DNG

Pete Gl

Pete Gl

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Errr Pete?
Edit My Images
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I'm a lover of lightroom and have been advised, by somebody I'd trust, to convert all my images to DNG automatically as I import them. However, after doing a bit of research on 'tinternet and forums, the jurys still out.

So I thought I'd ask you guys for your thoughts, but I think I may get as many pro's and ante's on here too.

But it's worth the discussion.

Thanks folks,

Pete
 
I'm pretty sure this has been well covered in older posts. Personally, I don't see the point. If you have the RAW you can do anything but if you go DNG you are committing (regardless of what people say) to Adobe compatible products.
 
isn't the metadata for RAW files kept in a seperate XMP file? whereas in DNG is it all in one, and smaller in Mb terms?
 
One of the main justifications for using DNG seems to be that as it is an open standard future support will be guaranteed.

For me this is a little spurious though as the chances of all the software and knowledge that is currently capable of opening the dedicated camera RAW formats disappearing in the future is highly unlikely.

That said, if all the major camera manufacturers were to adopt a common unified file standard (as they have with jpg for compressed images) for RAW images, I would use it. Who knows, DNG may one day achieve this.

As for DNG being more compact than the associated RAW+XMP sidecar file, I'm not convinced. The whole point of RAW is that it retains all the recorded information in a none-lossy compressed form, surely DNG should be doing the same thing? The metadata, by comparison to the image data, is tiny. Therefore overall storage space should be about the same (ignoring file system overheads).

Edit

Apparently DNG purport to be up to 20% smaller although it would appear that Nikon compresses more than Canon.
 
Meeten said:
isn't the metadata for RAW files kept in a seperate XMP file? whereas in DNG is it all in one, and smaller in Mb terms?
Click to expand...

Yes, and no. If you "embed" your RAW file in the DNG it virtually doubles the size, if you don't, then the DNG is slightly smaller, but, I don't know pro's/con's of "embedding".

Pete
 
DonnaM said:
I'm pretty sure this has been well covered in older posts. Personally, I don't see the point. If you have the RAW you can do anything but if you go DNG you are committing (regardless of what people say) to Adobe compatible products.
Click to expand...

On the contrary. More people have trouble opening their RAWs with their current software that can only be remedied by upgrading, changing software - or converting to DNG.
 
DNGs are about 10 to 20% smaller than RAWs

DNGs contain within them the editing changes created within an editing prog such as LR and PS without the need for an xmp file.

Having DNGs and no xmp files to keep track of makes file management - movement and renaming etc - so much simpler and easier.

Loss of quality converting RAW to DNG? As it is almost impossible to tell the difference between a TIFF and the highest quality jpg produced from it, I think it's pretty pointless trying to decide if a RAW is degraded by converting it to DNG.

I haven't heard of anybody complaining that they cannot open a DNG. Plenty of people have complained that they cannot open a RAW.
 
It has been covered a lot on here, but I am a fan of DNGs for the main reasons of smaller file size and embedded metadata (rather than XMP file).
 
For me personally, I like the sidecar XMP files. If one day I decide I want to totally reset the processing I can just delete it without going into programs. Plus it's reassuring seeing it there and knowing it's doing it's job.
 
MisterE said:
On the contrary. More people have trouble opening their RAWs with their current software that can only be remedied by upgrading, changing software - or converting to DNG.
Click to expand...



That should say:

More people have trouble opening their RAWs with their current ADOBE software that can only be remedied by upgrading, changing software - or converting to DNG.

And how long before Adobe decides to upgrade DNG, but you'll need CS7 of course.


I've NEVER had one single issue opening my Canon raw files with the Canon supplied software, and doubt any Nikon user have problems with Nikon software. Funny how you always need to upgrade or change to Adobe's file format with Adobe software.

