Lumen Forge
Field exposure meter
$3.99 · Designed for iPad. Not verified for macOS.
Now with Field Pack: live shot briefs, readiness scoring, and ten offline reference sheets for exposure, lighting, ND, gels, macro, cinema, and film.
Lumen Forge is a field exposure workbench for photographers, cinematographers, gaffers, students, and anyone who wants reliable light and exposure math close at hand.
Use the camera-based meter to read scene luminance and color temperature, then move directly into exposure planning, ND selection, flash guide-number math, zone-system notes, saved lighting recipes, or the new Field Pack.
Core tools:
- Live camera-based light meter
- Lux, foot-candle, EV, ISO, shutter, and aperture readouts
- Exposure triangle solver with equivalent exposure ladders
- Color-temperature reference swatches for common lighting conditions
- Zone-system histogram with shadow and highlight warnings
- ND filter calculator for daylight long-exposure planning
- Flash guide-number math with ISO scaling
- Lighting recipe notebook with modifier, subject, and location notes
- Side-by-side recipe compare
- B&W filter factor calculator with Kelvin interpolation
- Hyperfocal, cine shutter, sunny f/16, macro, polarizer, and star-trail helpers
- Film reciprocity correction and AEB bracketing planner
- Field Pack with readiness scoring, support/gels/ND/bracket guidance, copyable shot brief, and ten offline reference sheets
Lumen Forge keeps the workflow focused: meter the light, compare choices, save a useful note, and get back to shooting.
Lighting recipes and app settings stay on the device. Camera access is used only for the live meter and color-temperature features.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
Version 2.1 adds Field Pack: a shot-brief planner with readiness scoring, ND/gels/bracket/support recommendations, copyable production notes, and ten high-resolution offline reference sheets for exposure, lighting ratios, Zone System placement, ND, gels and mired correction, cinema shutter angle, macro bellows, film reciprocity, location scouting, and keeper-frame prep.
Also includes updated screenshots and metadata to show the current app UI and Field Pack workflow.
The developer, Robert Corbin, 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
- Robert Corbin
- Size
- 28.1 MB
- Category
- Photo & Video
- Compatibility
Requires iOS 17.0 or later.
- iPhone
Requires iOS 17.0 or later. - iPad
Requires iPadOS 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.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- Copyright
- © 2026 Robert Corbin

