Is there any reason to covert JPEGs or TIFFs to DNG?

[dicksimon]

I am in the process of moving approx 45k images into Peter's DAM system.  These are a mix of NEF, JPEG and a few TIFFS. 

In addition to the question in the Subject, one issue I am facing with the NEFs is that I have created metadata using iView, and am now concerned re how to synch that back to the original NEF files prior to converting in Bridge to DNGs.

Thanks.

Dick Simon

[peterkrogh]

Dick,
You can sync back to TIFF ad JPEGs, so you don't need DNG for that.

If you edit the files in Lightroom or ACR, however, DNG does perform a valuable function that can't be done any other way.

I'd be waiting to implement this however, until things are a bit more fleshed out.
Peter

[ErwinC]

Peter,

"...until things are a bit more fleshed out."
could you elaborte a little on this?

After reading this post http://blogs.adobe.com/jnack/2007/03/converting_jpeg.html on John Nack's Blog I wanted to give it a try, but I would like to make sure there are no issues with converting my TIFFs to DNG files.

I clearly see the advantages: reduced file size (my scanned and edited 16 bit TIFF masterfiles have 600-900 Mb), editing in Lightroom (or ACR 4.1) instead of using multiple layers in PS, full size Jpeg included,....
Also, the settings in the DNG files are recognized by IdImager. Changes in TIFF files that are edited in Lightroom or ACR can't be viewed in IdImager (at least not that I know).

Thanks,

Erwin

PS: sorry for my English. It is not my native language.

[peterkrogh]

Erwin,
I think that was a reference to Lightroom/ACR 4.1 which was very near development when I wrote that.

• As the the sync back for NEF files, if on a Mac, then there is likely no problem - data should transfer fine,.
• If you are on PC, you can only sync back IPTC data, and not XMP stuff like Labels, catalog sets, etc.  I think (IIRC) that IPTC core (Usage Rights, for example) is not supported by the NEF, and will be left behind on Windows.
• If you are on PC, you could write out an XMP file, but if you already have XMP sidecar files with ACR settings, they will be destroyed.
• In this case, you might want to use the keywords as a place to store the important information, sync back, and then re-map the information to a place that suits you.

Peter

[ErwinC]

Peter,

thank you for your answer, but I am afraid I picked up the wrong thread.

What I actually wanted to know is if you know of any issues wenn converting scanned TIFF files to DNG files. For my RAW files I have already adopted your DNG-workflow after reading your book and spending countless hours on this forum.

I am now trying to decide if I should adopt the DNG-workflow to my scanned TIFF-files (35 mm slide) now this is possible since LR 1.1 or ACR 4.1. In my previous post, I already mentioned the post on John Nack's Blog in which he discusses the possibilities.
The reason: wenn I scann my slides, do some editing in PS (grain reduction, capture and creative sharpening, color adjustments,.....) in different layers and save the 16 bit master file as a layerd TIFF, I often end up with master files that are 600-900 MB in size. I know that back up is cheap, but if I would adopt the TIFF to DNG workflow for my scans and could do the majority of the editing in ACR 4.1 (or LR) as metadata editing instead of pixel editing, I would save a huge amount of disk space.
A big plus is that the editing is completely non-destructive. The edits would be as visible in my cataloging software (IdImager) as are the layerd TIFF master files.
I see some clear benefits:
- reduced file size,
- non-destructive metadata editing instead of pixel editing,
- much easier and quicker editing. It is a personal opinion, but I prefer the editing possibilities in ACR 4.1 over the layer approach in PS,
- full-size embedded JPEG preview.
The scan software VueScan even offers the possibility to save the scanned files directly as a DNG file!

But are there any issues I don't know of but should be aware of?

Erwin

[mikewren]

ErwinC,

I too am exploring the risks/benefits of converting scanned TIFF files to DNG.  I've spent more time shooting (and my staff scanning archived 35mm slides and negs) the first half of this year and didn't keep up with DNG development. This weekend was my time to catch up with tech stuff, and I discovered v4.1. 

