Field exposure meter

Lumen Forge

Field exposure meter

Lumen Forge is a field exposure workbench for photographers, cinematographers, gaffers, students, and anyone who wants reliable light and exposure math close at hand.

iPhone & iPadNo accountNo ads or trackingPrivate by design

Features

What it does

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

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:

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.

Privacy

Private by design

Lumen Forge does not require an account and does not include third-party advertising or analytics SDKs. Content you create stays in the app on your device unless you explicitly export or share it. See the privacy policy.