Time fields in Lightroom metadata, where are my sub seconds?
September 8, 2010 1 Comment
I was talking with my spotter brother about the air show photos I posted on flickr and he mentioned it would be cool to include the time stamps on the multiple frame photo I posted on flickr of the USAF Thunderbirds maneuver where four F16’s fly in formation with their gear down, and a fifth F16 comes streaking in between them. The one I did quickly and posted to flickr had four frames, but this final edition has the five frames that my 7D was able to capture.
As you can see, the whole sequence took less that 2 seconds, but unfortunately, the main capture date/time field in the EXIF specification only stores the capture time at a resolution to the second. According to the EXIF specification, the format is “YYYY:MM:DD HH:MM:SS”+0x00.
Beyond that, the file format that is used to store the files on the compact flash memory card also doesn’t support a date/time stamp with a sub second resolution. Great, I have a camera capable of 8 frames per second and I can’t get the time information? Not satisfied with what I was finding, I went in search of an answer. This brought me to places in EXIF specifications I didn’t know about.Turns out, the data I was looking for is indeed there, it is just that Lightroom (running version 3.2 as of this writing) doesn’t display it. In software, and computing in general, if data is there, there should be a way to display it. I know that this data, and other proprietary EXIF fields (e.g. shutter count) aren’t guaranteed to be there, but this Sub-second data is in the EXIF 2.2 Specification under the “EXIF IFD Attribute Information” section. If Lightroom, and I also checked in Bridge CS5, finds the info, it should be able to display it. And, the more I read about EXIF, the more I can’t believe what I read about it. Adding to the issue, from Wikipedia:
Exif was created by the Japan Electronic Industries Development Association (JEIDA). Version 2.1 of the specification is dated June 12, 1998, and the latest, version 2.3 dated April 2010, was jointly formulated by JEITA and CIPA. Though the specification is not currently maintained by any industry or standards organization, its use by camera manufacturers is nearly universal.
Wonderful, a standard that isn’t! So not only do you have to contend with multiple RAW formats (at least there might be some hope with DNG), you have possibly inconsistent metadata in the form of proprietary EXIF fields.
The Solution
One of the way to get at this data is to put the file through EXIFTool, a great little utility by Phil Harvey. Using this command line/terminal application, I was able to extract the “SubSecTime” field from the EXIF data and include it in the final image. So, instead of saying the whole sequence took less that 2 seconds, I can tell you that it took 1.34 seconds. I think this gives you even more appreciation for just how precise those USAF Thunderbird pilots are:
Is there is a way to get Lightroom to display this? Do other mainstream photography applications like Aperture have the ability to display this information? Please let me know, and, in case you are looking for what other information is lurking in all the EXIF info that a Canon 7D spits out, you can have a look at the full EXIF data, as extracted by EXIFTool for the first frame, from the DNG file.