# XMP Files?



## mcoppadge (Aug 11, 2009)

After editing some photos on Photoshop, I found a bunch of .xmp files in the same folder. Can someone enlighten me as to what these are? Can I get rid of them?


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## Josh66 (Aug 11, 2009)

mcoppadge said:


> Can I get rid of them?



You can, but then you will use all of your work.

They are the sidecar files that tell PS what to do to your picture.

When you edit, it's not actually changing the picture.  It's just writing a file (the .xmp sidecar) that tells it what to do when you export it.


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## mcoppadge (Aug 11, 2009)

Are they associated with a certain filetype?


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## Josh66 (Aug 11, 2009)

What do you mean?  They _are_ a file type.

Do you mean a certain program?  As far as I know only PS or LR can read them.


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## Josh66 (Aug 11, 2009)

Think of it as a log of all of the changes you have made to a picture.


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## mcoppadge (Aug 11, 2009)

I mean are they created whether or not you're editing JPGs, TIFFs, or RAW?


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## Josh66 (Aug 11, 2009)

Yes, they get created no matter what kind of file you are working on.

That's the case with Lightroom anyway, I would think Photoshop would be the same.


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## mcoppadge (Aug 11, 2009)

Great. Thanks!

I use Extensis Portfolio to catalog my photos and I kept finding .xmps in my catalog and didn't want them there. I figured out how to get Portfolio to ignore them so it doesn't really matter anymore. At least now I know what they're for.


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## Peano (Aug 11, 2009)

mcoppadge said:


> Are they associated with a certain filetype?



Yes, they're associated only with raw filetypes ... .NEF in your case, .CR2 for Canon raw files, etc. They contain instructions for the changes you made in your raw converter, not changes you made inside Photoshop. So if you move a raw file to a different directory, you should move the .XMP file along with it.

If you don't want Camera Raw to create .XMP files, you can change that in the preferences dialog. But you're probably better off to keep saving changes in .XMP sidecars.


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## Peano (Aug 11, 2009)

O|||||||O said:


> Yes, they get created no matter what kind of file you are working on.



No, they're only created for raw files, not for .DNG or .TIF or .JPG, for instance.


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## Josh66 (Aug 11, 2009)

Yes, they are created for JPGs and TIFFs in Lightroom - like I said.


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## Peano (Aug 11, 2009)

O|||||||O said:


> Yes, they are created for JPGs and TIFFs in Lightroom - like I said.





O|||||||O said:


> That's the case with Lightroom anyway, *I would think Photoshop would be the same*.



It isn't the same in Photoshop/Camera Raw.


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## iflynething (Aug 11, 2009)

I have never actually tried to open one though, gonna try it now though

~Michael~


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## UUilliam (Aug 11, 2009)

.xmp is a virtual backup copy of your RAW file so it doesn't destroy your raw file when editing, If you dont want your changes to be saved, delete them or if you saved the changes as .jpg then delete them if you want.


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## iflynething (Aug 11, 2009)

I have always deleted these files. EVERY time.

If they are back-up to the RAW files, then why are they only under 10kb? I right clicked it and selected to open in PS but nothing happened?

~Michael~


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## Josh66 (Aug 11, 2009)

It's not a back-up.

It records what you did to the RAW, since you can't actually alter the RAW.

Edit one of your RAWs.  Close PS, open it back up.  All of your changes are still there.

Now, edit one, close PS, delete the .xmp file.  Open PS back up.  All of your edits are gone, you have to start from scratch on the RAW.


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## iflynething (Aug 11, 2009)

OOOOOOOOH, that make sense.

I have never needed to "redo" or figure out the same settings I used. Once I edit a RAW file once and set the WB, Exposure, etc. I save that as a JPEG and edit that unless the editing is going to be heavy

~Michael~


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## UUilliam (Aug 12, 2009)

In that case you can go ahead and delete the .xmp
the XMP basically records your edit history then re applies it each time you open your raw
only keep it if you plan on editing the raw later and you want to keep it the same as last time


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## KmH (Aug 12, 2009)

iflynething said:


> OOOOOOOOH, that make sense.
> 
> I have never needed to "redo" or figure out the same settings I used. Once I edit a RAW file once and set the WB, Exposure, etc. I save that as a JPEG and edit that unless the editing is going to be heavy
> 
> ~Michael~


One of the major advantages of a RAW or TIFF file is that it's 16 bit depth file. JPEG has only an 8 bit depth.


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## Josh66 (Aug 12, 2009)

As small as the .xmp is, I don't really see any reason to delete it.
(I just opened up one of my folders just to double check - looks like they're all about 12 KB.  I'm not too worried about that.)

I always keep mine, just in case.

There have been a few that I decided to tweak months after I originally processed it.
Having to start from scratch, while not impossible, would have been an inconvenience.


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## UUilliam (Aug 12, 2009)

KmH said:


> iflynething said:
> 
> 
> > OOOOOOOOH, that make sense.
> ...



actually most RAW is only 12bit - 14 bit
but it gets used as a 16bit image
But there is camera's out there that can record 16 bit and possibly soon 32 bit.


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## KmH (Aug 12, 2009)

UUilliam said:


> KmH said:
> 
> 
> > iflynething said:
> ...


True, Nikons record 12 bit and some Canons record 14 bit. The extra 2 or 4 bit positions are ignored, but there is still a big advantage to having 4096 color variations per channel (12-bit) rather than 256 per channel (8-bit).


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