As for saving 10% of file size, who cares when 1.5TB external hard drives are under £90
 
ChrisJ_SLH said:
As for DNG being more compact than the associated RAW+XMP sidecar file, I'm not convinced. The whole point of RAW is that it retains all the recorded information in a none-lossy compressed form, surely DNG should be doing the same thing? The metadata, by comparison to the image data, is tiny. Therefore overall storage space should be about the same (ignoring file system overheads).
Click to expand...

Different methods of compression provide very different results when it comes to file sizes.

Just look at regular data compression methods.

ZIP, RAR, GZip, 7Z, etc. They will all compress data down so that it can be extracted back into its original form, but if you take any single file and compress it with various different compression applications, each resultant "compressed" file is going to be of varying size (and you'd be surprised at the size difference in some files).

NEF vs. Whatever Canon RAW files are called vs. DNG is exactly the same.

Better compression and smaller file sizes does NOT mean that they're losing any more or less (or none at all) quality vs. the other formats.
 
also canon software is **** (GUI wise) and adobe are industry standard, whats the issue?

I like dng because I can open straight into someone elses photoshop if I'm about, saves dicking around with camera profiles/codecs/whatever they are
 
also canon software is **** (GUI wise) and adobe are industry standard, whats the issue?

I like dng because I can open straight into someone elses photoshop if I'm about, saves dicking around with camera profiles/codecs/whatever they are
 
DNG's are fine if you are happy using one type of raw converter or being tied to one raw converter or if you belive that ACR is the best raw converter about.

If not (and I personley don't) then DNG will suck for you as it is not catered for as well in none Adobe programs and where it is catered for in third party programs it is never catered as well for as the native raw file.

Me I like freedom of choice so will convert to DNG if need be but keep the Native Raw file.:)
 
As a matter of course, I save off the original raw as an archive, having also created a DNG as part of the ingestion process. This DNG becomes, in effect, the master file which is processed in ACR. A good proportion of the images need nothing more done to them than can be achieved in ACR, so this method works for those images, as I can either save TIF/JPG directly from ACR or use Dr. Brown's 1-2-3 processor to create a whole range of formats and sizes, depending on particular needs.

If work in Photoshop is required, the resultant file is saved as a layered (or sometimes non-layered) TIF and again Dr. Brown's 1-2-3 processor is used to create requirement-specific copies.

Anthony.
 
Thanks for replying everybody, I think I'll stay as I am for the time being until there are more compelling reasons to convert to DNG.

Pete
 
I missed this thread back in June but I'd like to chip in because I am a bit of an evangelist on this issue.

Be clear that if you go and get a raw file ago from 10 years ago it's almost certain you will not be able to open it in any current processing software. There's a good chance that you'll have to go back to a version of Photoshop (or other PP software) that doesn't even work on current operating systems. Do you feel comfortable with that?

The ideas behind DNG are:

1. It is an open standard: Anyone can see the spec and anyone can create software to use it.
2. It is future-proof: It is an incredibly well-specified format and should be able to accommodate most innovations *without breaking backward compatibility*

However, the value of point 1 only really kicks in with widespread adoption by the industry and by users. So the more people who use DNG the more we benefit.

I believe some manufacturers (Hasselblad, Samsung,...?) have built-in support for DNG in their cameras.

Be interested to hear other views

andy
 
I think the issue here is largely one of corporate ownership and trust of large corporations (Adobe) which is ironic because the camera manufacturers are also large corporations and have their own interests at heart with all of the same trust issues.

The ideal would have been for an expert group to set a common standard for RAW files at the outset rather than leave it to the manufacturers. That didn't happen so what we have now is a nightmare scenario where camera manufacturers bring out a new model with software improvements that require upgrades to the RAW processing software in order to handle them. Not ideal at all really.

Adobe have taken matters into their own hands and produced the DNG format and as an act of good faith have made that format open source. Furthermore, as the previous poster stated, they've done their level best to ensure that the standard is fit for future purpose. Even if they did stupidly try to take it back in house, the open source community would support and develop the existing standard. All Adobe would do by taking such action would be to damage their reputation and alienate large numbers of users.