I was working under the assumption that we would have to wait until our shop migrated to CS3 to take advantage of RAW-like metadata-based edits for TIFF and JPG files.  Not the case!

This morning I will be sitting down with my staff to make sure they are as excited as I am!  I expect converting JPG/TIFF to DNG and just doing the exposure/color adjustments in ACR will be a big time saver for us, as well as being "more safe."  Being able to go back to a scan as it came off the hardware (without having to turn off layers), along with not having the filesize baggage of doing layers, it a huge advantage.

I can already predict one of my staff not liking the inconsistency of non-RAW data being contained in a DNG.    But the benefits seem to be too great.  Always-ready full-sized JPG previews, metadata based edits in ACR... all Good Things.

I too am wondering if Peter has any further thoughts or concerns regarding TIFF/JPG files being put into the DNG container.

[peterkrogh]

Hey guys, sorry for being so brain-dead.  As I look over the original question, I see that my last response was a bit wonky.

Okay.  So there is actually a decent reason to convert TIFF files to DNG, if they are adjusted in Lightroom, and  you want other applicatins to be able to see the Lightroom edits, and wrap up the original data in one file.

So, if you were using Lightrom to edit TIFf scans, for instance, and wanted to manage the collection with iView MediaPro, idImager, or Portfolio, you could save as DNG and it would work.

I would not want to make the DNGs from TIFF files if you are only going to manage in Lightroom.  Think of it as a way to export everything as a bundle.

There *are* some improvements that we could see for the DNG spec that would make this even more attractive.  At the moment, for instance, you convert JPEG data to TIFF format for storage in hte DNG, so it is much bigger than a JPEG original.  It might be possible one day to store the JPEG data inside a DNG file in its original compressed form, so that it retains a small size.  THis kind of use seems pretty attractive, since it would extend the reach and utility of Lightroom with little cost in the form of storage space.

Peter

[mikewren]

While testing the standalone DNG v4.1 converter on various TIFF files, I'm noticing some anomalies:

* Grayscale TIFF scans saved with Mac Photoshop 6 (w/ LZW compression) cannot be converted to DNG (haven't yet tried any other variables, such as color, or w/o LZW)

EDIT: Opening PS6 grayscale TIFF files in CS2, then resaving allows me to convert to DNG with v4.1

* Color TIFF scans saved with PC Photoshop CS2 (w/ LZW) and then converted to DNG, then opened in ACR v3.7 no longer show the color temperature on the slider.  It only shows an integer from -100 to 100 (not a dealbreaker, just an annoyance that's hopefully addressed with CS3).

EDIT: It's a feature, not a flaw, per Peter's post below

I'm sure I'll come across some other weirdness, and will share them here when I do. 

[peterkrogh]

Mike,
Any rendered file will not show color temperature on the slider, by design.  Once the color balance has been baked in by rendering out the file (making TIFF, JPEG, PSD, etc), the temp slider can adjust the file more blue or more yellow.

Open a JPEG in Lightroom or ACR4 and you'll see.

Peter

[ErwinC]

Peter,

I agree that it does not make sense to convert TIFF files to DNG files if one is only working in LR.
At the moment I still doubt whether I should use LR in my RAW workflow or not and when, only to select and edit the RAW files. I find the function to compare 2 images much better in LR than in Bridge CS3. The disadvantage is that I have to import my images in to LR, an extra step in my workflow (but on the other hand, Bridge needs to cache the images as well). Cataloging however happens - and will happen for a while - in IdImager.
The same with my scanned TIFF files. I catalog them in IdImager.
So there is a clear benefit in converting my TIFF scans to DNG files. That leaves my the option to edit them in LR or ACR 4.1, and as stated before, see the editing results in my cataloging software.
Peter, think of it... Rapidfixer perhaps becomes usefull to me

One benefit I forgot to mention is that wenn - in the (near) future - DNG files can include multiple full size JPEG previews, it becomes possible to store multiple versions in one DNG file (B/W version, Sepia version, color version,....). Also for scanned files.

