While I don't have a list (would like to see one though!), some
editors do lose the EXIF data while others preserve it. Then,
there is the argument I have heard that if the image is modified,
the EXIF is no longer valid so should be discarded -- my pref
would be to see an editor that when you modify an image, leaves
the original EXIF data, but adds a comment in the comment
field "modified and the date". Some editors advertise they
preserve the EXIF data others are silent. Get a utility like
irfanview (free) http://www.irfanview.com and use it to see
what the EXIF data is (good program for other stuff too).
I guess the bottom line is, yes, it is a crap shoot and you need
to test all of your software used in modifying images to see
which ones trash the EXIF data for you. I also like to keep
the originals -- disk space is cheap these days (and make
backups, but that is another thread in this group !! )

mikey

"Terry Pinnell" wrote in message
...
I suspect I'm being unduly optimistic in hoping this is a question
with a relatively simple answer!

When I browse folders of old photos, I would often like to know the
precise date and time they were taken. But the EXIF data is missing
for many. Presumably EXIF info must have existed for *all* of them
when I first downloaded the DSC000xxxx.jpg images from my Sony
Cybershot DSC-1 to my PC, but editing has destroyed it?

Does anyone have or know of an up to date list of all operations by
specific graphic editing programs which result in such destruction of
the EXIF data please, so that I can make a point of avoiding them?

Am I right that although Operation X in Program A might preserve EXIF,
Operation X in Program B, or Operation Y in Program A (etc) might
destroy it? IOW, it's something of a mess? If so, I guess the safest
bet is to keep a copy of those originals, or at least a compact list
of some sort of their EXIF dates, for future reference if it's
inadvertently lost?

--
Terry, West Sussex, UK