BoltRatio Flash Lab

BoltRatio Flash Lab is an offline-first studio flash workbench for portrait, product, and event photographers who need reliable guide-number math and multi-light power ratios—without spreadsheets or guesswork.

Turn flash guide numbers, stop ratios, and modifier loss into a polished on-device lighting bench so you leave for a shoot with exact power, distance, and a shareable diagram.

GET STARTED FAST
Complete onboarding teaches guide numbers, power fractions, and stop ratios, then drops you into three seeded demo scenes—softbox portrait, two-light product, and gelled rim—ready to edit. No empty states or placeholders.

GEAR BAY
Browse and edit common speedlights, studio monolights, and pack heads with reference guide numbers, zoom slots, and min/max power steps. Add custom heads with your own GN and power ladder.

CAMERA STRIP
Lock a working camera body label, ISO, target aperture, and shutter ceiling. Reuse it across solvers so every distance and power answer stays consistent for the session.

SINGLE-SOURCE SOLVER
Enter subject distance or desired f-stop and instantly get required power fraction, effective GN, and reciprocal answers. Flip units between feet and meters with live recalculation.

MULTI-LIGHT RATIO BOARD
Place key, fill, hair, and rim on a visual board. Drag role chips, set stop offsets from key, and read absolute power suggestions per head with live ratio badges (for example, key 1/4, fill −1.5 stops).

MODIFIERS & BOUNCE
Apply light-loss from a seeded palette—softbox, shoot-through umbrella, reflective umbrella, beauty dish, grid, CTO/CTB gel, ceiling bounce—or set custom loss in tenths of a stop.

INVERSE-SQUARE PLAYGROUND
Drag subject and wall markers on a scaled floor plan, preview stop falloff to the background, and pin safe working distances before you move stands.

SCENES & EXPORT
Save named lighting scenes linking gear, camera strip, ratios, distances, and notes. Duplicate a scene for location versus studio variants and open any scene straight into the board or solver. Export a shareable lighting diagram (image + PDF) via the system Share Sheet with roles, powers, distances, modifiers, and aperture/ISO—end-to-end offline.

WIDGETS & SHORTCUTS
Install WidgetKit glance cards for the active scene’s power cheat-sheet and a quick GN↔distance converter. Use the App Intent “Solve flash distance” with Shortcuts. Settings include units, appearance, Dynamic Type-friendly text, and a full in-app Privacy Policy.

PRIVACY BY DESIGN
Fully on-device with SwiftData. Seeded pro gear and demo scenes. No account and no network required.

Leave napkin math behind. Walk into every shoot with exact flash power, distance, and a clean lighting diagram.