If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#11
|
|||
|
|||
EXIF time stamps
Terry Pinnell wrote:
VanguardLH wrote: Terry Pinnell wrote: VanguardLH wrote: Terry Pinnell wrote: I'm struggling to determine the times at which my holiday photos in Italy were taken with my iPhone. This illustration of IrfanView windows hopefully states my questions clearly: https://www.dropbox.com/s/hcrzd9nxf9...ps-01.jpg?dl=0 Looks like an hour difference between meta-data datestamp and file datestamp. Is one device set to use DST and the other not? Meta-data is static. The device writes the meta-data at the time the photo is taken and the meta-data stays that way no matter how time thereafter changes on your phone. Copying a file would change its timestamp in the file system but not alter any meta-data which is contained within the file. Since the timestamps in the meta-data and Irfanview are the same to the second, I'm guessing you removed a memory card and slid it into a reader on your computer and that is where you are using Irfanview to look at the file. That way you would not have copied the file to change the timestamp. Could be your phone and computer are set to use different DST offsets. The phone likely locks in the current time regardless of where it is: Italy, home, wherever. That won't change the meta-data in the file recorded at the time of taking the photo. Don't know how your computer is setup for DST or if it is even configured for the correct timezone. Thanks both. Time is set automatically on iPhone/iPad/Win 10 PC. (Settings General Date and Time Set Automatically.) The iOS devices were set correctly during my holiday in Italy as time zone is automatically changed. A photo take with the iPhone just now here in UK shows all four of those dates are identical in a similar IrfanView screenshot. Note that it automatically gets named 2017-06-09 10.03.38.jpg. I rename that (with a macro, or in volume with Bulk Rename Utility) to the form yyyymmdd-hhmmss. In this case 20170609-100338.jpg. I'm still hazy as to why all my iPhone photos taken in Italy have that IrfanView Properties date showing UK BST, while the EXIF window correctly shows CEST. More coffee and I might get it... Terry, East Grinstead, UK But you are NOT running Irfanview on your phone. You are running it on your computer. How did you get the photos from your phone to your computer? Uploaded to my PC via Dropbox. Since the timestamp of the file is identical to the timestamps in the meta-data but different by 1 hour, I suspect your computer is looking at the timestamp on the file and biasing its presentation in your file system per your regional time settings in your computer. Certainly sounds like you may be onto something, although I won't claim to have got my head around it yet. And I'd have expected to see this potential cause of confusion being discussed more widely, given the number of iPhone/iPad users. What's your view about the relevance of the article referenced by Shadow? When you were in Italy taking photos on your phone, did your phone adjust for DST? Now that you're back home, is your phone showing the correct local time or is it off by an hour? Is your home locale using DST or not? What was the timezone for your phone at that you were in Italy? What is the timezone for your home computer? As I said in my previous post: "Time is set automatically on iPhone/iPad/Win 10 PC," and "The iOS devices were set correctly during my holiday in Italy as time zone is automatically changed." So: - Yes, it showed CEST (Central European Summer Time, GMT/UTC+0200) - Yes, it shows correct time - Yes, 'correct' obviously means BST - (Again) CEST - BST Don't know how you are getting the photo from your phone to your computer. If you copied the file, it would get a new timestamp since it is a new file. Did you move a memory card from phone to computer? If so, if you put the card back in your phone, what does it show for the file's timestamp? I answered that above. Do you have a smartphone? It sounds not. Upload of photos from smartphones (iOS, android, Windows) is a rather commonplace operation these days. It's almost entirely done online, via wifi or 3G/4G. Terry, East Grinstead, UK In case it offers further clues, for the photo example in my earlier illustration, here is all the data on Date/Time reported by Win 10. Even more elements than I thought, although most are empty. https://www.dropbox.com/s/1nr6sfeu0q...ments.jpg?dl=0 BTW, with apologies for digressing, I just viewed it in IrfanView and closed it again, and was surprised that did not change 'Date accessed'. So then (without editing) I resaved it - but no change in 'Date last saved'. Then I edited it and resaved, but STILL no change to 'Date last saved'! FWIW, this was working on a backup copy on a 2 TB USB HD, although I don't see how that's a factor? Terry, East Grinstead, UK |
