A S C R A P B O O K O F S O L U T I O N S F O R T H E P H O T O G R A P H E R
Reviews of photography products that enhance the enjoyment of taking pictures. Published frequently but irregularly.
11 March 2013
When we reminded you Saturday about the time change, we promised a solution today for anybody who forgot to change the clock on their camera and took a few shots on Sunday.
We could punt and point you to one image editing application or another (like Lightroom) that can adjust the Capture Time for you. Even on a set of images.
But we prefer to turn everything into an entertaining lesson.
And today's lesson is how to use Phil Harvey's free ExifTool to change the three tags (yep, there's more than one) in your Exif header that record the capture time.
So what are these three tags camera manufacturers use to record the capture time in the Exif header of their image files? DateTimeOriginal, CreateDate and ModifyDate tags all record it, so you have to reset all three when you change the time on an image.
ExifTool can conveniently do that with just one simple command. The direct way is to use the utility from the command line (Terminal on the Mac).
But we've also put together Photo Time Machine, an AppleScript front end to make this even easier for Mac users. With ExifTool installed, just drag a bunch of image files to the droplet and click on either the Fall Back or Spring Forward button to make the change.
Your original files will be overwritten, so you might want to experiment with copies of them at first.
To do the same thing as our Photo Time Machine in ExifTool, navigate to your directory of incorrectly time-stamped images (it's optional but helpful). Then just tell ExifTool to spring forward an hour on all the images:
exiftool -AllDates+=1 *
The program is invoked with the -AllDates switch set to add one hour. The asterisk simply means in this directory.
To fall back, it's just as simple:
exiftool -AllDates-=1 *
And it works for JPEGs and Raw files, too.