IPTC, EXIF, XMP?

I am somewhat familiar with IPTC information for images and using various programs to edit it and that some programs (photoshop) use XMP files for other data. Is EXIF pretty much the same as IPTC?

Should I be concerned if a program can only uptate IPTC/EXIF data? Is it important to also manage the XMP files?

I don't know much about IPTC, that seems to be textual descriptions of the photos that you can enter. EXIF contains technical data, like shutter speed, aperture, the name of the camera owner, etc. I think you can bung other stuff in too.

XMP is a meta-data file for RAW files that Adobe creates, things like your settings for exposure, curves, shadows, etc are stored in there. I wouldn't be suprised if IPTC data's stored there either.

If you want a good book on RAW try this one, it's great.

EXIF is metadata that, for most users, is NOT editable, just readable. [Though there are a few prograams that let you change file creation data if the camera was set wrong, etc.]

For most practical purposes and users embedding metadata, IPTC will = XMP.
E.g., to put IPTC in iView or PhotoShop, we use XMP Templates.
XMP is Adobe's extensible, open, implementation, by which they enable embedding IPTC plus many other kinds of metadata in file headers, like RAW conversion history. You can write it and read it.

There are many reads on the subject if you search.
J.

Humm. I answered that ... poorly.

Here's Canon's publication on the subject. A very nice read.
http://postit.rutgers.​edu …aData%20EXIF%20​IPTC%2Epdf

Jack

Thank you all,

I do have the camera raw book. It is excellent. The Canon pub was interesting. I would guess that it is the IPTC info I should be more concerned about updating.