#12
|
|||
|
|||
EXIF time stamps
Shadow wrote:
On Fri, 09 Jun 2017 13:41:53 +0100, Terry Pinnell wrote: Shadow wrote: On Fri, 9 Jun 2017 04:46:07 -0500, VanguardLH wrote: But you are NOT running Irfanview on your phone. You are running it on your computer. How did you get the photos from your phone to your computer? Since the timestamp of the file is identical to the timestamps in the meta-data but different by 1 hour, I suspect your computer is looking at the timestamp on the file and biasing its presentation in your file system per your regional time settings in your computer. NTFS buggers my timestamps by one hour when I'm in the daylight saving period. I found a link he https://support.microsoft.com/en-us/...ylight-savings But can't read it, because of my hosts file. It probably explains it. []'s Thanks, interesting page, and a quirk I hadn't heard about. However, at first sight I read it as arising only at clocks forward/backward times? But then I've never properly grasped the technical details behind the various date/time fields in Windows: Modified, Accessed, Created, Taken - and in Win 10 an apparently new (redundant?) one called 'Date'. Unless perhaps the part about "... viewing another machine remotely across one or more time zones through Event Viewer" also applies to uploading files via Dropbox? Like I said, I can't read the page. I don't keep any files "on the web", and I don't use Win 10 This might help: https://en.wikipedia.org/wiki/NTFS#Time Unfortunately the reference https://en.wikipedia.org/wiki/NTFS#cite_note-57 "Beating the Daylight Saving Time bug and getting correct file modification times - The Code Project" is dead []'s I found the article of that name here https://www.codeproject.com/Articles...ug-and-getting but haven't yet studied it. Looks a bit daunting and not sure it's worth the effort. Terry, East Grinstead, UK |
#13
|
|||
|
|||
EXIF time stamps
Terry Pinnell wrote:
Do you have a smartphone? It sounds not. Upload of photos from smartphones (iOS, android, Windows) is a rather commonplace operation these days. It's almost entirely done online, via wifi or 3G/4G. Yep, have a smartphone (Samsung Galaxy Core Prime aka G360). Never uploaded photos to it, only downloaded from phone to PC. I could use Bluetooth, wifi, or USB. To charge it when not in use, I have a USB stand. I just use the AutoPlay popup in Windows when I connect the phone to the USB stand to transfer photos from phone to PC. I'm not a photo junky even when I do travel. They'd really be to give to others but then I'm not into doing travelogues with others. Mostly I take pics of stuff that I am selling, a car accident, or some occasional use. After taking a couple pics with the phone and waiting 5 minutes leaving the phone disconnected from the USB stand, I plugged the phone into the stand. The 5 minutes was to ensure some time elapsed from when the pics were taken. The AutoPlay popup appeared and I had it transfer the pics from phone to PC. I wanted to see if the file transfer would retain the original timestamp of the file as it would be on the phone. That is, I wanted to test if the file transfer did a copy operation but used the original timestamp from the file on the phone for the timestamp of the new file created on the PC. I figured 5 minutes would be enough to see a difference in timestamps. After importing the pics to my PC, the timestamp on them said they were taken 9 minutes ago. So the file transfer retained the original timestamp for the file on the phone (instead of using a new timestamp for the new files created on the PC). Maybe using a different copy operation would've set a new[er] timestamp on the files that got created on the PC than the timestamp for the files on the phone. The transfer kept the original timestamp. Still don't know how you transfer your photos from phone to PC but maybe that method also retains the original timestamps. It appears then there is a difference in regional settings on your phone versus your PC, like DST enabled on one and not the other or a difference in timezones. Having the phone or PC automatically sync its OS time (using the cellular carrier for the phone or to some NTP server for the PC) does