Captured Time


This bit from the film Spectre of Hope has been on my mind recently:

This notion of capturing the world in what is cumulatively a very small amount of time is interesting to me, and I realized that, given that all of my digital photos record the exposure for each frame, I could calculate exactly how much actual time I have recorded. I wrote a script (details on that after the jump) to do just this for all the photos I've taken since I got my first camera in 2002, and the total exposure time for 27611 images is 2360.473 seconds, or a bit under 40 minutes. That I take the occasional long exposures inflates this figure to a certain extent, but even with that it's a small amount of time for something that feels a lot longer.

By the way - Spectre of Hope is currently available in its entirety on YouTube in 5 parts: part 1, part 2, part 3, part 4, part 5.

Script Details

I used Ruby for this. For jpg images, it's easy using the exifr library:

Dir.glob(photo_dir + "/**/*.jpg") do |img|
    exposure =;
    puts "Problem reading exif from file " + img
  if (exposure)
    total_exposure += exposure

However, once I started using RAW for all my pictures, it became more complicated, as the exifr library supports jpeg and tiff files only. I ended up parsing the Lightroom metadata files instead:

Dir.glob(photo_dir + "/**/*.xmp") do |img|
  doc = XML::Document.file(img);
  exposure = doc.find("//exif:ExposureTime", 'exif:').first.content
  exp = exposure.split('/')
  num = Rational(Integer(exp[0]), Integer(exp[1]))
  total_exposure += num

This took me a while to develop, as the XMP format is RDF, and I could not make REXML play nicely with it. LibXML did the job with no problems.


Bill, that clip has some tremendous photography in it. Wow! Thank you for sharing it :)

As a Oral Storyteller I was interested in the aspect of time in getting the listeners mind to where the story is to be but I never looked at time frames of a picture like that and am interested in seeing if I can relate the ssame idea into a story.

Thank for the imput.

About this Entry

This page contains a single entry by was published on March 29, 2009 2:16 PM.

Things To Read and A Thing To Possibly Use was the previous entry in this blog.

Weschler on Trevor and Ryan Oakes is the next entry in this blog.

This is, a weblog by Bill Stilwell. I take the occasional photo.


Powered by Movable Type 4.24-en