ExifTool Forum

[Originally posted by multcam on 2009-10-31 14:26:11-07]

I forgot setting my camera time back to wintertime. So I used the command

This works very well, except before I issued this command when viewing .CR2 files with IrfanView I saw the picture big (1536 * 1024). After issueing the command above I see the same image very small in IrfanView (160 * 120).

I use the "I" option to get information about the picture.

Yet I only want to change the dates with -1 hour.

What is happening? Why is the image changed when viewing with IrfanView?

I use a Canon 350D camera and the image is shot in RAW.

[Originally posted by exiftool on 2009-10-31 17:55:46-07]

I suspect that IrfanView may be using some quick-and-dirty logic
instead of properly parsing the file to locate the preview image.

I suggest sending a sample image to the IrfanView developers and
asking them why they can't display the big preview image.  I assure
you that it is still there.

- Phil

[Originally posted by multcam on 2009-11-02 17:20:13-08]

Hi Phil,

Thank you for your answer. I'm afraid if I go to IrfanView they will say that it is because of the change in the metadata. Since before issuing the Exiftool -alldates command I see the picture correctly.
Only after I issue Exiftool -alldates IrfanView shows it very small. So the only change made to the file is the ExifTool -alldates command.

Can you think of what could have happened?

Dick

[Originally posted by exiftool on 2009-11-02 18:04:49-08]

I've seen similar things before with other applications.  Like I said,
my guess is that they are taking some shortcuts when parsing
the file to location the preview.  Perhaps they are assuming that the
preview is at a constant offset in the file.  If this is the case, a
camera firmware update could also cause similar problems for
IrfanView. (I have seen this happen before too for other software.)

- Phil