FlashFlashApp
Guide Number. Both Ways.
$9.99 · Designed for iPad. Not verified for macOS.
Set your aperture — get the power. Set the power — get the aperture. The Guide Number formula, solved instantly. Works anywhere you shoot.
Know your flash settings before you shoot — not after three test frames.
FlashFlash is a manual flash calculator built on the Guide Number method. It solves in both directions:
POWER CALCULATOR
Set your aperture. FlashFlash tells you exactly what power fraction to dial in — 1/4, 1/16, whatever the shot needs.
APERTURE RECOMMENDER
Set your power level. FlashFlash tells you exactly which f-stop to use. Battery-constrained, locked into a specific power level, planning a shot before you arrive — this is the tab for it.
No test shots. No chimping. Enter your settings, read the answer, nail the exposure.
WHAT YOU ENTER
· Guide Number — type it manually or pick from 100+ built-in presets (Godox, Canon, Nikon, Sony, Profoto, Elinchrom, and more)
· ISO
· Aperture or power level — depending which tab you're on
· Flash-to-subject distance
· Flash zoom from 24 mm to 200 mm
· Filter compensation for gels, diffusers, and softboxes
WHAT YOU GET
· The exact power fraction or f-stop, snapped to a real standard setting
· Effective GN and Required GN — so you know exactly how much headroom you have
· A live scene visualization: your flash, your subject, your light cone, updating in real time
· A power bar showing at a glance how hard your flash is working
ON CAMERA OR OFF
FlashFlash always asks for flash-to-subject distance — not camera-to-subject. Because when your flash is on a stand three feet from your subject and you are eight feet away, those numbers are not the same. And that difference is everything.
FULLY OFFLINE
No account. No network connection. No subscription. One purchase. Your settings are saved on your device. Works anywhere you shoot.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
UX improvements for smaller screen sizes.
The developer, Egemen Gozoglu, 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
- Egemen Gozoglu
- Size
- 873.5 KB
- Category
- Photo & Video
- Compatibility
Requires iOS 26.2 or later.
- iPhone
Requires iOS 26.2 or later. - iPad
Requires iPadOS 26.2 or later. - Mac
Requires macOS 26.2 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 26.2 or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- Copyright
- © Egemen Gozoglu
