CyanHero

A professional macOS app for converting images into negatives for cyanotype printing, featuring a dark theme interface inspired by modern photo editing tools.

Features

Image Processing

• Grayscale Conversion - Automatic conversion to monochrome
• Negative Inversion - Creates proper negatives for UV exposure
• Contrast Control (0.5 - 2.5) - Adjust tonal separation
• Brightness Control (-0.5 - 0.5) - Fine-tune overall density
• Scale Adjustment (10% - 1000%) - Resize your image
• Gradient Curves - Professional tone curve adjustments
  • Load Photoshop .acv curve files
  • Preset curves for different alternative processes (Cyanotype, Van Dyke, Platinum, etc.)
  • Save custom curves for reuse

Transform Tools

• Rotate - 90° increments left or right
• Flip - Horizontal and vertical mirroring
• Crop - Select and crop to specific area
• Undo Crop - Restore the image before the last crop

Preview Modes

• Negative Preview (B&W) - Default view showing the actual negative
• Cyanotype Preview (Blue) - See how your print will look with the characteristic Prussian blue color
  • Click the droplet icon to toggle between modes

Histogram

• RGB Channels - View red, green, and blue channel distribution
• Luminance - See overall brightness distribution
• Channel Toggles - Show/hide individual channels for detailed analysis
• Real-time Updates - Histogram updates as you adjust image settings

UV Index Tool

• Real-time UV Data - Check current UV levels for planning exposures
• UV Forecast - View hourly UV predictions throughout the day
• 100+ Cities - Search or select from preset worldwide locations
• GPS Support - Use your current location automatically
• Sun Times - Sunrise, solar noon, sunset, and twilight times
• Safe Exposure Guide - Recommended sun exposure limits by skin type

Professional Interface

• Dark Theme - Easy on the eyes during long editing sessions
• Icon-Based Toolbar - Quick access to all tools
• Side Panel Controls - Real-time adjustment sliders with value displays
• Drag & Drop Support - Drop images directly onto the canvas

How to Use

1. Import an Image

   • Click the Import button (down arrow) in the toolbar
   • Or drag and drop an image onto the canvas

2. Adjust Your Image

   • Use the sliders in the left panel to adjust brightness, contrast, and scale
   • Scale slider - Resize the image from 10% to 1000%
   • Gradient Curves - Select from preset curves or load custom .acv files
     • Click the dropdown menu under "CURVES"
     • Choose from presets like Cyanotype, Van Dyke, Platinum, etc.
     • Load your own .acv curve files
     • Save modified curves for later use
   • Use toolbar buttons to rotate or flip the image
   • Click the crop tool, drag to select an area, then click "Apply Crop"
   • Use the undo button (↶) to restore the image before cropping

3. Preview

   • Click the droplet icon to toggle between negative (B&W) and cyanotype preview (blue)
   • The preview shows approximately how your final print will look

4. Print & Export

   • Click the Print button to print directly to your printer
     • Configure page size (Letter, A4, Legal, Tabloid)
     • Toggle between Portrait and Landscape orientation
     • Set up multi-page printing using the Pages button
     • Position and scale your image on the page
   • Or click the Export button (up arrow) to save as PNG, JPEG, or TIFF
   • Print on transparency film or display on a screen/tablet for exposure

Cyanotype Workflow

1. Convert your image to a negative using CyanHero
2. Print the negative on acetate/transparency film
3. Place the negative on UV-sensitive cyanotype paper
4. Expose to sunlight or UV light
5. Develop in water to reveal the classic Prussian blue print

System Requirements

• macOS 14.0 or later
• Xcode 15.0 or later (for building from source)

Building

open CyanHero.xcodeproj
# Press Cmd+R to build and run

License

Created for cyanotype enthusiasts and alternative process photographers.