Lightroom - Exporting ARW files with adjustments

[TFD]

I run Lightroom 3 (and CS5) on both my laptop and my desktop. My workflow is to import my .arw files from my camera to the laptop, make adjustments in the Lightroom Develop module, and then, using Lightroom, export batches of developed files to a memory card - I then transfer that memory card to my desktop (which is the permanent home for my photos) and import the files into Lightroom on the desktop. This is a new process for me, and I found that the Lightroom adjustments were not transfering along with the .arw files.

After a couple of hours with a (very nice) Adobe technician, I found that the only way to get my Lightroom adjustments to transfer with my photos is to convert my .arw files to .dng format during the export to the memory card. The .dng files and adjustments then import properly from the memory card into my desktop. Adobe said they will look into the reason the transfer doesn't work properly with .arw files and get back to me.

Does anyone else have this issue? Is there any reason to prefer .arw files to .dng files, or should I just go with the flow here and use .dng from now on.

Thanks!

[Winston]

You can "Export as Catalog". Be sure to turn on "Export negative files".
Then import the exported catalog into the catalog on your desktop.

Another option is to "Save metadata to file" on your laptop. This will create sidecar files, one for each raw file. Then import them into your desktop's catalog. This is the method I would use.

[01af]

When making adjustments to raw files that are no DNG files then the adjustments will get stored either in XMP side-car files or in the central Lightroom database. Check your Lightroom preference settings to find out which option is selected! In order to be able to transfer the images files including the adjustments to another computer, you must save the adjustments in XMP files, not in the database. So each raw image file that has adjustments consists of two files: the ARW file containing the raw image data and the XMP file containing the adjustments.

Moreover, when Lightroom cannot write to the medium where the images are (the memory card in your case)—when some software or hardware write protection mechanism is engaged, for instance—then it also will store the adjustments in its central database instead.

So—make sure adjustments get stored in XMP side-car files rather than in the central database, make sure your memory card is not write-protected, and make sure the XMP files actually get transferred during export! If for some reason the XMP files holding the adjustments are there on the laptop's local disk but Lightroom fails to transfer them to your memory card in the export process then you can just as well transfer them by hand—simply copy the XMP files to the memory card or to an USB stick, then paste them into the folder on your desktop machine where the ARW image files reside. Lightroom and Camera Raw will recognize the association between an image file and the associated XMP file simply by file name whenever the XMP file is located in the same folder as the image file and has the same file name (for example, the side-car file DSC01234.XMP belongs to the image file DSC01234.ARW in the same folder).

When renaming image files, make sure the associated XMP files (if any) also get renamed accordingly! Lightroom's and Bridge's batch rename feature takes care of that automatically. Also, when converting ARW files into DNG format then the contents of the associated XMP files (if any) will get included in the resulting DNG files automatically.

Generally, you don't need to convert proprietary raw files (such as Sony ARW files) into DNG format just in order to be able to transfer them including their adjustments from one machine to another. Just make sure you always know where your XMP files are! Of course, in DNG format things are slightly easier because it doesn't need XMP files—and thus they cannot get lost inadvertently—but it's not required.

[Winston]

When making adjustments to raw files that are no DNG files then the adjustments will get stored either in XMP side-car files or in the central Lightroom database. Check your Lightroom preference settings to find out which option is selected! In order to be able to transfer the images files including the adjustments to another computer, you must save the adjustments in XMP files, not in the database. So each raw image file that has adjustments consists of two files: the ARW file containing the raw image data and the XMP file containing the adjustments.

Writing to XMP is optional. Writing data to the database is not.

[TFD]

First of all, thank you so much for these thoughtful responses! Very much appreciated.

Second, my research suggests that I would be at no disadvantage, and might possibly be at an advantage in some cases, if I convert to DNG files on import. That would seem to be the easiest way to deal with this issue, too. Any thoughts on format preferences?

Again, thank you!

[01af]

... my research suggests that I would be at no disadvantage, and might possibly be at an advantage in some cases, if I convert to DNG files on import. That would seem to be the easiest way to deal with this issue, too. Any thoughts on format preferences?

Converting from ARW to DNG has many advantages and one disadvantage—you'll lose the ability to use Sony Image Data Converter (IDC for short) as your raw converter. IDC can handle ARW files only, no DNG files ... and it's a poor converter anyway so most people prefer other raw converters, like Adobe Camera Raw, Adobe Photoshop Lightroom, Apple Aperture, Bibble, Capture One Phase One, Ichikawa Silkypix, Raw Developer, Raw Therapee, etc. Still, IDC has one special property—it's the only raw converter that can handle Sony's DRO+ settings.

By the way, Adobe DNG Converter usually applies lossless compression to the image files so after DNG conversion they're smaller than before—except when Sony's raw format compression (ARW cRaw) was used. Uncompressed ARW Raw file get shrinked to approx. 50 - 55 % of their original size during DNG conversion. ARW cRaw files, however, will increase in size when converted to DNG (still smaller than ARW Raw files but larger than DNG files created from ARW cRaw files). So when shooting ARW Raw rather than ARW cRaw then you'll use more card space at shooting time but you'll save disk space in your archive after DNG conversion.

[TFD]

Really helpful . . . Thank You!!