Announcement

Collapse
No announcement yet.

How exactly does Lightroom CC merge DNG files?

Collapse

Related Topics

Collapse

  • pavel123
    RAW to JPG in Adobe Lightroom 1.0
    by pavel123
    I was wondering if there is an easy to save RAW files processed in Adobe Lightroom and then exported to Photoshop as JPEG.

    I normally adjust RAW files in Lightroom and then use an option "Export to Photoshop with Lightroom adjustments". The file is then exported to Photoshop...
    05-14-2009, 08:23 PM
  • Nasturtium
    preserving LR keywords...PS image Processor
    by Nasturtium
    I've been running large batches of very high ISO RAW files through the Noiseware...which saves a TIFF file...this seems to strip off the EXIF data :-(

    I'd like to keep keywords written to the RAW file in Lightroom

    Can a keyword be preserved in a TIFF file?
    06-11-2014, 11:30 AM
  • ir0nma1den
    Using Lightroom instead of the RAW converter
    by ir0nma1den
    I'm trying to absorb as much as possible off of you people so I can get a solid workflow going.

    Currently I use Lightroom(3) as a photomanagment program where I do a ghetto color correction job, adjust exposure, play with curves, and then I edit in photoshop as a smart object.
    ...
    06-29-2012, 11:51 AM
  • Robbie Dahl
    Converting RAW to DNG
    by Robbie Dahl
    I would like some advice on converting RAW to DNG. I have read on line that it is a good practice to convert all my RAW images to DNG after uploading them. I am using Adobe Lightroom 2.2. When I use "Convert to Linear Image", my files double in size. Should I be using "Preserve RAW Image"...
    01-21-2009, 12:41 PM
  • Caravaggio
    how do you open MOS files?
    by Caravaggio
    Does anyone know how to open MOS files not using Capture One? MOS files won't open in CC camera raw for me. Under get info it says that it is a Leaf RAW image.
    I had a free trial to Capture One, but it expired and I am not eager to purchase it.
    Thanks for your help.
    12-29-2013, 09:50 AM
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • How exactly does Lightroom CC merge DNG files?

    Andrew Rodney corrected me in another thread for my faux pas in my recent Lightroom CC RetouchPRO LIVE show.

    I said in the show that Lightroom CC generates DNG files from HDR Merge and Panorama Merge and that was fabulous because you basically had this big honking Raw file to work with.

    Andrew pointed out that I was almost correct in that it does generate DNG files but they were not precisely the same data as multiple Raw files embedded in a wrapper. It was something something linear something.

    So what is it precisely you get in a merged DNG from Lightroom? Is it some of the Raw data (and which part) or is it pixels like in a PSD, or something else?

    Feel free to geek out on me, as I really want to know precisely what is in that merged DNG and how it differs from the original Raw data.

  • klev
    replied
    Re: How exactly does Lightroom CC merge DNG files?

    Originally posted by Flashtones View Post
    That would be good of you. I'm just looking at it now, on your recommendation. Pretty rich feature set. I'll certainly give it a spin.
    They have some people who are obviously very very good at writing clean C code. At least that seems to be the case browsing through their github page. I am planning to look for something small to patch first. These projects don't typically allow new contributors to implement anything cool due to the number of things that could be broken in the process.

    Originally posted by Doug Nelson View Post
    I got a response from Eric Chan, Principle Scientist for Adobe and Lightroom. No real new info, but I thought I'd share:
    Those details are actually in line with what I would have expected. You start off with some form of single channel pixel sequencing, which is specific to the camera model in question. It's always some well defined sequence of the form RGBG in the form of a 2 dimensional array. They have to take that and produce something with 3 channels in a suitable working space to make further adjustments.

    I'm not going to claim the stuff is simple. I've been working on a small amount of it myself during free time. It's extremely tedious, and the learning curve is somewhat drastic for lower level operations. I'm less interested in raw processing than I am in improving results on already processed data due to the shear number of images that are encountered in that form via images shot in jpeg form, scans, etc.

