# ShutterFinder: Flicker Meter — Scan light, get shutter speed

> Detects light flicker and recommends optimal shutter speed for flicker-free video. (iPhone/iPad app by Nuncha.)

- Source: https://appshunter.io/ios/app/shutterfinder-flicker-meter/id6760565737 (this page in markdown: same URL + `.md`)
- Developer: [Nuncha](https://appshunter.io/developer/371879216)
- Category: Photo & Video, Utilities
- Price: $2.99
- Rating: 5.00/5 from 1 App Store ratings
- Age rating: 4+
- Requires: iOS 17.0 · 2 MB
- Languages: American English
- Released: 2026-03-20
- Data updated: 2026-10-11
- Monetization: paid
- User reviews in markdown: https://appshunter.io/ios/app/shutterfinder-flicker-meter/id6760565737/reviews.md

## What is ShutterFinder?

Stop guessing your shutter speed on set. Point your iPhone at a flickering light, tap Measure, and ShutterFinder tells you the exact shutter speed that makes the flicker disappear in your footage.

HOW IT WORKS
ShutterFinder films the light at 240 frames per second, finds the flicker frequency with spectral analysis and turns it into a shutter speed for the frame rate you shoot at. It then checks the result at a second frame rate, which unmasks fast LED dimmers that would otherwise look like ordinary mains flicker. Within seconds you know what to set.

WHAT IT MEASURES
• LED panels and practicals, tube lights, HMIs, neon, monitors and TVs
• LED dimmers (PWM) and OLED screens, including many that flicker too fast for the camera to see directly
• 50 Hz and 60 Hz mains, anywhere in the world
• Mixed lighting: when two lights flicker at different rates, the advice takes both into account and shows the alternative

BUILT FOR THE SET
• Shutter as time (1/50) or angle (180°), one tap to switch
• 23.98, 24, 25, 29.97, 30, 50 and 60 fps, plus any custom frame rate
• Change the frame rate after measuring and the advice updates instantly
• When no flicker-free shutter exists at your frame rate, such as some tube lights at 60 fps, ShutterFinder says so and gives the setting that leaves the least flicker
• Honest results: too dark, too shaky or no flicker at all is reported as exactly that, never as a guess
• The circle marks exactly what is measured; tap anywhere to focus
• Measuring stops by itself as soon as the reading is solid

UNDER THE HOOD
• 240 fps high-speed capture with automatic exposure bracketing for dark scenes
• Verification at a second, and when needed a third, frame rate to resolve frequencies above what the camera sees directly
• FFT analysis with Apple's Accelerate framework and sub-Hz precision
• Mains frequencies locked to their exact values, so 100 Hz gives an exact 1/50

PRIVACY
Everything is measured on your iPhone. No images or video are ever stored or sent. Anonymous usage statistics (no personal data, no tracking) help us improve the measurements.

Requires iPhone XS or later with iOS 17 or later.

## Key features

- Detects flicker frequency with precision
- Recommends exact shutter speed or angle
- Supports all common shooting frame rates
- Works with LED, fluorescent, HMI, and monitors
- Uses 240fps slow-motion capture
- FFT spectral analysis for accuracy


## Frequently asked questions about ShutterFinder

### What is ShutterFinder?

ShutterFinder is a tool that detects light flicker from sources like LEDs and fluorescent lights. It then provides the exact shutter speed or angle needed to eliminate this flicker for smoother video footage.

### How does ShutterFinder work?

It uses your iPhone's 240fps high-speed camera and real-time FFT analysis to measure the flicker frequency of light sources. The app then calculates and recommends the optimal shutter speed to avoid flicker.

### What types of lights can ShutterFinder detect flicker from?

ShutterFinder can detect flicker from a wide range of sources including LED panels, fluorescent tubes, HMI lights, monitors, and other practical lights.

### What devices does ShutterFinder support?

ShutterFinder requires an iPhone XS or later running iOS 17.0 or newer. It is designed for the iPhone platform.

### How much does ShutterFinder cost?

ShutterFinder is available for a one-time purchase price of $2.99. There are no in-app purchases or subscription fees associated with the app.

### Is ShutterFinder suitable for beginners?

While built for professionals, ShutterFinder features a one-tap workflow. Simply point at the light source, tap measure, and get your shutter speed, making it accessible.

### How accurate is ShutterFinder's flicker detection?

The app achieves sub-Hz frequency accuracy with parabolic interpolation and uses 240fps slow-motion capture for high-resolution temporal sampling, ensuring precise readings.

### Does ShutterFinder have ads?

No, ShutterFinder is ad-free. As a paid application, it provides an uninterrupted user experience without any advertisements.