Erwin

[mikewren]

Mike,
Any rendered file will not show color temperature on the slider, by design.  Once the color balance has been baked in by rendering out the file (making TIFF, JPEG, PSD, etc), the temp slider can adjust the file more blue or more yellow.

Open a JPEG in Lightroom or ACR4 and you'll see.

Peter

This makes sense, actually, thanks for clarifying. Lightroom is not yet part of our workflow, hopefully by the end of the year.

Another interesting piece of info from Thomas Knoll concerning images scanned with Nikon hardware that may be useful for folks: The resulting TIFF file is identical to the Nikon "RAW" NEF file:  Here is the discussion. 

Thomas Knoll  - 7:57am Aug 9, 07 PST (#7 of        

Nikon's "scanner NEF" files contain EXACTLY the same image data is their TIFF files, just packaged differently in a way that is incompatible with normal TIFF readers such as Lightroom.

We will probably add support for these files in some future version, however this will only be so users don't have to convert these files to normal TIFF files using Nikon software. This future support would have absolutely ZERO quality advantage over just using TIFF in the first place.

In the meantime, just use TIFF with Nikon scanner software. Using "scanner NEF" is a waste of time, and is completely pointless.

Wish I knew this a few months ago.  No damage done, just a lot of redundant wasted space on my production array to clean up now.

[mikewren]

The old scanned TIFF files I'm testing were actually saved with Mac Photoshop 6, not 7 (edited in my above post). 

As we all know, not all TIFF files are created equal, however it's important to note that DNG converter v4.1 will choke on certain TIFF files (giving a potentially confusing error message complaining that the input file(s) are not RAW).  I haven't seen this issue discussed anywhere, and think it's a good caveat to be aware of when approaching conversion of TIFF to DNG.

If anyone stumbles across any relevant threads over on the Adobe Forums or elsewhere, please pass them along.


Mike

[Valeria Lages]

        Hello,

       Actually I use LR in my entire workflow, editing DNG converted from the original RAW files. However, before start shooting RAW,  I've  stored miles of TIFF (from camera and from 35mm slide scanner)  and JPEG files (original camera). Now I'm thinking about converting these TIFF and JPEG files to DNG in order to edit them in LR. Looking for some light in this forum, I found any, but the answers were posted two year ago and there were some expectations about new improvements on DNG .

       Is there any news about that?  Which are now the real advantages of converting my TIFF and JPEG files to DNG in order to edit them in LR?  Should I keep the  original TIFF and JPEG stored also or only the converted DNG?

       If there is no reason to convert JPEG to DNG, would it be better to convert it to TIFF to edit it in LR?

       Thanks,

       Valeria

[peterkrogh]

Valeria,
Not very much new.

1. If you have 1-layer TIFFs or JPEG files, the best reason to convert them to DNG for archiving is that the validation hash in the DNG makes them automatically verifiable. 

2. If you can take the hit for file size requirements, there is one additional advantage for JPEGs. Any resaving of the JPEG is a destructive edit.  Saving as DNG keeps you from ever doing that. If you want to make a parametric edit (edit in Photoshop), you are required to make a new file.

3. TIFFs don't have the issue of destructive edits, but they also don't get any bigger (or at least not much bigger) when converted to DNG.  Of course this is only for single layer TIFFs.

4. The advantage for either is that the parametric edits are more likely to be shown with a DNG file than with a TIFF or JPEG, which may inadvertently be displayed with the edits disregarded.

5. Saving as a DNG does make these files less universal than the very well-supported TIFF and JPEG. As an archive format, however, you're not immediately as concerned with universal support.  Files that get sent out are likely to be derivatives.

Peter

[Valeria Lages]

     Peter,

      Develop TIFF and JPEG files in LR is exactly the same then developing DNG?

     Or DNG has any self advantage to be developed in LR? If there is not, I can convert both TIFF and JPEG to DNG only when I export files, after having developed them?

     I mean, while I don't save JPEG (that occurs during the exportation) there is no destruction, right? 

     Valeria