    Leave a comment:


  • Doug Nelson
    replied
    Re: How exactly does Lightroom CC merge DNG files?

    I got a response from Eric Chan, Principle Scientist for Adobe and Lightroom. No real new info, but I thought I'd share:

    Hi Doug,

    A bit of background (apologies if you're already familiar with this part): Raw files are usually in so-called "mosaic" form. They need to be interpolated (demosaiced) before they are useful for photographic editing.

    And then comes all the fun stuff you're familiar with: white balance, exposure, contrast, and all the normal edits one can do with a raw file.

    When we merge raw files into a HDR, or panorama, or even a HDR panorama, we need to first interpolate (demosaic) the raw files. Then we do the merge of the interpolated RGB color data. And then we store the results into a DNG file.

    The crucial part of this is that your normal Develop adjustments, such as white balance, exposure, contrast, etc. -- have NOT yet been applied. This means that you have full freedom to make these adjustments to the resulting merged DNG file, just like you would with a regular raw file. This is a very important workflow and quality benefit, over previous merge/stitching solutions.

    Please let me know if I can help clarify any of this. (I have not yet registered for the forums, but you're welcome to re-post any of the above publicly in the forums, if you wish.)

    Cheers,
    Eric

    Leave a comment:


  • Doug Nelson
    replied
    Re: How exactly does Lightroom CC merge DNG files?

    Mark Fitzgerald forwarded me this link of an interview with Adobe engineer Eric Chan. There are two parts, be sure to click through to part 2. It's the most in-depth information I've seen so far, but I'm still only about 90% clear.

    tl;dr: The DNG is rendered pixels, not raw data, but in 16bit floating point so there is more information than in a standard TIF.

    Leave a comment:


  • Flashtones
    replied
    Re: How exactly does Lightroom CC merge DNG files?

    Originally posted by klev View Post
    I've actually been looking at darktable. If I get the time I might even try to contribute to it. It's still a bit unstable on OSX.
    That would be good of you. I'm just looking at it now, on your recommendation. Pretty rich feature set. I'll certainly give it a spin.

    Leave a comment:


  • klev
    replied
    Re: How exactly does Lightroom CC merge DNG files?

    Originally posted by Flashtones View Post
    Listen, don't sweat it. I'm just frustrated with Adobe's raw processing engine and looking for a more elegant workflow that might bridge or transcend other processors. Thought this linear DNG might be it, but it's not. I'll figure something else out.
    I've actually been looking at darktable. If I get the time I might even try to contribute to it. It's still a bit unstable on OSX.

    Leave a comment:


  • Flashtones
    replied
    Re: How exactly does Lightroom CC merge DNG files?

    Originally posted by andrewrodney View Post
    It's not at all arcane! It's linear scene referred data without WB applied. It's not as raw as the original DNG's or the proprietary raws prior to the merge. It's partially processed. DNG doesn't necessarily equal raw! Neither does TIFF. There's nothing arcane about it and in fact, now that you know the differences using HDR/Pano merge upon the original data, it should be even less arcane if you actually think about it.
    I get you. Saying it was a good question for Chris Cox threw me, but I guess you thought I was asking something else.

    TIFF is again just a container for rendered data. Saying you're sticking with TIFF means you're not doing any HDR/Pano merges which is fine with me. The linear scene referred data could just as easily be saved in the TIFF container but it's stored in the DNG container, so what? Makes zero difference.
    I don't expect you or anyone else to care what I do. I simply meant that once I understood a linear DNG to be of limited utility outside of the Adobe ecosystem we didn't have to pursue the details within it ad nauseum.

    Listen, don't sweat it. I'm just frustrated with Adobe's raw processing engine and looking for a more elegant workflow that might bridge or transcend other processors. Thought this linear DNG might be it, but it's not. I'll figure something else out.

    Leave a comment:


  • andrewrodney
    replied
    Re: How exactly does Lightroom CC merge DNG files?

