Finder / Quicklook / Preview can not view DNG files?

[Dochartaigh]

My google-fu might have failed me... but DNG is a pretty standard file format now – how can I hit spacebar in Finder and see a preview of these images? They're industry-standard Adobe DNG's - nothing special or weird about them.

 

[NoBoMac]

From what I've read, can be hit and miss, depending on camera, tools used, workflow.

Was able to QuickLook a Leica DNG file I found on the interwebs. Latest Ventura.

 

[Dochartaigh]

From what I've read, can be hit and miss, depending on camera, tools used, workflow.

Was able to QuickLook a Leica DNG file I found on the interwebs. Latest Ventura.

So I guess Leica uses .DNG file name for their .RAW files? Makes sense, and DNG's are "Digital Negative" files... My Finder will preview my Sony .ARW camera raw, my old Canon .CR2 raw, will NOT open Nikon .NEF files... and of course will not open Adobe .DNG's....

So this is literally Apple screwing INDUSTRY STANDARDS... and their machines have always been geared towards creatives so I don't get it... so how does one add a file format to be previewed? Like I said, I can't find this info on Google so any info is appreciated.

 

[gilby101]

So I guess Leica uses .DNG file name for their .RAW files? Makes sense, and DNG's are "Digital Negative" files...

DNG "format" is a container - so much depends on what is inside.

On my Mac, Preview and Quicklook are able to display most DNG files, but not all. I only have about 1000 DNG files, and the few which can't are RAWs from open source non-Canon software in a non-raw Canon Powershot S3 IS. But all are readable by Graphic Converter, Affinity Photo or Photoshop (but not PixelmatorPro)

So this is literally Apple screwing INDUSTRY STANDARDS...

Adobe DNG is a standard available to anyone, but how it is used may not be part of the standard.

Not deliberately. Apple does not include all formats which might be inside DNGs. For cameras RAWs packaged as DNG, Apple may be deliberately leaving it to camera manufacturers to provide the necessary. In some case there may be legal reasons - e.g. the camera manufacturer only makes format available to purchasers of their cameras.

so how does one add a file format to be previewed?

Can you give a description of one that can't be previewed? Even better a link to an example.

 

[Dochartaigh]

DNG "format" is a container - so much depends on what is inside.

On my Mac, Preview and Quicklook are able to display most DNG files, but not all. I only have about 1000 DNG files, and the few which can't are RAWs from open source non-Canon software in a non-raw Canon Powershot S3 IS. But all are readable by Graphic Converter, Affinity Photo or Photoshop (but not PixelmatorPro)

Not deliberately. Apple does not include all formats which might be inside DNGs. For cameras RAWs packaged as DNG, Apple may be deliberately leaving it to camera manufacturers to provide the necessary. In some case there may be legal reasons - e.g. the camera manufacturer only makes format available to purchasers of their cameras.

Can you give a description of one that can't be previewed? Even better a link to an example.

Inside are simple, normal, garden variety JPG's (which I'm doing some camera raw stuff to after -haven't touched them yet- so wanted them in a digital negative format which works well for my workflow). Finder can of course preview the JPG's outside of the DNG container, just not once it's inside.

Here's a link to one: https://www.mediafire.com/view/ehet9tvx7qjnq5m/IMG_2032.dng/file

 

[gilby101]

Here's a link to one: https://www.mediafire.com/view/ehet9tvx7qjnq5m/IMG_2032.dng/file

I can open it in Adobe Camera Raw and then Photoshop. Graphic Converter says "The TIFF internal directory is corrupt; the file cannot be opened."; but does show me a thumbnail. So I am not surprised Preview fails.

So I am guessing there is something non-standard (or at least uncommon) inside the DNG. Am I right in understanding that you have constructed the DNG? File Info says it is from a Canon PowerShot SD500, but I assume that is just from the JPG inside the DNG files.

Can't do more right now. Will look further tommorow. Or, better, someone more expert than me can give you hints.