not mean they are configured for DST changes or the same timezone. Since this was a trip to Italy, presumably that is not your home region. Where is home and your PC, is it an hour difference in timezone from Italy? From what I recall of Irfanview (haven't used it for a while), it is a Windows-only program (no *NIX variant), so the one-hour off on timestamp is an issue for the photo transfered to a Windows host. To look at your regional settings in Windows 7 (don't know what you have): - Go to Control Panel - Region and Language. Under the Location tab, is it the same as the current physical region for your PC? Not sure how this will affect timestamps but it is a regional setting. - Go to Control Panel - Date and Time: o Under the Date and Time tab, is the timezone set for the current locale of your PC? o Click on the "Change time zone" button. Is the option "Automatically adjust clock for Daylight Saving Time" enabled? o With the DST option enabled, go back to the main screen of this dialog and pick the Internet Time tab. * The "Synchronize" option should already be enabled. * I use the time.nist.gov NTP server but you might pick something else. Microsoft's can be overly busy with all the Windows hosts defaulting to point there. * Click "Change settings" button and then click "Update now". Did your OS clock change by an hour? I believe Italy honors DST. Does your locale honor DST? Some places don't in which case DST should probably be disabled in the time settings. |
#14
|
|||
|
|||
EXIF time stamps
Terry Pinnell wrote:
What's your view about the relevance of the article referenced by Shadow? His posts are hidden (flagged as ignored) in my "Hide Ignored Message" default view. I'm not wasting time here on why I filter out his posts. I don't delete undesirable posts. Instead I flag their posts as ignored and use a default view that hides ignore-flagged posts. The entire subthread gets ignored, too, since I'm not interested in reading replies to posts that I've decided to ignore, so I also did not see your reply to Shadow. I can change my view to "All Messages" to see the ignore-flagged messages so I could then see to what he linked (that he cannot read due to his blocking so I have to wonder how he knows that it is apropo to your situation). I mentioned checking the DST option in your PC and asked if your PC's locale honors DST (not all do). Also mentioned checking your PC's timezone is correct to its locale. For example, maybe you moved to a timezone 1 hour different than where you were before but did not change the timezone in Windows. You might change the time to match the local time but timestamps would still be off an hour because your timezone is incorrect. |
#15
|
|||
|
|||
EXIF time stamps
Terry Pinnell wrote:
BTW, with apologies for digressing, I just viewed it in IrfanView and closed it again, and was surprised that did not change 'Date accessed'. So then (without editing) I resaved it - but no change in 'Date last saved'. Then I edited it and resaved, but STILL no change to 'Date last saved'! FWIW, this was working on a backup copy on a 2 TB USB HD, although I don't see how that's a factor? If you talking about the meta-data in the image file, that won't change unless the editor regenerates it. Many users have complained about editing a photo in Irfanview, saving the changes, but the meta-data still shows the same old information. In fact, part of the meta-data is a thumbnail and users were frustrated that the edited photo did not show an updated thumbnail in File/Windows Explorer. That's because those show the meta-data's thumbnail instead of building their own. I'd have to go research again but remember that users found an option in Irfanview of whether or not to regenerate the meta-data when the image file got edited. In fact, you and I had this discussion before (titled "Thumbnail inconsistency") in the Windows 10 newsgroup about thumbnails stored in the meta-data of an image file where I mentioned 'do NOT enable "Keep original EXIF data" option' in Irfanview. If you want a changed photo file to reflect the changes in its meta-data, you have to tell Irfanview to generate new meta-data on the changed file that you save; else, Irfanview propagates the old EXIF data in the changed file. |
#16
|
|||
|
|||
EXIF time stamps
VanguardLH wrote:
