Zone Tool vs Spot Meter Pro
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Zone Tool
Calculate photographic exposure and development adjustments using zone system theory. Measure shadows and highlights, input film ISO and desired shutter speed to determine aperture and development time modifications.
- Zone system exposure calculation
- Shadow and highlight measurement
- Film ISO input
- Shutter speed adjustment
- Development time calculation
- Aperture determination
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With this tool you can calculate your exposure and needed adjustment for development. It uses zone system theory originally invented by Ansel Adams and Fred Archer. First decide zone of your shadows and measure the shadows. Then device highlight zone and measure the highlights. Measure these with the film ISO you are going to use. You also need to decide shutter speed in beforehand. The app calculates exposure aperture for you and also tells if you need to shorten (N+..) or expand (N-..) your development time. You will get best results with a spot light meter but mobile apps will probably do fine.
Spot Meter Pro
This app functions as a professional light meter for film photography, measuring light within a 2° angle of view. It offers customizable settings for aperture, shutter speed, and film speed, along with logging capabilities for readings.
- 2° FOV light metering
- Av and Tv priority modes
- Zone System and Tone Picker metering
- Customizable increments and range
- Log readings
- 1° FOV with telephoto lens
- Meter calibration
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An essential tool for film photography. Designed to function like a real spot meter, Spot Meter Pro measures light within a 2° circular angle of view for accurate exposure value readings. Select your film speed, then adjust aperture or shutter speed for Av or Tv priority. Optionally, adjust the “middle-grey” reading using the Zone System or Tone Picker metering modes to achieve your desired exposure. Additional features: - Customize aperture, shutter speed, and film speed increments and range - Log readings for future reference - iOS devices equipped with a telephoto lens can take a 1° circular angle of view reading - Calibrate the light meter in 1/10th increments - Toggle black & white mode
Screenshots
Verdict
The clearest difference is rating: Spot Meter Pro at 4.5 against Zone Tool's 2.8. Spot Meter Pro also leads on update cadence (every 2 months vs every 38 months) and chart position (#141 vs unranked). Zone Tool's advantage is review sentiment (100% vs 67%) and price ($0.99 vs $4.99). On ads, in-app purchases, monetization model and device support 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
Zone Tool costs $0.99 and Spot Meter Pro $4.99 up front. Neither carries in-app purchases, so what you see is what you pay.
Spot Meter Pro holds the better App Store score, 4.5 against 2.8. Both are backed by a comparable volume of ratings — 6 and 22 respectively. Written reviews complicate that: 100% of Zone Tool's written reviews are positive against 67% of Spot Meter Pro's, so the app with the better star average is not the one people write more warmly about.
Zone Tool ships an update every 38 months, Spot Meter Pro every 2 months. Both last shipped on October 24, 2026.
| Parameter | Zone Tool | Spot Meter Pro |
|---|---|---|
| Price | $0.99 — better | $4.99 |
| Rating | 2.8 (6 ratings) | 4.5 (22 ratings) — better |
| Positive reviews | 100.0% of reviews — better | 66.7% of reviews |
| Number of ratings | 6 | 22 — better |
| Update frequency | Every 38 months | Every 2 months — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Paid |
| Best chart rank | — | #141 — better |
| Devices | iPhone, iPod | iPhone, iPad, iPod — better |
| Requires iOS | 12.2 — better | 14.4 |
| Further details — not scored | ||
| Size | 0 MB | 75 MB |
| Age rating | 4+ | 4+ |
| Developer | Jouni Erola | Tebo Labs Inc. |
Customer experience
Zone Tool
Spot Meter Pro
In-app purchases
Zone Tool
No in-app purchases
Spot Meter Pro
No in-app purchases
Questions
Is Zone Tool free?
Is Spot Meter Pro free?
Which has better reviews, Zone Tool or Spot Meter Pro?
Do Zone Tool or Spot Meter Pro have ads?
Which is updated more often, Zone Tool or Spot Meter Pro?
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