    Originally posted by Flashtones View Post
    Andy, if what's inside of it is so arcane that even the likes of you and Schewe, etc, barely know what it is, I'm thinking I don't need to know either.
    It's not at all arcane! It's linear scene referred data without WB applied. It's not as raw as the original DNG's or the proprietary raws prior to the merge. It's partially processed. DNG doesn't necessarily equal raw! Neither does TIFF. There's nothing arcane about it and in fact, now that you know the differences using HDR/Pano merge upon the original data, it should be even less arcane if you actually think about it.
    I'll be sticking with TIFs.
    TIFF is again just a container for rendered data. Saying you're sticking with TIFF means you're not doing any HDR/Pano merges which is fine with me. The linear scene referred data could just as easily be saved in the TIFF container but it's stored in the DNG container, so what? Makes zero difference.

    Leave a comment:


  • Flashtones
    replied
    Re: How exactly does Lightroom CC merge DNG files?

    Andy, if what's inside of it is so arcane that even the likes of you and Schewe, etc, barely know what it is, I'm thinking I don't need to know either.

    I'm all about getting the work done. If there's indeterminate/minimal benefit to the internals, and negative benefit to the packaging, I'm over it. I'll be sticking with TIFs.

    I appreciate the dialog, though. Thanks.

    Leave a comment:


  • andrewrodney
    replied
    Re: How exactly does Lightroom CC merge DNG files?

    Again, what do you mean by High bit TIFF. The Linear DNG data is also high bit. It's scene referred not output referred, there's no white balance applied AFAIK (that's the bit about being more raw). You could put exactly the same kind of data in a TIFF. TIFF and DNG are containers, what's inside is what you want to know about.

    Leave a comment:


  • Flashtones
    replied
    Re: How exactly does Lightroom CC merge DNG files?

    I don't understand Linearized DNG, and I guess I'm wondering if I need to or want to. I just hear it's kinda closer to raw than a baked-in file, but not all the way raw. And I'm wondering how useful this nuanced difference between a Lin DNG and high bit TIF is.

    As an example in a workflow, I was excited to see that Helicon Focus can take raw images (in my case a focus stack) and render them as a merged DNG. I was excited by this, thinking I could then take this kinda raw merged DNG into C1 for processing, assuming C1 would surely work on the "wonderful" open source raw format, but it does not. To do what I want instead requires outputting a high bit TIF to work on in C1.

    That C1 can process a TIF is an advantage to the TIF. What I'm wondering is what I'm losing by using a TIF vs a DNG. What can the Lin DNG do (be it C1 or elsewhere) that the high bit TIF can't?

    If the answer is "nothing" I need not be concerned with that format at all as it would yield only negatives and no positives.

    Leave a comment:


  • andrewrodney
    replied
    Re: How exactly does Lightroom CC merge DNG files?

    I don't know how to get linearized from raw into a TIFF. I'm sure it can be done. Getting linearized DNG is just a setting. I don't think it matters. It's the data that is important, not the container. TIFF and DNG are cousins. This would be a good question for Chris Cox or some one inside Adobe.

    Leave a comment:


  • Flashtones
    replied
    Re: How exactly does Lightroom CC merge DNG files?

    Andrew, in a practical sense, is there an advantage to a linearized DNG over a 16bit TIF?

    The TIF is more flexible, can be used in/by more programs, so what advantage might the Lin DNG confer to make it worthwhile?

    Leave a comment:


  • andrewrodney
    replied
    Re: How exactly does Lightroom CC merge DNG files?

    That function is to extract the original proprietary raw file IF you set the DNG to embed it when converting initially.

    Leave a comment:


  • Doug Nelson
    replied
    Re: How exactly does Lightroom CC merge DNG files?

    I tried the following experiment and it failed. But it was still interesting and might be fruitful with some option changes in Lightroom.

    The Adobe DNG Converter has an extraction function. I have 2 DNG files, one of which I explicitly told to embed the original Raw data.

    I ran the extractor on both files and came back "no files were extracted".

    More fiddling required. Feel free to experiment on your own and report back any positive results.

    Leave a comment:

Working...
X