Flash Power

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/