EXIF Time Confusion

February 22, 2010 8:17 PM

Do you update your camera clock when you travel across timezones? Does this happen automatically with some cameras?

Since EXIF does not store timezone, I'm confused about how people tend to deal with this issue. Do you care about the date your photo was taken? Do you leave them in your "home timezone" or do you update it when you get to your travel destination?

Also, do some cameras that are timezone aware, like the iPhone, automatically update? That is, if I traveled to Japan and took a photo with my iPhone, would the EXIF timestamp say the local time in Japan? Does this depend on a setting and if so, which setting is default?

Thanks. Any help is appreciated.

posted by whiskeyspider to Technology (12 answers total)

I always update if I remember, because I hate having pictures of sunrises that report being taken at 3AM and night shots that claim to be mid-afternoon. Some cameras (e.g. all recent Canon Powershots) support setting a home time zone and a traveling (I think it's called "world") time zone, then you can just switch between them without having to change the time itself forward and back.

I'm not aware of which (if any) cameras update automatically, but I do know that if you forget to reset it, there are tools which can do bulk operations on a folder full of files, so you can, for example, add six hours to every image. Here's one (found on a quick google, but it looks like it'd do the job).
posted by Partial Law at 8:26 PM on February 22, 2010

Small data point: every cameraphone I've ever owned updated itself automatically across US timezones.
posted by box at 8:31 PM on February 22, 2010

box: Those are just how cellphones work by design -- not specific to the camera itself.
posted by special-k at 8:36 PM on February 22, 2010

I just manually set it every time I travel.
If I forget, I just offset the exif info for batches of images grouped by location.
posted by special-k at 8:37 PM on February 22, 2010

What you could also do is set your camera time to be GMT (Greenwich mean time). Then you will just have to calculate the offset for where you were at the time of the photo. Still involves converting the time using some software offset calculator though. (I guess as long as you know what timezone your camera is set to, and what timezone you were in, you can use software to change the 'taken on' time)
posted by defcom1 at 8:58 PM on February 22, 2010

I almost always "forget" to reset my camera clock when I travel (it's more like intentionally forgetting at this point) and just update the EXIF data when I import the photos. I use Aperture for my photo management, which has a handy time zone converter right in the import panel, so it's pretty painless.

Also, while EXIF doesn't store timezone in the date field, some cameras (I know my D90 will) will keep track of the time zone and store it in the metadata another way. For example, the TimeZoneOffset field. Cameras could also stick the UTC time in the GPSTimeStamp field (even if they don't have GPS) and software can compare the two time fields to find the offset. There's a flickr forum thread that goes into a bit of detail on this. In any case, the end result is that my computer always "knows" that the camera clock was set to PST when I go to import photos.
posted by zachlipton at 9:23 PM on February 22, 2010

I try to remember although if I forget then it hasn't been a complete disaster as Picasa only really starts mucking up the ordering if I have the year wrong.

If you are running Windows then this application will correct the EXIF datestamp on your pictures.
posted by mr_silver at 12:24 AM on February 23, 2010

I don't update the camera time, instead I update my watch and take a photo of that.
When I get home I use exiftool to fix the times.
posted by devnull at 2:41 AM on February 23, 2010

If you're planning to geotag your photos, updating your camera time can cause trouble for the later sync of photos to your gps track. (Although if you're mostly staying in one time zone when you're away, it's not so bad). If you do update it, make sure to correct the timezone in whatever software you're using to geotag.
posted by dttocs at 6:06 AM on February 23, 2010

I keep the camera set to UTC.
posted by massysett at 6:51 AM on February 23, 2010

The Panasonic Lumix GF1 has a great vacation mode - you tell it where you're going and on what days, then when you're on vacation and turn it on, it says "DAY 1 - SAN FRANCISCO" or something like that.
posted by Gortuk at 6:44 AM on February 28, 2010

Sorry, I don't use exiftool. I use jhead. It's great.
posted by devnull at 4:38 AM on March 4, 2010