# Should I convert jpg to DNG



## tvds (Aug 21, 2008)

Okay....
The last few months I have scanned over 4''' old photo negatives.

I want to put these in lightroom.

Should or Shouldn't I convert these jpg's to DNG ?

I want to be able to work on them with out distroying the original.
So then I would be yes right ? Or not.

I hope you can tell me, what is right.

The jpg's are high quality minimal compression files.

Thanxs


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## ndtking (Aug 21, 2008)

I believe the jpg format should make no difference as far as image quality - the lightroom adjustments are non-destructive and are only fully applied when you export.  So the issue of deteriorating jpg quality shouldn't apply. (Someone please correct me if I'm wrong...)  When you export you are not altering the original in any way. (unless you happen to export into the same directory with the same name, and even then you should get a dialogue asking you if you want to overwrite.

So the only issue is if the DNG format will work better for you for other reasons.

BTW, I have scanned a number of old film shots over the last few years (quite a few of those slides taken by my parents starting in 1946-7), most of them done before I had Lightroom.  I scanned most of them with 14 bit colour using the highest resolution and saving to TIFF.  File sizes were anywhere from 5'MB up to 16'MB!!


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## johnbeardy (Aug 21, 2008)

I don't think it's worth it unless you (a) don't have backups (b) really think it likely you will overwrite the original by editing it in Photoshop. 

Converting JPGs to DNG may help you identify them as originals, and will prevent overwriting. You can also update the edited preview, and always be able to reverse that work, and this might be handy if you're using other applications which read DNGs.

A downside is that right now converting a JPG to a DNG greatly increases file size (it holds the image data as 16 bit). 

There are more benefits converting raw files to DNGs.

John


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## Brad Snyder (Aug 21, 2008)

tvds and ndtking, Welcome to LR Forums.

tvds, I second (third?) the two responses. Nothing realy to be gained in your situation by converting to DNG. The result you want will also work with JPG. 

I would verify the following settings in LR:

Library menu > Edit > Catalog Settings > Metadata tab , enable these two
store adjustments in JPG, TIFF, etc ....
Autowrite XMP ....

See attached:


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## stasber (Aug 21, 2008)

And how would I go about converting a JPG to a DNG in LR if I wanted to?

Every time I've tried to convert on import, I get a message telling me something like no files were converted to DNG or couldn't convert to DNG, leading me to think that the only valid format for conversion would be a RAW format. The JPGs have different origins, some from a Canon DSLR, others from various digicams.


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## Brad Snyder (Aug 21, 2008)

Stas, see attached

This is for jpgs already in the catalog. I get the same 'not converted' message, when trying to convert on import. I'll have a further look at that later.


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## tvds (Aug 21, 2008)

ndtking;2'14' said:
			
		

> File sizes were anywhere from 5'MB up to 16'MB!!



Wow.... 5' tot 16' MB.... did not put them into Tiff yet  Than I rather put them in DNG


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## tvds (Aug 21, 2008)

stasber;2'157 said:
			
		

> And how would I go about converting a JPG to a DNG in LR if I wanted to?



Strange, in Lightroom 1.' I once did a convert to DNG, and it worked like a charm.

These JPEGs or not from a camera but from an scanner output. Canon to be exact.

I do think I will convert them to DNG, I will let you know if it worked.


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## tvds (Aug 21, 2008)

johnbeardy;2'146 said:
			
		

> There are more benefits converting raw files to DNGs.


John,
Okay, so you say don't do this.
As the org files will stay untouched.

That seems good then.

Thanxs


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## tvds (Aug 21, 2008)

Brad Snyder;2'15' said:
			
		

> I would verify the following settings in LR:
> 
> Library menu > Edit > Catalog Settings > Metadata tab , enable these two
> store adjustments in JPG, TIFF, etc ....
> Autowrite XMP ....



Brad,

Thank you for that tip !

I will import them as JPG and not convert them into DNG

Thanxs all !

Kind regards

Theo


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## stasber (Aug 22, 2008)

Brad Snyder;2'161 said:
			
		

> Stas, see attached
> 
> This is for jpgs already in the catalog. I get the same 'not converted' message, when trying to convert on import. I'll have a further look at that later.


Brad - many thanks for that, I hadn't tried  images already in the catalog. It does work for images in the catalog - I was able to convert a JPG and a TIF.

However it seems to be on a per-instance basis. The 'convert non-raw' option seems to re-select itself each time. This may also be preventing the conversion at import. Not sure if this is by design or an oversight - as there is no access to this option at import.


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## tvds (Aug 22, 2008)

*not*

Tried to import jpeg as DNG...

Did not work, tonight I will try to convert a few jpg's to dng after export.


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## tvds (Aug 24, 2008)

I have another question about DNG.

If I want to have metatags and other extra information in my jpeg files... than I shouw convert to DNG right ?


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## Brad Snyder (Aug 24, 2008)

That will really depend on what software you intend to 'read' the metadata with, and whether you intend to 'export' the jpgs or just use them internally with LR.

What do you want accomplish?


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## tvds (Aug 25, 2008)

Brad,

Well what I hope for is that more and more software is able to display or read dng files and then they will also be able to read the tags in the dng files.

So not only LR is able to search through the tags but also let's say picassa or flickr.

I never understood why camera manufactures like canon did not put this into their raw files. You know like MP3 tags. You can put so much information in a MP3 file, why is that not possible in most raw files.

Now with DNG this is possible (well for some metadata which I understand)

I would like that for all my photo's.


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## Brad Snyder (Aug 25, 2008)

Well, that's a good wish. The only thing that I can add, is that the state of the art of image (actually, all media) metadata is changing fairly rapidly, and the combination of new standards, and existing legacy standards is causing a lot of incompatibility problems between applications from different vendors. 

Probably, exported jpg files will be the most compatible between applications, but then that causes you to duplicate your library in both raw/DNG and JPG, and adds a synchronization problem.


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## Victoria Bampton (Aug 27, 2008)

Yep, I'd stick with jpegs with updated metadata (Ctrl-S/Cmd-S) for now, if they started out as jpegs, and consider DNG for raw files.  There are still a lot of programs out there that can't read DNG yet, so I wouldn't discount jpeg quite yet.


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## wcm49 (Aug 28, 2008)

Why would you not scan the images as TIFF to start with? You avoid all of the problems with jpg from the git-go and have a much better format to work with.


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## Brad Snyder (Aug 28, 2008)

wcm, welcome and thanks for the advice.  Unless storage space is at a huge premium, what you say is certainly valid. 

All of the metadata advice still applies, tho', I'd say.


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## tvds (Sep 2, 2008)

Okay, so Tiff. But if tiff, why not DNG.

Yes I understand not all software can handle DNG. But I think everything will go to DNG right ?

So more and more software will be able to handle DNG.


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