Terry Pinnell wrote: BTW, with apologies for digressing, I just viewed it in IrfanView and closed it again, and was surprised that did not change 'Date accessed'. So then (without editing) I resaved it - but no change in 'Date last saved'. Then I edited it and resaved, but STILL no change to 'Date last saved'! FWIW, this was working on a backup copy on a 2 TB USB HD, although I don't see how that's a factor? If you talking about the meta-data in the image file, that won't change unless the editor regenerates it. Not sure I follow you. As I admitted, it was a digression, but I thought I showed exactly what I was 'talking about' in my screenshot. Here it is again: https://www.dropbox.com/s/1nr6sfeu0q...ments.jpg?dl=0 Many users have complained about editing a photo in Irfanview, saving the changes, but the meta-data still shows the same old information. In fact, part of the meta-data is a thumbnail and users were frustrated that the edited photo did not show an updated thumbnail in File/Windows Explorer. That's because those show the meta-data's thumbnail instead of building their own. I'd have to go research again but remember that users found an option in Irfanview of whether or not to regenerate the meta-data when the image file got edited. In fact, you and I had this discussion before (titled "Thumbnail inconsistency") in the Windows 10 newsgroup about thumbnails stored in the meta-data of an image file where I mentioned 'do NOT enable "Keep original EXIF data" option' in Irfanview. If you want a changed photo file to reflect the changes in its meta-data, you have to tell Irfanview to generate new meta-data on the changed file that you save; else, Irfanview propagates the old EXIF data in the changed file. Yes, I think at that time I possibly followed suit and unchecked "Keep original EXIF data". Looking just now, this was the state of my settings for that and another clearly significant option, "Save with original date/time": https://www.dropbox.com/s/iwy6k7lihd...ngs-1.jpg?dl=0 Terry, East Grinstead, UK |
#17
|
|||
|
|||
EXIF time stamps
VanguardLH wrote:
Terry Pinnell wrote: Do you have a smartphone? It sounds not. Upload of photos from smartphones (iOS, android, Windows) is a rather commonplace operation these days. It's almost entirely done online, via wifi or 3G/4G. Yep, have a smartphone (Samsung Galaxy Core Prime aka G360). Never uploaded photos to it, only downloaded from phone to PC. I could use Bluetooth, wifi, or USB. To charge it when not in use, I have a USB stand. I just use the AutoPlay popup in Windows when I connect the phone to the USB stand to transfer photos from phone to PC. I'm not a photo junky even when I do travel. They'd really be to give to others but then I'm not into doing travelogues with others. Mostly I take pics of stuff that I am selling, a car accident, or some occasional use. After taking a couple pics with the phone and waiting 5 minutes leaving the phone disconnected from the USB stand, I plugged the phone into the stand. The 5 minutes was to ensure some time elapsed from when the pics were taken. The AutoPlay popup appeared and I had it transfer the pics from phone to PC. I wanted to see if the file transfer would retain the original timestamp of the file as it would be on the phone. That is, I wanted to test if the file transfer did a copy operation but used the original timestamp from the file on the phone for the timestamp of the new file created on the PC. I figured 5 minutes would be enough to see a difference in timestamps. After importing the pics to my PC, the timestamp on them said they were taken 9 minutes ago. So the file transfer retained the original timestamp for the file on the phone (instead of using a new timestamp for the new files created on the PC). Maybe using a different copy operation would've set a new[er] timestamp on the files that got created on the PC than the timestamp for the files on the phone. The transfer kept the original timestamp. Still don't know how you transfer your photos from phone to PC but maybe that method also retains the original timestamps. You asked me that twice before! "Uploaded to my PC via Dropbox." My iPhone automatically uploads photos from my camera roll to C:\Users\terry\Dropbox\Camera Uploads\ whenever I have wifi and the Dropbox app is running on the iPhone. It appears then there is a difference in regional settings on your phone versus your PC, like DST enabled on one and not the other or a difference in timezones. Having the phone or PC automatically sync its OS time (using the cellular carrier for the phone or to some NTP server for the PC) does not mean they are configured for DST changes or the same timezone. Since this was a trip to Italy, presumably that is not your home