Flash Power
Perfect Exposure Made Easy
Only for iPhone
Free · In‑App Purchases · Designed for iPhone
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, but compatible with any manual flash. You can also create a custom flash profile by entering your flash’s guide number and zoom behaviour.
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, with ⅓-stop precision.
FEATURES
• Distance measurement with LiDAR, ARKit surface detection, or manual entry
• Preconfigured flash profiles for Camtraptions F1, Z1/Z2, and Z Pro
• Custom guide number support for any manual flash
• Zoom head compensation from 20mm to 200mm
• Coverage preview to visualise flash spread
• 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.
Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Ratings & Reviews
This app hasn’t received enough ratings or reviews to display an overview.
• Improved accuracy of flash power algorithm and zoom coverage.
• Enhanced support for other flashes.
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.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- WILLIAM BENJAMIN BURRARD-LUCAS
- Size
- 1.5 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+
- 4+
- In-App Purchases
Yes
- Subscriber $4.99
- Copyright
- © 2026 Will Burrard-Lucas