# Mac OSX (mojave) Finder cannot show DNG files



## dwatkins54 (Jul 9, 2019)

I'm experimenting with DNG and deciding if I will use them.  Mostly I'm convinced that I should, however, as my title suggests, the finder (and snapshot, open dialogs etc) can't show thumbnails (i'm trying not to use the word preview here to avoid confusion ) ... . I've googled for solutions but haven't found any as yet ... anyone know if this is solvable ?

Dave


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## Califdan (Jul 10, 2019)

Not a Mac user, but for Windows there are OS Plugin's called CODEC.    Google "DNG Codec for Mac Mojave"

Pros and cons of DNG.  I used to import my RAW files as CR2's (Canon RAW).  Then switched to DNG for about 5 years.  Then switeched back to CR2.  
*
REASONS I WENT TO DNG*
- DNG's are about 20% smaller than the corresponding CR2
- DNG's can absorb metadata and develop changes inside the DNG file itself without the need for seperate XMP (side car) files
- DNG's contains same quality and information as CR2's (as far as I can tell) - even focus point information that LR does not utilize
- DNG's are less proprietary than Camera RAW files and are then less vulnerable to corporate die off

*REASONS I WENT BACK TO CR2*
- 20% larger files not that big a deal with how inexpensive disk drives and memory cards have become
- CR2's store metadata and develop changes in XMP side car files
- Canon and Nikon are not likely to go out of business anytime soon and even if they do, there will be plenty of time to convert CR2's to TIff or DNG or something else if that time should ever come.

OK, so why were XMP files an attribute for DNG's but then became a detriment?   This is the main reason I went back to CR2's.   With "Automatically Save Metadata Changes to XMP files" turned on in LR, every time a made any change to an image metadata (e.g. changed star rating, changed title or caption, adjusted keywords, etc.) it had to rewrite the entire twenty something megabyte file (or at least part of the file).  This wasn't too bad as LR did it in the background but then my backup SW saw that the file had changed which required it to be re-backed up.  My evening backups were running hours and hours and eventually all night copying all the modified large DNG files and my cloud backups were never catching up (newer block level backup tools may accommodate this better).  Whereas with CR2's the only thing changed by LR are tiny XMP files which backup quite quickly compared to DNG's.


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## Jim Wilde (Jul 10, 2019)

dwatkins54 said:


> I'm experimenting with DNG and deciding if I will use them.  Mostly I'm convinced that I should, however, as my title suggests, the finder (and snapshot, open dialogs etc) can't show thumbnails (i'm trying not to use the word preview here to avoid confusion ) ... . I've googled for solutions but haven't found any as yet ... anyone know if this is solvable ?
> 
> Dave


What camera are the DNG files from? My Mojave system has no problem with showing the thumbs for my DNG files in Finder, but I think it depends on the camera that produced them. I don't recall having to take any specific action, Apple periodically updates things to add new camera support. I vaguely remember I had a similar problem initially with the files from my Olympus E-M1 II which was resolved with a later OS update.


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## clee01l (Jul 10, 2019)

Jim Wilde said:


> What camera are the DNG files from? My Mojave system has no problem with showing the thumbs for my DNG files in Finder


I have some Pano DNGs created by Lightroom.  MacOS  Mojave does not have a Codec capable of extracting the thumbnail.  I also have some HDR DNGs that do show a thumbnail.


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## dwatkins54 (Jul 10, 2019)

Thanks for the replies. I think I may have the issue partly solved or at least narrowed down.  
Jim your answer put me on track. DNG files created from ARW (my Sony A7iii)  are viewable in finder etc.  However the DNG files I created from TIFF (using LR) are not...   I found a comment on the adobe forum that also noted the same behavior. 
So perhaps I'll just leave the TIFs alone... which seems like a good plan based on Califdan's response


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## Johan Elzenga (Jul 10, 2019)

Why would you create a DNG from a TIFF in the first place? That does not serve much purpose.


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## dwatkins54 (Jul 11, 2019)

Johan, you're right... I was being geeky and figured having ALL my files as DNG was neater.  I did some more experimenting and HEIC converted to dng also doesn't show up in finder..... so, i'll put my geek/ocd aside and leave files in their "birth" format


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