SlowLightMeter vs GrayZone
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
SlowLightMeter
This app provides a simple and accurate light meter for film photographers. It continuously measures light with minimal interaction and includes an ISO lock to prevent accidental changes. EV values are a core feature for ease of use.
- Reflective and incident light metering
- Continuous light measurement
- ISO lock
- EV value display
- Simple interface
Read full descriptionHide full description
As a film photographer, I wanted an accurate yet simple reflective and incident light meter. After trying several, I decided to build my own. This light meter continuously measures light, so it requires minimal interaction during a shoot. To avoid accidentally changing film ISO, I added an ISO lock. And since I shoot often with my Hasselblad, I made EV values a core feature of the app.
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
Read full descriptionHide full description
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.
Screenshots
Verdict
The clearest difference is price: SlowLightMeter at Free against GrayZone's $2.99. SlowLightMeter also leads on rating (5.0 vs 2.8) and review sentiment (100% vs 63%). GrayZone's advantage is chart position (#180 vs unranked). On ratings volume, update cadence, ads and in-app purchases 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
SlowLightMeter is free to download; GrayZone costs $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.
SlowLightMeter holds the better App Store score, 5.0 against 2.8. Both are backed by a comparable volume of ratings — 2 and 5 respectively. Written reviews point the same way: 100% of SlowLightMeter's written reviews are positive against 63% of GrayZone's.
SlowLightMeter ships an update every 4 days, GrayZone weekly. The most recent releases landed on September 18, 2026 and September 22, 2026 respectively.
| Parameter | SlowLightMeter | GrayZone |
|---|---|---|
| Price | Free — better | $2.99 |
| Rating | 5.0 (2 ratings) — better | 2.8 (5 ratings) |
| Positive reviews | 100.0% of reviews — better | 62.5% of reviews |
| Number of ratings | 2 | 5 — better |
| Update frequency | Every 4 days — better | Weekly |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free — better | Paid |
| Best chart rank | — | #180 — better |
| Devices | iPhone, iPod — better | iPhone |
| Requires iOS | 15.6 — better | 18.6 |
| Further details — not scored | ||
| Size | 1 MB | 3 MB |
| Age rating | 4+ | 4+ |
| Developer | Ari Jaaksi | Massimiliano Schenetti |
Customer experience
SlowLightMeter
GrayZone
In-app purchases
SlowLightMeter
No in-app purchases
GrayZone
No in-app purchases





