[Digikam-users] Time & Date (Original) seconds value

[Jean-François Rabasse]

Hi Mick,


On Tue, 26 Feb 2013, Mick Sulley wrote:

> The EXIF data displayed on the right hand panel shows Date and Time 
> (original) as date plus time in hours, minutes and seconds.  When I try to 
> edit EXIF data I can change the date and the hours and minutes, but there 
> does not seem to be any way to change the seconds.
>
> Is there a way to edit the seconds?
>
> The reason for this is that I use date and time to rename pictures, and I 
> have some that were shot with APS film, then processed to CD, and all 
> pictures have 00 as the seconds, so I am getting duplicate file names where 
> multiple pictures were taken within the same minute, so I want to edit the 
> seconds on these files.
>
> Also there is a tick box and field for Original sub-second, what does this 
> mean?  I cannot find it in the manual.

Sub-seconds is an Exif tag that has been added to allow a more accurate
time definition that the second.
The reason was that standard Exif DateTimeOriginal (tag 0X9003) is a 
text field limited to 20 characters including a trailing zero.
So you can store 'YYYY-MM-DD HH:MN:SS', 19 characters, nothing more.
The subseconds adds a decimal part to seconds, SS.nnn

But as far as I known, very few software handle that and in most cases,
one needs to process such kinds of renaming 'by hand', with command line
tools.

Anyway, renaming based on datetime stamp only may not be always a good
strategy. If you edit seconds, you'll solve your immediate problem, yes,
but there are several cases where renaming - even with valid seconds -
will produce duplicates. E.g.
- images shot with the camera in burst mode. Most cameras can record 3
or 4 images per second.
- images collected from several cameras and users. (Typical case is some
social event as a wedding. When the bride and bridegroom say Yes, it 
last 10 seconds and when you are the one in charge of the photos 
albums, you often collect 150 images from all the guests, for that 10 
seconds:-)

Why not considering adding a sequence number after your date ?

Regards,
Jean-François