
This app acts as a precise light meter for photographers, allowing you to measure light in specific areas of your scene. It helps achieve consistent exposure and accurate tonal representation, especially in challenging lighting conditions.
- Zone System Mode for tonal analysis
- Real SPOT metering for selected areas
- Direct exposure control with ISO, shutter speed, and aperture
- Live preview with native sensor ratio
- UI color inversion option
- No ads or data collection
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GrayZone reads light where you decide — not where your camera guesses. Built by Max of max&douglas — professional photographer with 25 years in editorial and advertising photography. Zone System Mode Measure a reference area first (Zone V), then check where the other tones will fall and their relative EV difference, for precise and consistent exposure. Real SPOT Metering Reads light exclusively in the area you select. Ideal for portraits, complex lighting and critical situations. Calibrated to render the selected area as neutral gray. Direct Exposure Control Set ISO before metering, like a dedicated light meter. Instant precise combinations of shutter speed and aperture. Exposure lock with AE LOCK. Half-stop support for finer control. MANUAL mode with over/underexposure scale. Essential Interface Live preview in your sensor's native ratio. NEW UI color inversion Shows only what you need. Nothing else. Complete Privacy No ads. No photos saved. No data collected or transmitted. For manual shooters — on film or digital. It does not replace your camera. It works alongside it.
ZoneCalc
This app assists photographers in precisely calculating exposure and tonal placement using Ansel Adams' Zone System. It offers features for metering, reciprocity correction, and development adjustments, with options for multi-point measurements and data export.
- Zone System exposure calculation
- Multi-point metering
- Reciprocity correction
- Development adjustment recommendations
- Film-specific development times
- Calculation history and export
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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.
Screenshots
Verdict
The clearest difference is price: ZoneCalc at Free against GrayZone's $2.99. ZoneCalc also leads on rating (5.0 vs 2.8). GrayZone's advantage is in-app purchases (none vs 1) and update cadence (weekly vs every 3 weeks). On ratings volume, ads, device support and iOS requirement there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
ZoneCalc is free to download; GrayZone costs $2.99 up front. ZoneCalc sells 1 one-off in-app purchase. GrayZone asks for nothing beyond the download.
ZoneCalc holds the better App Store score, 5.0 against 2.8. Both are backed by a comparable volume of ratings — 5 and 2 respectively.
GrayZone ships an update weekly, ZoneCalc every 3 weeks. The most recent releases landed on September 22, 2026 and September 26, 2026 respectively.
| Parameter | GrayZone | ZoneCalc |
|---|---|---|
| Price | $2.99 | Free — better |
| Rating | 2.8 (5 ratings) | 5.0 (2 ratings) — better |
| Positive reviews | 62.5% of reviews | — |
| Number of ratings | 5 — better | 2 |
| Update frequency | Weekly — better | Every 3 weeks |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Paid | Freemium — better |
| Best chart rank | #17 — better | — |
| Devices | iPhone | iPhone |
| Requires iOS | 18.6 | 17.6 — better |
| Further details — not scored | ||
| Size | 3 MB | 3 MB |
| Age rating | 4+ | 4+ |
| Developer | Massimiliano Schenetti | Juergen Suk |
Customer experience
GrayZone
ZoneCalc
In-app purchases
GrayZone
No in-app purchases
ZoneCalc
- ZoneCalc Pro$3.99