So, on the one hand we have manufacturer specific RAW formats that aren't interchangeable between manufacturers and that may not even be compatible at version level without current software with all of the problems that may be storing up for retro-compatibility, and on the other we have an open standard with full compatibility and as best a guarantee for continued fitness for purpose as can be given without possessing clairvoyance.

Bit of a no-brainer for me really. As long as the IQ isn't diminished I'll take open source over proprietary any time. DNG is the way to go although I'll archive my native RAW files as an insurance policy.
 
MisterE said:
DNGs are about 10 to 20% smaller than RAWs

DNGs contain within them the editing changes created within an editing prog such as LR and PS without the need for an xmp file.

Having DNGs and no xmp files to keep track of makes file management - movement and renaming etc - so much simpler and easier.

Loss of quality converting RAW to DNG? As it is almost impossible to tell the difference between a TIFF and the highest quality jpg produced from it, I think it's pretty pointless trying to decide if a RAW is degraded by converting it to DNG.

I haven't heard of anybody complaining that they cannot open a DNG. Plenty of people have complained that they cannot open a RAW.
Click to expand...

Say's it all really.

DNG :thumbs:
 
I'd keep your camera raw around as well. At present DNG doesn't carry all the data for some cameras (lens correction data etc) and theres still some issues with Nikons encoding of the WB information. It seems there may be changes in the next few years with a possible "standard" raw, whether that will be DNG or something else is open to debate. Theres also talk of DNG2.
 
MisterE said:
DNGs are about 10 to 20% smaller than RAWs
Click to expand...

Not always, My raw (ORF) files are 11.2Mb with a embeded full size preview the same image converted to DNG with a full size preview is 11.9Mb.

DNGs contain within them the editing changes created within an editing prog such as LR and PS without the need for an xmp file.

Having DNGs and no xmp files to keep track of makes file management - movement and renaming etc - so much simpler and easier.
Click to expand...

Not really as most programs (barring the basic OS program) automaticly move the xmp file with the raw file, even dragging a raw file to another folder with a free program as simple as picasa automaticly moves the xmp file with it.

Plus every time you make a change or add a keyword with DNG the whole file has to be updated which takes longer than updating a xmp file and will result in the complete file image being re written if you have a ongoing back up going on as opposed to just changing the seperate xmp file.

Loss of quality converting RAW to DNG? As it is almost impossible to tell the difference between a TIFF and the highest quality jpg produced from it, I think it's pretty pointless trying to decide if a RAW is degraded by converting it to DNG.
Click to expand...

I agree.

I haven't heard of anybody complaining that they cannot open a DNG. Plenty of people have complained that they cannot open a RAW.
Click to expand...

This is only true if you have the latest camera and old software, most people these days update there software nearly as often as there camera's, granted not eveyone.

I'm not anti DNG and use it myself but I also keep my original raws as a back up, just showing how easy it is to make a opposite argument to the DNG one.:)
 
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DonnaM said:
I'm pretty sure this has been well covered in older posts. Personally, I don't see the point. If you have the RAW you can do anything but if you go DNG you are committing (regardless of what people say) to Adobe compatible products.
Click to expand...

Not really, I can open DNG's in Capture One 5, Silkypix Studio Developer Pro4 ( my favourite raw converter), ACdsee Pro 3 as well as my copy of LR3.:)
 
swanseamale47 said:
Theres also talk of DNG2.
Click to expand...

Holy thread resurrection!!!

But it's not a complaint, four months down the line to see if there is any general difference of opinion, I suspect not. But it's interesting to see that there may be a DNG2. Isn't that totally defeating the object of DNG???

Pete
 
Pete Gl said:
Holy thread resurrection!!!

