Halation

Add Exif metadata to film photographs.

Installation

Halation is available as a Ruby gem.

  1. Install Ruby 2.1 or higher.

  2. Install ExifTool.

  3. Open the command line and type:

gem install halation

Configuration

Halation stores its global configuration data in .halation in the system's user directory. This is typically ~/.halation on Mac and *nix-based systems, or C:\Users\.halation on Windows.

Halation uses the YAML syntax for its configuration files.

By default Halation uses a global configuration file, ~/.halation/config.yml. This is where your generic settings are stored, like your name, copyright info, and information about your cameras.

# Example config.yml
---
artist: "Example User"
copyright: "2016 Example User"
cameras:
  - tag: "rz67"
    make: "Mamiya"
    model: "Mamiya RZ67 Pro II"
    lenses:
      - tag: 65
        model: "M65mm f/4L-A"
        focal_length: 65
      - tag: 110
        model: "Z110mm f/2.8W"
        focal_length: 110
      - tag: 180
        model: "Z180mm f/4.5W-N"
        focal_length: 180
      - tag: 250
        model: "Z250mm f/4.5W"
        focal_length: 250

Tags

Tags are user-defined values that serve as a quick and simple way to reference complex information.

Why is this important? Let's say you shot a roll of ten images with several different lenses. It would be cumbersome to have to specify a model number like Z110mm f/2.8W (and all the other lens information) on each of the frames. Even more importantly, if you're processing batches of images over a long period of time (months, years), you're bound to make mistakes in the spelling of the model number. This is important because any software that catalogs images based on Exif data (Lightroom, Flickr) doesn't know how to deal with these inconsistencies. This means Z110mm f/2.8W and Z110mm f/2.8 W will be considered two different lenses by the software (did you see the difference?), even though we as humans understand they're the same thing. If you try to filter by lens in Lightroom, some of the images will be under one spelling and some will be under the other, even though they were both shot with the same 110mm lens.

Tags solve this problem by letting us define all of the complex, infrequently-changing data in one place. We can then reference that complex data by its tag. For example, if we have a 65mm lens and a 110mm lens we can define their information once and tag them as 65 and 110 respectively (we choose the tag names).

lenses:
  - tag: 65
    model: "M65mm f/4L-A"
    focal_length: 65
  - tag: 110
    model: "Z110mm f/2.8W"
    focal_length: 110

Now when we want to reference which lens was used when capturing a particular frame, all we have to do is specify the tag and Halation will fill in the correct Exif data for that lens when the image file is processed.

frames:
  - number: 1
    lens: 110
  - number: 2
    lens: 65
  - number: 3
    lens: 110

Processing A Roll

Halation requires all of the image files for a roll of film to be in the same directory. The images should be named in ascending alphabetical order, with the first frame of the roll at the start of the list and the last frame at the end. This is typically the default when scanners save files. Halation will scan for tiff files (.tif, .tiff), which is the ideal format, as well as jpeg files (.jpg, .jpeg).

This directory should also contain a roll.yml file, which specifies the data for each frame (image file) on the roll of film. A new roll.yml file can be generated in the current directory with the following command:

halation --new-roll

The data for the roll can then be entered into the file:

# Example roll.yml
---
date: "2016-01-01"
camera: "rz67"
lens: 110
iso: 100
frames:
  - number: 1
    shutter: "1/125"
    aperture: 8
  - number: 2
    shutter: "2"
    lens: 65
    aperture: 16
  - number: 3
    lens: 65
    shutter: "0.5"
    aperture: 16
  - number: 4
    lens: 65
    shutter: "0.5"
    aperture: 16
  - number: 5
    shutter: "1/250"
    aperture: 4
  - number: 6
    shutter: "1/125"
    aperture: 8
  - number: 7
    shutter: "1/125"
    aperture: 8
  - number: 8
    shutter: "1/60"
    aperture: 22
  - number: 9
    date: "2016-01-02"
    shutter: "1/400"
    aperture: 8
    flash: yes
  - number: 10
    date: "2016-01-02"
    shutter: "1/400"
    aperture: 8
    flash: yes

Default values can be set at the beginning of the file so that these settings don't have to be specified for each frame. For example, the roll of film has one ISO speed for all of the frames, so this can be specified at the top instead of for each individual frame.

Values like the date are a little different, because maybe the whole roll was shot during the same day, or maybe it was shot over the course of several days. This is where the roll.yml file provides flexibility. Specifying date at the beginning of the file will make it the default date for all of the frames on the roll. If not all of the frames were shot on the same day, date can then be specified for each of the frames that have a different date (9 and 10 in the example above). This concept works for most of the values.

A complete list of keywords are available in the Halation API documentation, as well as in the sample files.

After all of the necessary values are entered into roll.yml, the images can be processed by running the following command:

halation