Re: Time synchronization [was: GPS geotagging: first steps to implementation]

[Jan Girlich <vollkorn cryptobitch de>]

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Am 18.09.2010 03:44, schrieb Michael Lissner:
> I guess something I didn't understand about this was that the photos from the
> camera remain in UTC at the end of this process.

True. I think this is the best option for storing pictures anyway
because then you don't have problems like picture A being taken before
picture B, but displayed the other way around because they were taken
while crossing timezones and adjusting camera time and thus A having a
later local timestamp than B.

> That seems strange to me
> because while that's an accurate representation of the time, it's not a time
> that's useful for people -- it gives the picture very little context. This might
> be good for photographers, but as a normal camera user, I'd be annoyed if my
> picture of the sunset had a timestamp of 6am (or similar), even if I knew there
> was a good reason for it.

I strongly advocate for internally storing and handling times in UTC
plus positions or timezones and displaying times in the userinterface in
either a user selected time zone or the local time derived from UTC +
position/timezone. Also I would tell the used timezone with the
displayed time. Just three letters to add.

> I also didn't realize that the barcode pictures could be taken at any time
> before or after a series of pictures was taken. That's interesting, and makes me
> think that there may be no need to take the barcode picture except for once per
> camera, right? Then, F-Spot could identify the camera each time there was an
> import, and forevermore make the needed correction? That would work so long as
> the time on the camera didn't change along the way, which is most-likely
> wouldn't, right?

You got it! That's the optimum case, but unfortunately some cameras
loose their time settings when off battery for too long or have a strong
drift. So maybe once every couple of weeks or so.

Cheers
Jan
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