🧪 DarkroomPro

A professional desktop application for calculating precise film development parameters with scientifically accurate timing, temperature compensation, and published push/pull data for 433 film/developer combinations.

📸 App Preview

Main window: film/developer selection, process controls (kit temperature lock, batch reuse, agitation method), calculation results, the timer with custom agitation, and the sourced film/developer information panels.

Darkroom mode's fullscreen focus display, toggled with F or the Auto Fullscreen option.

🆕 What's new in 1.3.2

Dilution ratio and volume input removed: the ratio is printed on the developer bottle and named in the developer selector, so the app no longer repeats it or asks for a tank volume. Tank volume does not change development time, so there is nothing to calculate.
Kit mixing and capacities: every colour kit now shows its actual kit mixing and capacity, including Bellini C41-RA (500 ml concentrate + 500 ml water = 1 L, 16 rolls) and Kodak Flexicolor (2.5 L, 20 rolls one-shot).
Better agitation chimes: ticks now repeat every ~1.1s at a clearly audible level, with a distinct two-tone stop cue when the agitation window ends. The scheduler ensures only one sequence plays at a time.
Timer cleanup fix: pausing or resetting now immediately clears the pulsing orange agitation dot, the “Agitate now” text, and the completion flash instead of leaving them running.
Kodak E-6 +2 push corrected to 11:30 rotary / 11:45 manual (+5:30 per Kodak Z-119).
Includes 1.3.1’s adjustable B&W rotary compensation and E-6 method-specific timing.

See RELEASE_NOTES.md for the full changelog.

🎯 Key Features

47 Film Stocks - Comprehensive database of B&W, color negative, and slide films
18 Developers - Popular developers with precise dilution ratios
433 Combinations - Sourced film/developer pairings with provenance
Temperature Compensation - Per-developer curves sourced from manufacturer charts (15-30°C)
Push/Pull Processing - +3 push and -2 pull stops where published; B&W uses the documented Massive Dev Chart guideline when a row is missing
Agitation Method - Intermittent or rotary/continuous; rotary uses an adjustable 0-35% B&W developer-time reduction (15% default, starting point)
Multi-Step Timer - Auto, Buffer and Manual step transitions with a customizable step editor
Agitation Reminders - Published schedules or your own interval/duration, with optional repeating chimes during each agitation window
Batch Reuse Compensation - Track rolls already developed through a batch; applies the kit's published compensation (CineStill, Tetenal, Bellini) where one exists
Darkroom Mode - Safelight theme plus wake-lock and fullscreen options in one toggle; the fullscreen focus display opens when the timer starts (Auto Fullscreen option) or with the F key
Built-in Timer - Integrated countdown with audio alerts
Export Functionality - Save calculations as JSON, CSV, or PDF
Cross-Platform - Native apps for macOS, Windows, and Linux

✨ Features

📊 Comprehensive Database

47 Film Stocks: Complete database of B&W, color negative, and slide films
18 Developers: Popular developers with precise dilution ratios
433 Combinations: Sourced film/developer pairings with provenance
Manufacturer Grouping: Films organized by brand for easy selection

🧮 Advanced Calculations

Temperature Compensation: Per-developer curves for B&W developers from Kodak and Ilford charts, with a standard conversion fallback where no manufacturer chart exists. Colour kits are locked to the kit's standard temperature; kits that publish a temperature table can be unlocked explicitly
Agitation Method: Intermittent (inversion) or rotary/continuous. For black & white, rotary processing uses an adjustable 0-35% reduction (15% default; 15-35% may be needed depending on film/developer, and pre-wetting or a diffusion enlarger can need less). E-6 first-developer times switch between the published manual and rotary values; C-41 uses the kit time
Push/Pull Processing: +3 push and -2 pull stops. B&W falls back to the documented Massive Dev Chart guideline when no EI row exists; colour push/pull is offered only where the kit publishes a time (no estimated values)
Published Dilution Data: each developer's published dilution is listed in its info panel; pick the matching one in the selector
Type-Safe Calculations: Rust-powered calculation engine for guaranteed accuracy

