Sorting Pictures

alain38330

Bonjour
First I apologize for my English
I am new with using Tonfotos and a bite lost due to the lack of user guide or even some basic information.
One thing I need to understand is the way Tonfos is sorting the images in the different folders which then lead to how the images are shown in the slideshow sequence
It seems to be by date/time when the image has been created…but not only…
I have been mixing in the same folder pictures taken by 3 different cameras used on the same event (a wedding event).
In Windows, images are perfectly sorted through the time of creation (local time) and slideshow is showing things one after the other in de right order.
In Tonfotos it is a mix of groups of pictures. Within each group the pictures are shown in the correct order but the groups themselves are not in the correct sequence.
I also noticed that some groups are belonging to 2 cameras (correctly mixing their pictures) while the other groups are all belonging to the 3rd camera.
I then looked into the Exif data of pictures from the 3 cameras: they all show correct create date/time but one camera (more sophisticated) is showing additional Exif data: a “gps time stamp (UTC)” and also some “Offset time” Exif tags.
In my opinion it is this 3rd camera which is providing pictures not merging correctly to the others one
It seems to me that Tonfotos is using (when available) either Exif GPS time data or TimeZone adjustment data or Summer/Winter shift data to adjust the “Created Date/Time” only for the purpose of sorting the pictures

Could someone explain to me “the mystery” of the sorting method of Tonfotos wich in my case is causing a very serious issue as I did not found yet any sort parameters in Tonfotos to get pictures arranged in each folder just simply by the time they have been taken?
Merci
Alain

Andrey

alain38330 I’m afraid, right now there is no control over sorting in Tonfotos inside displayed folders. However, this is one of the most requested features and is in our roadmap.

As to slide shows, you would have much more control over sequence if you would use Albums. Files are displayed in album strictly in the order you added it there. So you can just create your own slideshow sequence by adding images in the order you want then to be displayed. Then you just start your sildeshow not from the folder, but from the album.

I hope that makes sense.

alain38330

Merci Andrey for your prompt answer.
Regarding the pictures of the 3rd(sophisticated) camera I have been substracting 1 hour to the Exif “DateTimeOriginal” (Exif Tag &H9003) and now the pictures are merging perfectly.
All these pictures contain an Exif OffsetTimeOriginal (Tag &H9011) which is related to the time zone for the DateTimeOriginal and which is containing in my case the value “+01:00” hour.
So to think this number was added to the DateTimeOriginal in the sorting process would explain all the story.

This being said I feel there are promising features in Tonfotos and a good user guide is becoming a must.
Alain

Andrey

alain38330 Thank you. We are working on the text guide, please stay tuned.

As to time zones, you are totally right, Tonfotos preferres GPS time as there is no confusion with time zone in that case, it always in UTC. While there are lots of images when time zone is just not set so all we have to guess which time zone it could have been. When there is no TimeZone we default to current one (one set on this PC).

alain38330

In theory this is perfect choice; practically as far as the time in the camera is closed to the one of the arm-clock it’s ok and this can be done without caring of timezone… which is what happened to me.
Maybe when developing sort options in Tonfotos, one option on LOCAL OriginalDateTime could be considered

Andrey

alain38330 I am not sure I fully understand the issue. If you believe that Tonfotos wrongly interpreted the time in the photo metadata then this is bug and we will be happy to fix it. I would appreciate sending sample images to support@tonfotos.com in that case, as well as more detailed description why you think this was wrong.

If the issue in on the side of the camera - then Tonfotos is offering easy way to fix that. Using this function you can correct the time zone for all pictures at once.

alain38330

Late answer, I was traveling.
The issue is related to the setup of the timezone in the camera and not in Tonfotos.
When traveling (eg: accross the USA) you can very well setup a correct new local time in the camera without touching the timezone setup. Then the Exif OriginalDateTime (the one the user will see) will be correct but the UTC one as calculated back by Tonfotos will be wrong…if I correctly understand the calculation by Tonfotos…
Alain

Andrey

alain38330 We have tested time calculation by Tonfotos on multimple images so it is a bit hard to accept it is incorrect. I would appreciate if you would share specific examples of the EXIF field values with your explanation why you thing we calcluate it wrongly.

alain38330

Andrey, I may not have expressed correctly what I wanted to tell and I apologize for that:
I am not telling the calculation done by Tonfotos is wrong, I am telling that if the user is keeping for example a wrong timezone but is setting a right DateTime in his camera then the pictures will show the right DateTimeOriginal but the calculation will take in account a wrong offset to this rignt DateTimeOriginal and will comeup with a wrong UTC time.
Sh..in, Sh..out as we used to say!

I am probably a bad user because going time to time to Montreal QC I never changed my Paris timezone in my camera I just setup a new time by substracting 6 hours (not sure to be alone doing that).
All my pictures are merging perfectly with the one of my Canadian friend, based on the DateTimeOriginal but when calculating the UTC time from a Montreal correct local time by applying the timezone adjustment of Paris will lead to an error…and merging pictures based on this will show wrong sequence.

To answer your question, in my case I have been looking to pictures from 3 o 4 camera sources with the “Exiftool” program mainly: Tag DateTimeOriginal 0×9003 and Tag OffsetOriginalTime 0×9011,
If I remember correctly, one of the cameras was showing a value of 2 (I presumed 2 hours) in the Offset and the other cameras were not showing any Offset Tag… but all of them were showing the right DateTimeOriginal and this is the reason why I though I had issue sorting on UTC.

This is my current understanding and I may be totally wrong.
I hope having clarified a little bit my story

Alain

Andrey

alain38330 Thank you very much for detailed explanation, I understand now. Good news is, you can easily fix that with Tonfotos. You can shift all photos in time for necessary amount of hours using same F3 function. And you can change time zone at the same time. Just select all such photos, press F3, adjust time and zone, and make sure “shift all photos…” option is selected, that should do the trick.