Set camera clock to GMT for better geotagging?
Tell me what to do here, folks.
I encountered a rat's nest of problems with geotagging recently because I'd left my camera clock to local time on a vacation eight time zones away. Some have suggested to me that I change my camera clock to Greenwich Mean Time (GMT), the closest thing the planet has to an absolute time zone reference point, as an easier way to embed location information in my digital photos.
I've been reluctant to make the GMT switch because I didn't want a photo I took at, say, 8 p.m. California time to be indexed on my computer as 4 a.m. the next day. Maybe I'm too parochial, but I sometimes want to know the real time I took my shot, not some relative time where I have to subtract seven or eight hours. And of course the issue extends to photo-sharing sites: might a friend be unable to find a wedding photo I uploaded, because he's searching by date and doesn't know to look one day in the future?
But on the flip side, I plan to geotag my photos routinely now, and I don't want to repeat my earlier problems.
So tell me, geotaggers, should I tell my camera clock it's nearer to Big Ben than the San Francisco Ferry Building? What are the downsides, and are there any other upsides?
Feel free to e-mail advice to me directly at stephen.shankland@cnet.com or post below in the Talkback section so others can benefit.
Also, for finer time adjustments, here's a good tip I heard from Jeffrey Early, author of the GPSPhotoLinker geotagging software (who was one of the folks who suggested I move to GMT). Geotagging software often lets you precisely synchronize your camera and GPS times, but what's the best way to see if your camera clock has drifted away from your GPS. Take a photo of the GPS clock and compare the subject of the photo with its timestamp.
Stephen Shankland covers Google, Yahoo, search, online advertising, portals, digital photography, and related subjects. He joined CNET News in 1998 and since then also has covered servers, supercomputing, open-source software, and science. E-mail Stephen.
When/if public posting of my photos becomes my biggest priority, I'd definitely make the switch, but not before.
If the site DOES have that function, "universalizing" the camera's clock becomes moot.
however, suggest that you also posting your question on DP
Review's "Open Talk" Forum at:
http://forums.dpreview.com/forums/forum.asp?forum=1018
Good shooting!
What?s more important to you? Having a definite time for your geotagging, or a convenient time that matches expectations? If it is important that your most sensitive photos have the correct absolute time then I?d go with using GMT, also the same if I was frequently travelling around the world.
What is local time anyway but a fudge of the real time so that everyone wakes up at 7am no matter what where in the world they are. Right now, somewhere it?s 5pm and someone is leaving the office. Local time is made even more perplexing by it then being adjusted by summertime which is too arbitrary. (?Hey guys, we won?t tell you to wake up an hour early, instead we will change our clocks.?)
It?s too bad that in these days of worldwide communications that we have to deal with over 25 different times zones and an international dateline to calculate local time. Why not just switch to UTC for most communications? I?ve personally experienced issues dealing with time zones (EST -5 , CST -6 , PST -8, GMT & India +5.5) and Summertime (July & Brazil = EST + 3 / December & Brazil = EST + 1).
What would it hurt to say that in Boston, the work day starts at 14:00 and ends at 22:00 and in the summer starts an hour earlier? It?s not that radical, Arthur C. Clarke mentioned a single world time zone in a book of his many years ago.
The additional problem I have is that I merge data between a NMEA file and an image using Downloader Pro after the fact so it will require some synchronization to make sure everything ties together properly.
But for now, my pictures are showing up where I expected them to be and I'm pretty happy with the results.
http://flickr.com/photos/jauderho/sets/72157602229609984/