⏱️ Professional Timer

Multi-Step Process Timer: The developer step is timed from the calculation; add your own bleach, blix, fixer, stabilizer or rinse steps and enter their times from your kit instructions
Transition Modes: Auto-advance, Buffer (custom 1-60s prep window) or Manual start
Agitation Reminders: Cue chimes and on-screen prompts from each combination's published schedule
Custom Agitation: Override the schedule with your own initial agitation (30s by default), interval and duration (for example: 30s at the start, then 10s every 60s); a clear repeating tick plays during each agitation window, with a distinct stop cue
Batch Reuse Compensation: Enter the number of rolls already developed in the batch; the app applies only documented rules - CineStill +2% per roll, Tetenal +15s per 4 rolls at 38°C (60s at 30°C), Bellini +15s per 3 rolls. One-shot developers show no roll-count compensation
Step Editor: Add, reorder, remove or retime steps per film/developer; times are saved automatically
Darkroom Mode: One toggle for the red safelight theme, wake-lock and fullscreen options. The fullscreen focus display opens when you start the timer (Auto Fullscreen on) or press F at any time
Audio Alerts: Step changes, agitation cues and completion tones (agitation chimes can be switched off)

📤 Export & Sharing

Multiple Formats: Export calculations as JSON, CSV, or PDF reports
Timestamped Reports: Professional calculation summaries
Consistent Filenames: Exports are saved as darkroom-calculation-<timestamp>.<format>

🖥️ Cross-Platform

Desktop Apps: Native installers for Windows, macOS, and Linux
Web Build: Optional browser build (served from dist/) for desktop-free use
Responsive Design: Optimized for desktop and tablet use

🏗️ Architecture

Hybrid Rust-JavaScript Design

Rust Backend: Type-safe calculation engine with comprehensive error handling
JavaScript Frontend: Responsive UI with smooth interactions
Smart Bridge: Automatic detection of desktop vs web environment
Graceful Fallback: Uses Rust when available, JavaScript otherwise

Tech Stack

Frontend: Vanilla JavaScript, HTML5, CSS3 with Inter font
Backend: Rust with Tauri framework
Database: Structured JSON with comprehensive validation
Calculations: Decimal precision arithmetic for accurate results
Build System: Cargo + Tauri for cross-platform compilation

📥 Installation

Desktop Apps (Recommended)

Note: Release builds are unsigned. On macOS, right-click the app and choose Open the first time you launch it; on Windows, SmartScreen may ask you to confirm.

Filenames below show the 1.3.2 release; if a newer version is out, grab the matching file from Releases.

macOS

Download DarkroomPro_1.3.2_universal.dmg from Releases
Open the DMG file
Drag DarkroomPro to Applications folder
Launch from Applications or Launchpad

Windows

Download DarkroomPro_1.3.2_x64_en-US.msi from Releases
Run the installer
Follow installation wizard
Launch from Start Menu or Desktop

Linux

Download DarkroomPro_1.3.2_amd64.deb (Debian/Ubuntu), DarkroomPro-1.3.2-1.x86_64.rpm (RedHat/Fedora), or DarkroomPro_1.3.2_amd64.AppImage (portable)

Install using your package manager:

# Debian/Ubuntu
sudo dpkg -i DarkroomPro_1.3.2_amd64.deb

# RedHat/Fedora
sudo rpm -i DarkroomPro-1.3.2-1.x86_64.rpm

Launch from applications menu

🚀 Quick Start

Select your film stock from the categorized dropdown
Choose your developer (filtered based on film compatibility)
Set your temperature (B&W: 15-30°C with automatic compensation; colour kits are locked to their standard temperature — Tetenal 38°C, Unicolor 38.9°C, CineStill 39°C — with an opt-in temperature table only where the kit instructions publish one)
Adjust push/pull if needed (+3 push to -2 pull; unsupported colour combinations are marked “not published”)
Choose the agitation method (intermittent or rotary; adjust the rotary % if needed)
Calculate and get the development time
Start the timer and develop with confidence!
Export results for your records

🛠️ Development

Prerequisites

Node.js 18+ - JavaScript runtime
Rust 1.77.2+ - For Tauri 2 backend compilation
Platform-specific tools:
- macOS: Xcode Command Line Tools
- Windows: Microsoft C++ Build Tools
- Linux: build-essential, libwebkit2gtk-4.1-dev, libssl-dev

Setup

# Clone repository
git clone https://github.com/Panolix/DarkroomPro.git
cd DarkroomPro

# Install dependencies
npm install

# Install Rust (if not already installed)
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

Development Commands

Web Development

# Start the Vite dev server (serves the frontend with hot reload)
npm run dev
# Serves the frontend at http://localhost:1420

npm run web:dev starts a plain python -m http.server 8000 over the raw source files. The browser cannot resolve the bare jspdf import in rust-bridge.js, so use npm run dev for development, or npm run build and serve dist/ for a browser build.