region. Where is home and your PC, is it an hour difference in timezone from Italy? UK - as in my sig! From what I recall of Irfanview (haven't used it for a while), it is a Windows-only program (no *NIX variant), so the one-hour off on timestamp is an issue for the photo transfered to a Windows host. To look at your regional settings in Windows 7 (don't know what you have): - Go to Control Panel - Region and Language. Under the Location tab, is it the same as the current physical region for your PC? Yes Not sure how this will affect timestamps but it is a regional setting. - Go to Control Panel - Date and Time: o Under the Date and Time tab, is the timezone set for the current locale of your PC? Yes o Click on the "Change time zone" button. Is the option "Automatically adjust clock for Daylight Saving Time" enabled? Yes o With the DST option enabled, go back to the main screen of this dialog and pick the Internet Time tab. * The "Synchronize" option should already be enabled. * I use the time.nist.gov NTP server but you might pick something else. Microsoft's can be overly busy with all the Windows hosts defaulting to point there. Mine is using 'time.windows.com'. * Click "Change settings" button and then click "Update now". Did your OS clock change by an hour? Naturally, no, why would it, given that it's already accurately set? I believe Italy honors DST. Does your locale honor DST? Some places don't in which case DST should probably be disabled in the time settings. I think we invented DST! Terry, East Grinstead, UK |
#18
|
|||
|
|||
EXIF time stamps
VanguardLH wrote:
Terry Pinnell wrote: What's your view about the relevance of the article referenced by Shadow? His posts are hidden (flagged as ignored) in my "Hide Ignored Message" default view. I'm not wasting time here on why I filter out his posts. I don't delete undesirable posts. Instead I flag their posts as ignored and use a default view that hides ignore-flagged posts. The entire subthread gets ignored, too, since I'm not interested in reading replies to posts that I've decided to ignore, so I also did not see your reply to Shadow. I can change my view to "All Messages" to see the ignore-flagged messages so I could then see to what he linked (that he cannot read due to his blocking so I have to wonder how he knows that it is apropo to your situation). My reply to Shadow was: "Thanks, interesting page, and a quirk I hadn't heard about. However, at first sight I read it as arising only at clocks forward/backward times? But then I've never properly grasped the technical details behind the various date/time fields in Windows: Modified, Accessed, Created, Taken - and in Win 10 an apparently new (redundant?) one called 'Date'. Unless perhaps the part about "... viewing another machine remotely across one or more time zones through Event Viewer" also applies to uploading files via Dropbox?" And subsequently: "I found the article of that name here https://www.codeproject.com/Articles...ug-and-getting but haven't yet studied it. Looks a bit daunting and not sure it's worth the effort." I mentioned checking the DST option in your PC and asked if your PC's locale honors DST (not all do). Also mentioned checking your PC's timezone is correct to its locale. For example, maybe you moved to a timezone 1 hour different than where you were before but did not change the timezone in Windows. You might change the time to match the local time but timestamps would still be off an hour because your timezone is incorrect. As indicated earlier, all that basic stuff seems OK. See my replies a few minutes ago. Terry, East Grinstead, UK |
#19
|
|||
|
|||
EXIF time stamps
Terry Pinnell wrote:
VanguardLH wrote: Terry Pinnell wrote: BTW, with apologies for digressing, I just viewed it in IrfanView and closed it again, and was surprised that did not change 'Date accessed'. So then (without editing) I resaved it - but no change in 'Date last saved'. Then I edited it and resaved, but STILL no change to 'Date last saved'! FWIW, this was working on a backup copy on a 2 TB USB HD, although I don't see how that's a factor? If you talking about the meta-data in the image file, that won't change unless the editor regenerates it. Not sure I follow you. As I admitted, it was a digression, but I thought I showed exactly what I was 'talking about' in my screenshot. Here it is again: https://www.dropbox.com/s/1nr6sfeu0q...ments.jpg?dl=0 I thought the "digressing" paragraph was where you digressed so I focused on that content thereafter. Since there was no change, I thought you were talking about the file's meta-data. Sorry. As a test (in Windows 7), I created a .txt file and opened it in Notepad, added some content, and exited Notepad while saving the file. I waited 6 minutes before reopening that .txt file in Notepad, made no changes but used File - Save and exited Notepad. The last access timestamp did not change. I opened the file in Notepad, made some changes, exited Notepad while saving the changed file. The modified timestamp changed but the access time did not. https://msdn.microsoft.com/en-us/lib...