Flash Power

Perfect Exposure Made Easy

Only for iPhone

Free · In‑App Purchases · Designed for iPhone. Not verified for macOS.

iPhone

Stop guessing flash power. Point, measure, and get the exact setting for perfect exposures every time. Get the right flash power setting every time. Flash Power measures the distance from flash to subject, then calculates the precise power setting for a well-exposed shot. THE PROBLEM You are setting up a camera trap in daylight, so you cannot preview flash exposure against the ambient light. You need a way to calculate the correct flash power for a nighttime shot without returning after dark to take test exposures. THE SOLUTION Flash Power gives you a fast, practical way to calculate flash exposure. Use the app to automatically measure the distance from flash to subject, or enter it manually, then set your aperture and ISO. The app calculates the flash power you need, so you can set up with confidence and avoid trial and error after dark. WORKS WITH ANY MANUAL FLASH Preconfigured for Camtraptions F1, Z1/Z2, and Z Pro, and ready for anything else you own. Build your own flash profiles and keep them: name each one, choose a fixed or zoomable head, pick ⅓-stop or ½-stop increments, and set the guide numbers. For a zoom head you set the guide number at each end of the range and the app works out everything in between — pin any focal length you have measured yourself and it stays put. WORKS ON ALL IPHONES • LiDAR-equipped iPhones (Pro models) — instant, accurate distance measurement • Other iPhones — ARKit surface detection, plus manual distance entry • No LiDAR? No problem — measure separately and enter the distance manually BUILT FOR CAMERA TRAPPERS Designed for wildlife photographers using off-camera flash. No more test shots, no more guesswork, and no more blown highlights or underexposed subjects. HOW IT WORKS 1. Hold your phone next to your flash and point it at your subject 2. The app measures the distance, or you enter it manually 3. Set your camera's aperture and ISO 4. Read the recommended flash power The app tells you exactly what power to dial in, from full power down to 1/128, in the same ⅓-stop steps your flash shows — or ½-stops, if that is what your flash uses. CALIBRATE TO YOUR OWN GEAR If your test shots come out consistently over- or under-exposed, dial in a fine-tune adjustment and the app applies it to every calculation from then on. Each flash keeps its own calibration, so a correction measured on one never follows you to another. FEATURES • Distance measurement with LiDAR, ARKit surface detection, or manual entry • Preconfigured flash profiles for Camtraptions F1, Z1/Z2, and Z Pro • Saved custom flash profiles — as many as you need, each with its own name and guide numbers • Per-flash fine-tune calibration • Zoom head compensation from 20mm to 200mm, or whatever range you define • Coverage preview to visualise flash spread • Range reference — maximum distance at full power across common apertures • Real-time calculation as you adjust settings THE SCIENCE Flash Power uses the guide number formula and inverse square law to calculate exposure. It takes aperture, ISO, flash zoom position, and distance into account, then gives you a precise power recommendation to get you close on the first shot. REQUIREMENTS • iOS 17 or later • LiDAR recommended for the best experience (iPhone 12 Pro and later Pro models) Ideal for camera trap setups, macro photography, studio work, and any situation where you need consistent, repeatable flash exposure. SUBSCRIPTION Flash Power is £4.99 per year, starting with a 2-week free trial. Payment is charged to your Apple Account on confirmation of purchase. The subscription renews automatically unless cancelled at least 24 hours before the end of the current period; manage or cancel it in your Apple Account settings. Any unused portion of a free trial is forfeited when you purchase a subscription. Privacy Policy: https://www.camtraptions.com/flash-power-app/ Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

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Saved flash profiles. You can now keep a library of flashes instead of reconfiguring one custom slot every time you switch. Create as many as you need, name them, and pick between them in Settings. • Save any number of custom flashes, each under its own name • Fixed or zoomable head, ⅓-stop or ½-stop increments • Set the guide number at each end of the zoom range and the app fills in everything between — pin any focal length you have measured yourself and it stays put • Duplicate a profile to use one flash as the starting point for another Calibration is now per flash. Your fine-tune adjustment stays with the flash you measured it on, rather than following you to whichever flash you select next. Your existing calibration carries over when you upgrade. Also in this release: • The power reading holds steady on grass, foliage and other awkward surfaces instead of flickering between neighbouring settings • Your zoom position is remembered between sessions — a Z Pro left at 200mm no longer comes back at 20mm • Aperture and ISO are remembered too • The coverage circle is hidden for flashes with no zoom data, rather than drawing a spread the app cannot actually know • Lower battery and heat use while measuring

Version 1.4

The developer, WILLIAM BENJAMIN BURRARD-LUCAS, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .

  • Data Not Collected

    The developer does not collect any data from this app.

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    Accessibility

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    Information

    Seller
    • WILLIAM BENJAMIN BURRARD-LUCAS
    Size
    • 1.7 MB
    Category
    • Photo & Video
    Compatibility
    Requires iOS 17.0 or later.
    • iPhone
      Requires iOS 17.0 or later.
    • Mac
      Requires macOS 14.0 or later and a Mac with Apple M1 chip or later.
    • Apple Vision
      Requires visionOS 1.0 or later.
    Languages
    • English
    Age Rating
    4+
    In-App Purchases
    Yes
    Copyright
    • © 2026 Will Burrard-Lucas
  • Developer Website
  • Privacy Policy

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