Desktop Development

# Start desktop app in development mode
npm run tauri:dev
# Hot-reloads both frontend and backend

Building

# Build web version
npm run build

# Build desktop app for current platform
npm run tauri:build

# Build for specific platform (cross-compilation)
npm run tauri:build -- --target x86_64-pc-windows-msvc

Project Structure

DarkroomPro/
├── src-tauri/           # Rust backend
│   ├── src/
│   │   ├── main.rs      # Tauri app entry point
│   │   ├── models.rs    # Data structures
│   │   ├── calculator.rs # Calculation engine
│   │   ├── database.rs  # Database management
│   │   └── export.rs    # Export functionality
│   ├── Cargo.toml       # Rust dependencies
│   └── tauri.conf.json  # Tauri configuration
├── dist/                # Built web assets
├── *.js                 # Frontend JavaScript
├── *.css                # Styling
├── *.html               # HTML templates
└── complete_database.json # Film/developer database

🧪 Database

The application includes a comprehensive database of film stocks and developers:

Film Stocks (47)

Black & White: Kodak Tri-X, Ilford HP5+, Fujifilm Acros, etc.
Color Negative: Kodak Portra, Fujifilm Pro 400H, Cinestill 800T, etc.
Slide Film: Kodak Ektachrome, Fujifilm Velvia, Provia, etc.

Developers (18)

B&W: D-76, HC-110, Rodinal, Xtol, etc.
Color: C-41 kits, E-6 kits
Specialized: Push/pull optimized formulations

Data Provenance

Every film/developer combination carries a source, source_url, and verified_date field. Black & white base times and push/pull values are researched from the Massive Dev Chart (which aggregates manufacturer-published times and curated user data); where a combination was re-sourced, the source_url points at the exact chart query used. Where a manufacturer datasheet time was also checked against the chart, the source names both (for example Kodak F-4043 + Massive Dev Chart) and the URL is the chart query. Push/pull values are taken from the chart's published exposure-index rows for that film/dilution; when no reliable row exists the field is left empty and the app falls back to the Massive Dev Chart push guideline (separate factors for standard developers, compensating developers and T-Max films), so no values are fabricated. Colour (C-41/E-6) push and pull times are included only where the kit publishes them; if a value is missing the app says so instead of estimating one.

Batch reuse is applied only where the kit publishes a rule, stored alongside the developer: CineStill CS41 (+2% per roll already developed, 1 L standard solution), Tetenal Colortec C-41 (+15s per 4-roll block at 38°C, +60s at 30°C) and Bellini C41-RA (+15s per 3-roll block). One-shot and replenished developers show no roll-count compensation rather than a guessed value. The database is validated by automated tests (cargo test) that check key resolution, source coverage, and time monotonicity.

🤝 Contributing

Fork the repository
Create a feature branch (git checkout -b feature/amazing-feature)
Commit your changes (git commit -m 'Add amazing feature')
Push to the branch (git push origin feature/amazing-feature)
Open a Pull Request

Adding Film/Developer Data

Edit complete_database.json with new entries
Follow existing data structure
Include accurate development times and dilutions
Test with the application before submitting

📄 License

This project is licensed under CC BY-NC-SA 4.0 - free for personal and educational use. Commercial use requires permission.

👨‍💻 Author

Panagiotis Smponias

🙏 Acknowledgments

Film development data compiled from the Massive Dev Chart, manufacturer specifications (Kodak, Ilford, Fujifilm technical publications), the Film Photography Project, and community darkroom testing
Community testing and feedback from analog photography enthusiasts
Built with Tauri - Rust-powered desktop apps
UI styled with Inter font family, bundled with the app under the SIL Open Font License

Perfect companion for analog photographers seeking precision in their darkroom workflow.

Name		Name	Last commit message	Last commit date
.github		.github
Readme-Images		Readme-Images
public		public
scripts		scripts
src-tauri		src-tauri
.gitattributes		.gitattributes
.gitignore		.gitignore
LICENSE		LICENSE
README.md		README.md
RELEASE_NOTES.md		RELEASE_NOTES.md
calculator.js		calculator.js
complete_database.json		complete_database.json
data.js		data.js
index.html		index.html
package-lock.json		package-lock.json
package.json		package.json
rust-bridge.js		rust-bridge.js
steps.js		steps.js
styles.css		styles.css
timer.js		timer.js
vite.config.js		vite.config.js

Latest commit

History

Folders and files

Repository files navigation