Lumis

Light, Precisely.

Lumis — darkroom enlarger spot meter

A precision metering system for the darkroom enlarger. Powered by ESP32, with a TSL2591 high-dynamic-range light sensor and a BLE companion app.

Spot Metering

Measure up to 8 spots across the projected image

Zone System

Assign each spot to Zones 0–X for precise tonal placement

Exposure Calculation

Automatic exposure time based on paper calibration curves

Split-Grade Printing

Calculates Grade 00 (soft) and Grade 5 (hard) exposure times

Dry-Down Compensation

Highlight-weighted sigmoid correction

16 Paper Profiles

10 factory presets + 6 user-defined

App

Real-time monitoring and remote control via Bluetooth. Zone Map visualization and f-stop fine-tuning.

Design

Enclosure designed in Fusion 360, 3D printed.


Interested? Reach out at cllee112@gmail.com