ExifTool Forum

[Originally posted by helpless on 2009-02-22 08:12:20-08]

Exiftool seems to be a great program, but it's just so complicated. All I need to do is to change the "Focal Length" tag in the exif of a .JPG file since my software (PSP Photo X2) resets the Focal Length to 0.00mm on some files when saved (I think it's a bug). I'd be greatful for a "step guide" for how to do this. I have a Canon EOS 50D. The program Exiftool is in the same dir as the file I want to change. Thanks in advance!

[Originally posted by bogdan on 2009-02-22 12:00:28-08]

Hi,

Try with:

exiftool -exif:FocalLength=50 MyImage.tif

Above works, but there's a problem I've noticed when using PSP X2 (v12.5). That is, PSP doesn't save Makernotes as it should (that is: Makernotes section is somewhat corrupt).

Because of that, exiftool will (by default) refuse to write into such image file. To make writting possible, you should use:

exiftool -m -exif:FocalLength=50 MyImage.tif

-which ignores "m"inor errors and thus writes metadata

Of course, you can delete complete existing Makernote section (it became useless anyway) and write FocalLength as shown in first example.

Greetings,

Bogdan

[Originally posted by exiftool on 2009-02-22 12:13:38-08]

There are a few different ways to do this, and the step-by-step
instructions depend on what operating system you are using
and what method you want to use.
If you are running Windows, then maybe the easiest thing
to do is to just rename the "exiftool(-k).exe" program to
something like "exiftool(-k -focallength=50).exe", then
drag and drop the image(s) onto the icon for the program.
(Use whatever focal length you want in place of "50" here.)

Doing this will open a terminal window which will show
any messages from exiftool.  As long as there were no
errors, then the file should be updated to contain the
new focal length, and the original image is backed up
with a "_original" added to the file name.

Note: Don't add the ".exe" to the program name if it wasn't there
before, because the extension is hidden in some Windows
systems and it won't work if you add a 2nd one.

Good luck.

- Phil

[Originally posted by exiftool on 2009-02-22 12:18:45-08]

Hehe.  Bogdan typed faster than me this time.

I told you there was more than one way to do it.

Bogdan is running the command from a terminal window
(select "Run..." from the Start menu, and type "cmd" for
the command to run -- this will open the terminal window.)

I didn't suggest this method because it is more involved.
Before typing the exiftool command that Bogdan indicated,
you first must use a "cd" command to change the current
directory to the one containing exiftool and your image.

- Phil

[Originally posted by igor77 on 2009-02-22 19:36:37-08]

Hello!

May be it is possible and more convenient to copy Focal Length into file before use PSP and after using it return this tag into file. May be XMP file - I'm not specialist. This way we can save real Focal Length, not only 50 mm (or other one).

Igor

[Originally posted by helpless on 2009-02-23 09:34:20-08]

I managed to get it work not that long after I wrote this thread. This is the string that worked: exiftool -FocalLength="250" test.jpg. One file got updated and so did the Focal Length! I'm running Windows XP and renamed the program to exiftool.exe to run with command line. Thanks guys -- and thanks for ExifTool!!