Time Travel With Adobe Lightroom
As traveling photographers, we often change time zones while jetting across the U.S. or the world. And if we want to keep the metadata on our images – specifically, the metadata that tells us the exact time an image was captured – we face a minor dilemma. Do we adjust the clock on our camera to the new time zone or do we do it later in software? Or do we skip it altogether?
I have tried all three approaches and, as I revisit some of my older images, I’ve found that “skip it altogether” is a little too popular with me.
And, when I’ve remembered to adjust the clock on my camera, I’ve usually forgotten to change it back once I’ve returned home. I end up with weeks worth of photos marked with the old time zone before I realize my mistake.
So for me, it’s a lot easier to leave the camera’s clock alone and, instead, change the capture time after the fact in software. My image management software of choice is Adobe Lightroom. And Lightroom makes it pretty easy.
What Time Was It Then?
First you need to know what the correct local time when the images were created. This is not so difficult if you make the corrections soon after returning home.
But what about those old images of mine that still have the incorrect time? Time zones stay the same, but how do I account for Daylight Savings Time? There is a website called The World Clock that makes it pretty easy to figure the time difference between cities in the USA or worldwide.
Enter your home city – or one nearby – and the visited city. Then, change the date and time fields to the capture time shown in the EXIF metadata from one of your old images – or as close as you can get to it; the “minutes” menu only has settings in 5-minute intervals. You can choose a year as far back as 1970.
Now, click on the Convert button. You’ll be taken to the results page which has more information than you need. Check the two times listed under the Location column. My results show that when it was 5:55 a.m. in San Diego (the time zone my camera was using), it was actually 8:55 a.m. in Vermont on the day I specified. So, now I know that I need to add three hours to the capture time for all of my Vermont photos from that trip.
To make it simpler to determine the local time – with no website required – it would be a good idea to photograph a clock on location and compare the time the clock shows to the capture time of the image. Maybe I can remember to start doing that.
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Spring Forward or Fall Back
Now that we know the time difference, we can change the capture time. Start by opening Lightroom and selecting all of the images from the location in question.
Once they are all highlighted, go to Lightroom’s Metadata menu and choose Edit Capture Time. The Edit Capture Time window pops up.
From the dropdown menu to the right – which is set to zero by default – choose the appropriate amount of time correction. In my case, I’ll choose +3. Now the Corrected Time field has changed to show the new capture time. Double check this to make sure it is correct. Then click the Change All button. The capture time will now be changed for all of the selected images. (Note: If you’ve only selected one image, the button text will say Change instead of Change All.)
If you make a mistake, you can change the time back to the original by selecting the same images again and choosing Revert Capture Time to Original from the Metadata menu.
Lightroom records date and time in several different fields. The capture time of the image is recorded in the field called Date Time Digitized. This is the field that will change when you edit the capture time. The fields called Date Time Original and Date Time will also change. Apparently, there are some cameras where these three fields may hold different data, but for most – my Nikons included – all three of these will contain the exact same data.
A fourth field called Metadata Date does not contain the capture time. It records the time the file was last modified. So, this will change when you update the capture time, but it will change to the current time; the time you made the change. It will not match the other three time/date fields.
By default, the time changes you make will be written into Lightroom’s sidecar XMP file, but the actual raw file’s time will not change. This is fine if you use only Lightroom or some other program that is smart enough to recognize the XMP files. But, if you regularly use other image management or editing software, such as ACDSee Pro, it will not read the XMP file. So, the capture time that it reports will not reflect any changes you’ve made by using the Edit Capture Time command in Lightroom.
If you want all of your image processing programs to recognize the correct time, you’ll need to change the catalog settings in Lightroom. Go to the Edit menu and choose Catalog Settings. Or, if you’re already in the Preferences window, you can click on the Go to Catalog Settings button. In the Metadata tab of Catalog Settings, add a checkmark in the box next to “Write date or time changes into proprietary raw files.” Now, any program that can read the EXIF data in a raw file will see the correct capture time.
Time To Go
How important is it all this time stuff? Here’s an example. Sometimes I use more than one camera and I later find that one is set to the wrong time zone. Using Lightroom, I can correct this error so that I can view images from both cameras in the correct chronological sequence.
Capture time is one piece of your images’ metadata. Since Adobe Lightroom makes it easy, it may as well be correct.