## Version history (last 5 releases)

### 1.6 — 2026-10-01

The most accurate ShutterFinder yet, checked in hundreds of simulated measurements at every common frame rate from 23.976 to 60 fps.

New in 1.6:
- Dimmers and screens that flicker between the mains frequencies, at 140 or 200 Hz for example, are read far more reliably. When the frequency can't be pinned down, ShutterFinder now says so instead of guessing
- The screen stays on while measuring, so auto-lock can no longer cut a measurement short
- A scene that is too dark says so in about 9 seconds instead of 35
- 120 Hz lighting at 23.976 fps now gets the familiar 1/60 (144°), the same as at 24 fps
- Weak 120 Hz flicker is picked up more often
- The frame rate row fits on small iPhones, and the result no longer covers the measuring circle
- TIME or DEGREES is remembered, and the alternative for a second light follows your choice
- After a tap to focus, autofocus takes over again when you reframe
- Custom frame rate: the keyboard opens right away and a value that can't be used is marked
- When another app or heat takes the camera away, ShutterFinder says so instead of showing a frozen image

And since 1.5:
- Finds LED dimmers and OLED screens that flicker faster than the camera can see directly, like 240, 480, 960 or 1200 Hz, and names the right frequency
- Two lights at once, like a monitor next to a lamp, are recognised, and the advice takes both into account
- LED dimmers at uneven frequencies, like 297 or 596 Hz, are now read correctly
- US mains lighting (120 Hz) is pinned exactly, so you get 1/60 instead of 1/59
- Tube lights and LED drivers with a hidden 50 Hz flicker are recognised reliably and get a safe shutter, also at 59.94 and 60 fps
- A bright scene without flicker gets its verdict in about 12 seconds instead of 40
- ShutterFinder now measures exactly what is inside the circle, so a lamp just outside it can't spoil the reading
- A camera hiccup or an interrupted measurement no longer leads to a wrong result
- Devices that can't film at 240 fps now tell you so, instead of reporting no flicker

Anonymous usage statistics (no personal data, no tracking) help us keep improving the measurements.

### 1.5 — 2026-09-30

The most accurate ShutterFinder yet, checked in hundreds of simulated measurements at every common frame rate from 23.976 to 60 fps.

- Finds LED dimmers and OLED screens that flicker faster than the camera can see directly, like 240, 480, 960 or 1200 Hz, and names the right frequency
- Two lights at once, like a monitor next to a lamp, are recognised, and the advice takes both into account
- LED dimmers at uneven frequencies, like 297 or 596 Hz, are now read correctly
- US mains lighting (120 Hz) is pinned exactly, so you get 1/60 instead of 1/59
- Tube lights and LED drivers with a hidden 50 Hz flicker are recognised reliably and get a safe shutter, also at 59.94 and 60 fps
- A bright scene without flicker gets its verdict in about 12 seconds instead of 40
- ShutterFinder now measures exactly what is inside the circle, so a lamp just outside it can't spoil the reading
- A camera hiccup or an interrupted measurement no longer leads to a wrong result
- Devices that can't film at 240 fps now tell you so, instead of reporting no flicker

Anonymous usage statistics (no personal data, no tracking) help us keep improving the measurements.

### 1.4 — 2026-06-10

Bug fixes

### 1.3 — 2026-06-01

UI updates

### 1.2 — 2026-03-20

Improved shutter detection.

## Apps similar to ShutterFinder

| App | Rating | Price | Category |
| --- | --- | --- | --- |
| [FlickerMeter Pro: Film & Video](https://appshunter.io/ios/app/flickermeter-pro-film-and-video/id6803379315) | — | Free | Photo & Video |
| [Flicker Safe: Test Light](https://appshunter.io/ios/app/flicker-safe-test-light/id6771406035) | — | Free | Photo & Video |
| [Fast Release - Model Releases](https://appshunter.io/ios/app/fast-release-model-releases/id6748971459) | 5.0 (1) | $4.99 | Photo & Video |
| [Timelapse Maestro](https://appshunter.io/ios/app/timelapse-maestro/id6790658807) | 5.0 (2) | Free | Photo & Video |
| [Pontus Viewfinder](https://appshunter.io/ios/app/pontus-viewfinder/id6764829581) | — | $12.99 | Photo & Video |
| [FlickerFinder](https://appshunter.io/ios/app/flickerfinder/id1495117202) | 1.0 (1) | $29.99 | Photo & Video |

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All apps by Nuncha: https://appshunter.io/developer/371879216

## Related topics

[flicker meter](https://appshunter.io/ios/topics/flicker-meter)

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-10-11.*