 

[Dochartaigh]

I can open it in Adobe Camera Raw and then Photoshop. Graphic Converter says "The TIFF internal directory is corrupt; the file cannot be opened."; but does show me a thumbnail. So I am not surprised Preview fails.

So I am guessing there is something non-standard (or at least uncommon) inside the DNG. Am I right in understanding that you have constructed the DNG? File Info says it is from a Canon PowerShot SD500, but I assume that is just from the JPG inside the DNG files.

Thanks for looking! And no, these are as common as they get - old JPG's from probably the best-selling point-and-shoot camera product line ever, Canon PowerShot. To make them into DNG's I use either Adobe Bridge or Adobe Lightroom Classic "export to DNG" - also super industry standard.

Other .DNG's are from (old) JPG scans from Photoshop, converted the same way as above - also can't open those.

For something more modern, (Adobe developed this .DNG file format btw), here's a Sony A6000 image (probably tied with Fuji for the best-selling APS-C mirrorless camera in existence) in .PSD, .TIF, and .JPG format - ALL preview in finder correctly. I then exported a .DNG of all of them - all 3x will not preview:

DNG

MediaFire is a simple to use free service that lets you put all your photos, documents, music, and video in a single place so you can access them anywhere and share them everywhere.

www.mediafire.com

P.S. I'm just making all these "best selling" and "industry standard" references to really hit the point home that these are TOTALLY NORMAL files! In super duper common use everywhere... and Apple still can't preview them!

 

[gilby101]

And no, these are as common as they get - old JPG's from probably the best-selling point-and-shoot camera product line ever, Canon PowerShot. To make them into DNG's I use either Adobe Bridge or Adobe Lightroom Classic "export to DNG" - also super industry standard.

I can reproduce what you are seeing. When I use Lightroom to export as DNG with input files either PowerShot jpeg or CanoScan tiff. The DNG can't be opened with Preview, but can with Affinity.

I have no such problem with DNG exported from Canon RAW.

I note that Adobe DNG Converter refuses to attempt JPEG to DNG.

I don't know enough about the DNG format as to what is allowed inside an DNG. I can see the logic of not converting JPEG to DNG, because DNG is intended for RAW formats and it is somewhat meaningless to convert a JPEG to a RAW format.

 

[Dochartaigh]

I can reproduce what you are seeing. When I use Lightroom to export as DNG with input files either PowerShot jpeg or CanoScan tiff. The DNG can't be opened with Preview, but can with Affinity.

Thank you for testing. And yeah, it seems to be pretty willy-nilly what it will actually preview... just makes it annoying that I have to physically open up a file in Photoshop to see what it is - kills my productivity at times when I'm dealing with a lot of these.

I note that Adobe DNG Converter refuses to attempt JPEG to DNG.

I don't know enough about the DNG format as to what is allowed inside an DNG. I can see the logic of not converting JPEG to DNG, because DNG is intended for RAW formats and it is somewhat meaningless to convert a JPEG to a RAW format.

Adobe Bridge and Lightroom allow converting of anything (I think) – at least JPGs, to .DNG. I use it for lossless editing of OLD JPG-only camera files (on cameras which didn't even have a RAW output option), via Camera RAW (a la Lightroom Classic 'develop').

I prefer actual Camera RAW + .XMP sidecar files (so edits are NOT dependent on the LrC catalog - which I don't use)... but that's not possible when all I have is JPGs. And it IS true you can have Camera RAW edits embedded inside .JPG's (they don't let you use the sidecar .XMP file), but it seems like not all editors will see those (especially if I send it to somebody who's not a photographer or designer). So I figure if I'm doing it this janky way, I would prefer to use a container that's specifically for Camera RAW - so I'm using JPG's inside a .DNG container. REALLY hope it doesn't come back to bite me in the ass 10, 20 years from now lol... maybe I'll make a topic on this to see how other people handle this...


BTW, if anybody knows how those .DNG's handle the container-ing of non-RAW files I would LOVE to know. Can't seem to find this info via Google. Specifically if the JPG is actually inside that .DNG container still... or if it's converted to which format? And if it is still in there, how to extract properly (besides opening in Photoshop and exporting whatever).