My take is simple. In the old days of film I would spend time writing the data down in little books for reference later. A friend of mine went further than that and can tell you when he took a certain slide or negative, the year, day, date, and hour. He can also look up the film stock used, lens, aperture, shutter speed and weather conditions that prevailed at the time. Some of his work goes back to the late 1960's, but everything is logged and numbered meticulously for future research. Now we have all the info we need for our own use within the image file and for me that's a godsend, as I don't have to carry those daft little pocket books around anymore.