But it's not a complaint, four months down the line to see if there is any general difference of opinion, I suspect not. But it's interesting to see that there may be a DNG2. Isn't that totally defeating the object of DNG???

Pete
Click to expand...

One would hope they will be still compatable. I think the changes are needed to store things like the lens correction data (panasonic cameras I think it was) and the pixel loss with some of the pentaxs. Then theres the Nikon issue, it seems Nikon encrypt some of the data in their raw this is making it more difficult for Adobe to decompile them.

It would seem that the idea of getting all the camera manufacturers to have a "standard" raw is a good thing, it certainly would be for Adobe anyway, but whether it would be better for us is another question.

The problem with any standard is you can't easily change it, that means if any new features come along (say selective focus) then the camera manufacturer may not be able to intoduce it simply because theres not enough leway/code/etc in the standard to fit it in, thats why the makers raw changes from time to time, as they improve stuff they update the raw. If we standarise we'll loose the ability to improve to a certain extent.

My 2c worth (runs for cover)
 
The problem with any standard is you can't easily change it, that means if any new features come along (say selective focus) then the camera manufacturer may not be able to intoduce it simply because theres not enough leway/code/etc in the standard to fit it in, thats why the makers raw changes from time to time, as they improve stuff they update the raw. If we standarise we'll loose the ability to improve to a certain extent.
Click to expand...

The secret of designing a good file format is to allow for extensions. It's a difficult task but IMHO the DNG is a good spec. It's also possible to design in backward compatibility, ie DNG will be a 'special case' of DNG2 and so will continue to work.

I understand why people are resistant to DNG since Adobe have struck out on their own and the manufacturers aren't keen to follow. However, the reluctance to adopt an open standard (DNG or open their own format) is exactly what bothers me: ongoing support is impossible to guarantee. What surprises me is that not many people seem concerned about the possibility of not being able to open their photos in a few years' time...
 
If at some stage in the future support for raw files falls away, it will not happen overnight. I am sure that you will be able to convert your existing raw files to whatever the standard is when and if that happens. In the meantime, I am happy to just shoot in raw on both my D50 and D90 as my PP apps support it and seem likely to do so for the forseeable future.
 
I'm not panicking yet. Theres plenty of support for the main camera makes, I already have several versions of software that will open them if Canon/Nikon went belly up. Personally I'd be more concerned about Adobe shutting shop, I suspect support for dng (not great now really) would soon stop then.
At the end of the day it's another option for archival back-up, should we use it? why not, theres nothing to loose as long as we keep the original raw as well
 
Photoshop will always support the main manufacturers' raw formats. That is, the current version of their formats. But manufacturers change their formats periodically and it's very expensive for adobe to retain backward compatibility. When you're capturing CR5 files don't be surprised if your CR2 files no longer open in photoshop. If you remember to convert to new formats each time there's a change (and that's possible) you'll be fine...
As for Adobe not being around, that's certainly possible which is why dng is an open format, so it can live on. This is an example of where we need to help ourselves: the more demand for dng support, the better for everyone. There's absolutely no reason for manufacturers to stay with proprietary formats.

Or we can ignore it until we find our terabytes of raw file archives are useless.
 
interesting stuff.. and not something i was aware of... or at least not something i'd considered.

There would always be a market though surely for someone to introduce software to 'convert' from one format to another in the future? Similar to what faststone do now?
 
leftcurl said:
iThere would always be a market though surely for someone to introduce software to 'convert' from one format to another in the future? Similar to what faststone do now?
Click to expand...
Or what the Adobe DNG converter does....

If Adobe drop support for old CR2 files, there'll be a big song and dance about it, it will take a couple of years to do and there will be all sorts of free tools available.

Having said that, I don't think they ever will. Some of the file support in Adobe products is pretty archaic as it is and there are an awful lot of CR2 files out there.

I'd concentrate on whether DNG works for you (personally, I like the xmp sidecar files, but can see why you might not...).
 
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