(v=vs.85).aspx In FAT, access time has a resolution of 1 day. NTFS delays updates to the last access time for a file by up to 1 hour after the last access. The granularity is not what you expected. Some files can remain constantly open, like a database or cache, and get repeatedly accessed thousands of times per minute. Having to update the file attributes for the record in the file table that often would add so much overhead that file I/O would crawl. |
#20
|
|||
|
|||
EXIF time stamps
Terry Pinnell wrote:
You asked me that twice before! "Uploaded to my PC via Dropbox." My iPhone automatically uploads photos from my camera roll to C:\Users\terry\Dropbox\Camera Uploads\ whenever I have wifi and the Dropbox app is running on the iPhone. And you could've copied the file from your phone to your PC where there is a folder that Dropbox keeps in sync with your account. So you're using an app on your phone to go from it to your Dropbox account. Your PC is not involved except to download the file from your online account to your PC. UK - as in my sig! I tend to ignore signatures, even those not in a sig block. I probably saw "Terry blah blah blah" but already knew you were Terry from the From header in your posts that shows up in the headers pane of my NNTP client showing who posted what. Since you are not copying the image file from your phone to your PC and then transferring the image file to your Dropbox account but instead going from your phone to your Dropbox account (your PC is not involved in the transfer), in what timezone is the Dropbox server? I used the Dropbox client on my PC for a few years but stopped when its paltry free quota of 2 GB was long surpassed by my OneDrive (25 GB) and Google Drive (15 GB) accounts. As a consequence, I had no interest in the Dropbox app on my phone. I don't recall configuring to where the Dropbox client connected. It figures that out or hits a front-end (boundary) server to their mesh network of file servers. http://www.datacenterdynamics.com/co...90.fullarticle Maybe your files are on a German data center's file server contracted for service by Dropbox. Germany is UTC +1 whereas you are UTC +0. Maybe you could figure out to where your Dropbox client connects that is running on your PC, or to where the Dropbox app on your phone connects for where it stored your files. https://www.dropboxforum.com/t5/Inst...amp/td-p/12574 Without a change in the file to overwrite the old version on the server, the timestamp for the old one on the server won't change. The local file (on your PC or on your phone) would have to change for the Dropbox client there to send a new copy of the file to the server. https://www.eldos.com/forum/read.php?FID=7&TID=6239 I've seen similar posts about mismatched timestamps when using Google Drive (i.e., file's timestamp on the server does not match the local time where the file was created and then uploaded). https://www.jotform.com/answers/2908...-my-local-time That's pretty old (over 3 years ago). I don't remember seeing that timezone setting in the Dropbox client that ran on my Windows 7 host. However, I rarely visited their web site to view my account up there. Mostly I just used their local client and only logged on to the online account to verify my files got up there. Once I had done that a few times and verified the sync was working, I didn't bother connecting to my online account via web browser anymore. |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Irfanview EXIF time from iPhone photos? | Terry Pinnell[_2_] | Digital Photography | 1 | May 2nd 16 04:45 PM |
Exif date and time change | Dimitris M | Digital SLR Cameras | 12 | September 16th 09 05:25 PM |
Modifying Canon RAW EXIF time-taken | Robert Coe | Digital Photography | 0 | March 14th 09 12:28 PM |
Modifying Canon RAW EXIF time-taken | Ricky H | Digital Photography | 1 | March 11th 09 04:25 AM |
Modifying Canon RAW EXIF time-taken | Hans Kruse | Digital Photography | 0 | March 10th 09 11:08 AM |