Oddness re Exif time

I can't figure out what's going on here?!

If I edit a Raw in DPP the saved Jpeg has a time 1 hour earlier than the original CR2 file. Even worse, when I import the Jpeg into iPhoto it becomes an hour earlier still!

I'm on a Mac [If you hadn't guessed from the iPhoto reference] and have looked through the preferences of iPhoto and DPP and see why either of them would choose to mess with the time of exposure in the Exif data.

Any ideas?

Daylight savings time? Check to make sure your computer and camera both have the same current time set.

Thanks for the input mate, but it's not really a discrepancy between camera and computer that bothers me per se. Once the file has left the camera the time in the Exif data should be set, why should an application change the Exif data? Surely it should simply read it and leave it alone?

It does look like it's something related to daylight saving time as images edited before/on 29 March have a consistent time between the CR2 and Jpeg whilst any image I've edited since then has a discrepancy - including editing pre 29 March Jpegs.

It could be a problem with the Canon compiled libraries used in DPP and how they account for change in Daylight Savings Time. Before 2007, DST in the U.S. started on the 1st Sunday of April but that was changed to the 2nd Sunday in March effective 2007. If this is similar in the U.K. its very likely that the libraries used in the SDK haven't been updated to reflect the new start of DST.

I've noticed a related problem when trying to sync my PC clock with my Canon 5D. Although it would report that the time sync was successful, my 5D clock always differed from my PC by 1 hour. I spoke with Chris Breeze who wrote the application I use to sync my cameras (Downloader Pro) and it was he who pointed out that the problem was either in the Canon compiled libraries or in the camera's firmware....he told me he had similar issues in the past because of the inconsistent way Canon handled DST in its applications and in the various camera firmware. If you check the Downloader Pro forum you'd see a few complaints about problems with time:
http://www.breezesys.c​om/forum/showthread.ph​p?t=3039
http://www.breezesys.c​om/forum/showthread.ph​p?t=3177


Make sure you have the latest camera firmware and you're using the latest version of DPP.

Thanks for that. I've got the latest 3.6.1 version of DPP, the firmware on the 450D has only just been updated in the last week, though I haven't applied it as it only pertains to an update to accommodate Canon's new flashgun.