our phone is now the most capable light meter you own.
Deco-Lux Exposure is a professional-grade spot and incident light meter built for photographers who shoot film. Whether you're metering a single shadow with a Leica rangefinder or mapping nine zones across a 4x5 landscape, this is the tool that replaces a $700 handheld meter — and does things no handheld meter can.
PRECISION METERING
• Spot metering via rear camera with hybrid AE analysis for accurate EV readings in any condition
• Average and center-weighted metering modes for quick overall scene evaluation
• Incident metering via ambient light sensor — no accessory dome required
• Adjustable calibration (±3.0 EV in 0.1-stop increments) to match your trusted reference meter
• EV smoothing for stable, readable values without jitter
ZONE SYSTEM — BUILT IN, NOT BOLTED ON
• Full Zone 0–X visualization with true grayscale rendering
• Store up to 9 readings as midtone, shadow, or highlight
• Subject Brightness Range (SBR) calculated automatically
• Drag-to-place zone shifting — slide the entire tonal map to expose for the zone you want
• Pre-visualization strip shows how your readings will actually render on film
• N+/N- development suggestions based on SBR and film characteristics
• Dynamic range clipping warnings when your scene exceeds your film or camera
FILM STOCK INTELLIGENCE
• 30+ built-in film profiles: Tri-X, HP5+, Portra, Ektar, Velvia, and more
• Automatic reciprocity failure correction — no more guessing at long exposures
• Exposure latitude indicators for over and under exposure
• Push/pull limits per stock
EXPOSURE PRIORITY MODES
• Program (P): Best-match aperture and shutter from your camera's actual settings
• Aperture Priority (Av): Lock your f-stop, get the shutter speed
• Shutter Priority (Tv): Lock your shutter, get the aperture
• Tap any exposure combo to see every valid aperture/shutter combination for the scene
CAMERA PROFILES
• Define your camera's exact aperture and shutter speed clicks
• Set dynamic range per body — the app works within your camera's real capabilities
• 7 presets included: Leica M6, Hasselblad 500 C/M, Nikon F3, and more
• Create unlimited custom profiles
SESSION LOGGING
• Automatic session tracking with every metering sequence
• GPS tagging with reverse geocoding — know exactly where you made each exposure
• Review past sessions with full zone bar reconstruction
• Editable notes per session
• Shareable exposure cards — art deco styled 1080×1920 PNG summaries of your metering data
PHOTOGRAPHY TOOLS
• Pinhole Calculator — with film-specific reciprocity correction
• Filter Stack Calculator — ND, polarizer, and B&W contrast filters with 23 presets
• Bellows Extension Calculator — macro and large format compensation
• Depth of Field Calculator — near/far limits, hyperfocal distance, visual depth bar
• Fill Flash Calculator — guide numbers, ratios, sync speed constraints
• Long Exposure Timer — countdown with alarm, vibration, and screen wake lock
• EV Reference Table — real-world scene descriptions from EV -6 to EV 18
DESIGNED FOR THE DARKROOM, NOT THE FEED
• Dark theme with gold and deep purple accents — inspired by art deco instrument design
• Luminance histogram with zone-coded clipping warnings
• Multi-spot map overlay showing all stored readings on the viewfinder
• Voice readout for hands-free operation in the field
• Home screen widget for instant EV/exposure at a glance
• Pinch-to-zoom for precise spot targeting
• AE lock for comparing scene brightness with a frozen reference
• Full landscape support — no state loss on rotation
No ads. No subscriptions. No cloud account. Your data stays on your device.
Made by a photographer, for photographers.
The precision light meter film photographers have been waiting for.