ExiFilm: add film exposure metadata to EXIF tags of digital images

I just published ExiFilm, a suite of programs that I use with my large format film workflow, under the GPLv3.


When I'm shooting in the field I carry around a notepad of exposure record forms where I record subject information, luminosity, camera geometry, exposure values, and other notes.  This form is included in ExiFilm as a PostScript document.

I scan all of my film at a moderate resolution to JPEG files for digital light-table purposes.  It's convenient to have the notes that I took while shooting available with the files, and what better place to store them than in the files themselves.  The program ExiFilm is used to enter that information and add to the EXIF tags of the files.

I keep the original sheet film in a three ring binder, so to make the same information conveniently accessible with the film, the package includes a program that sets the metadata in the exposure record form and produces PostScript output of four exposure forms that I bind in right behind their corresponding sheet film.

From the README:

ExiFilm is a suite of programs that can be used to annotate digital images with information about the film exposure used to create them. In particular, it is designed for use with large format film cameras where the photographer may then scan the film to create a digital copy for a library or for digital processing.

By storing the exposure metadata in EXIF tags of scanned images, the photographer can have electronic access to the same information contained in the written record from the field from within an image viewer.  Further processing of the data can be done without the need to store the metadata in a separate database.


The file "lfrecord.ps" is a PostScript file that can be printed on US letter paper (or other sizes).  It is a single page of four exposure record forms design for large format photography.  The author trims the four forms and binds them together as a notepad to take into the field.  The PostScript program is hand-written and can be altered fairly easily.

The Python program "exifilm.py" provides a data entry screen similar to the form in "lfrecord.ps".  It takes an optional argument of a path to a directory with JPEG image files.  It will provide a drop-down list of JPEG files in the directory, and selecting one of the files will load the EXIF information from that file.  In this way it allows the user to quickly enter metadata for a number of scanned film images.  The metadata are saved immediately upon loading a new file or exiting the program.

The Python program "printrecord.py" loads the metadata previously entered with "exifilm.py" and produces pages similar to those in "lfrecord.ps" with the metadata typeset into the fields.  The resulting file may then be printed and bound into a photo archive with the original film.  Example usage:

  python printrecord.py /path/to/images 1 16 | lpr

Produces four pages of output including the metadata for image IDs 1 through 16.


Sweet Tea

It wasn't that long ago that "tea" meant "hot tea" everywhere except the South, where it means "sweet iced tea", or just "sweet tea".  As iced tea becomes more popular, we're now fortunate enough to have some potential for confusion when we order "tea" outside of the South.  Though I still await the day when I can order sweet tea at a California restaurant (along with all the other wonderful preparations of tea to be had).

As a transplanted southerner, I've found that I am making sweet tea in California far more often than in North Carolina.  With kitchen space at a premium, I have eschewed the single-purpose kitchen tool, the iced tea machine, and I make mine with a saucepan.  In the South, many people are accustomed to dumping most of the ice from their automatic ice maker's bin into half a gallon of tea.  I don't have an automatic ice maker, so I experimented to find the most efficient way to make iced tea.

After brewing tea bags in varying amounts of water, I observed that beyond a certain point, the amount of water and the time that the tea bags remain in the water no longer have an affect on the strength of the resulting tea.  This is in contrast to green tea which continues to get stronger the longer it steeps, and indeed, is often better in second or later brewings.

That's good news for efficient tea brewers.  That means we can use a relatively small amount of water to brew the tea, and then quench it with our single tray of ice cubes and a bunch of cold water to bring it to refrigerator temperature.

Boil 4 cups of water.  Steep 14 Lipton tea bags for 5 minutes.  Add 4/3 cups of sugar.  Maybe less.  Maybe more.  Stir until the tea is clear again.  Observe the amazing deep color of the liquid, and muse on why it's called "red tea" instead of "black tea" in China.  Drop in most of a tray of ice cubes, add water to bring it up to 1 gallon, and add the remaining ice cubes.

You're on your own if you want to use Luzianne.

Tags: food

The New Science

Fewer children are being vaccinated and community outbreaks of easily preventible but highly contagious and sometimes deadly diseases are increasing.  The change is due to many parents who are concerned that autism is linked to the administration of vaccines despite significant studies that indicate non-correlation.

But never mind the old way of doing science, this is how we do it now:

The debate over vaccination has played out in the media, with actress Jenny McCarthy saying she believes vaccines trigger autism. Her views are at odds with those of actress Amanda Peet, a spokeswoman for Every Child by Two, which promotes vaccinations.
Report: More parents choose not to vaccinate
Tags: science media

Delia Derbyshire

Delia Derbyshire was one of the pioneers of electronic sound, and is only now beginning to be recognized for her influence.

Perhaps she is most famous for her uncredited but pivotal role in the creation of the original theme music for "Doctor Who".  Her entirely electronic rendition of the piece is so powerful that the unique sounds she brought to it have persisted through its many revisions.

Most of the groundbreaking work she and her colleagues performed was done in anonymity at the BBC Radiophonic Workshop.  Ron Grainer composed the "Doctor Who" theme but it is unlikely he could have imagined the amazing new sounds she had created from scratch.  After first hearing it he asked, "Did I write that?" to which Derbyshire replied, "Most of it."

Granier requested that she share the composition credit for the piece, but the BBC declined to do so.  This decision (which apparently stands to this day as she is still absent from modern "Doctor Who" credits) certainly led in some degree to the years of obscurity she endured after leaving the BBC.

At the end of her life she saw electronic music emerge from the dark ages of the 70s and 80s and begin to realize the potential she saw in it 40 years before.  As new musicians discover the pure expressive possibilities of creating entirely new sounds, they have also discovered the amazing work of Delia Derbyshire and her contemporaries and their lasting impact on music.

Tags: music

James E. Blair

I love hacking Free Software and have been fortunate to do so professionally with some wonderful people and organizations throughout my career. This is my blog.