This was planned as a fairly short blog post (for me), but it didn’t work out that way. It describes an experiment that I thought would work, and it does. Before we get started we need to iron out a few terms. A ‘RAW’ file in the world of digital photography is essentially the raw data from the camera sensor. In order to be able to see that raw file as an image, it needs to be run through some software called a raw converter. Don’t worry, we’re not going to be throwing around terms like linear demosaicing here – suffice it to say that the raw converter takes the original image data and massages it into an RGB image that looks like a photograph. Now, one of the challenges for people that make raw converter software (ACDSee, Adobe Camera Raw/ Lightroom, Apple Aperture, Bibble, Capture One from Phase One, etc) is that camera companies regularly put out new camera models and these same companies seem to take great delight in creating new, proprietary raw formats for each camera they release. In response, the software companies need to regularly release updates to their software that include these new camera profiles. Going from Lightroom 3.x to Lightroom 4.x for example is a software upgrade and includes a number of new features. Going from Lightroom 4.3 to 4.4 includes some bug fixes and updates, but it also includes profiles for two dozen new cameras.
Now, as a photographer one can run into a challenge of having a new camera but not having the most up-to-date software to work with the images that camera generates. That was the problem faced by our friend… we’ll call him ‘Mike’. Mike has a new Nikon D7100 camera. Mike has Lightroom 3.6 and isn’t really interested in upgrading to Lightroom 4.4 at the moment (the latest release and the one capable of recognizing the D7100 profiles). Mike can use Nikon Capture NX 2 to convert his raw files, but in doing so he loses the DAM (digital asset management) support of Lightroom that he’s used to. Mike can convert his raw files into .tif files in NX and then import those images into Lightroom, but he’s no longer dealing with raw files. Enter .dng files.
DNG (Digital Negative) is an open-source RAW format made available by Adobe. Because it’s open-source it’s not proprietary and anyone can use it. A couple of camera manufacturers allow the user to shoot natively to .dng, but when importing to Lightroom (for example) one can convert any (supported) raw images to .dng files. That doesn’t help Mike, however, because Lightroom 3.6 won’t recognize the raw files generated by the D7100 camera. Even if he opens the LR 3.6 import dialog and selects ‘Copy as DNG’, that won’t work. There is, however, a solution. It’s something I’ve often wondered about, but never tried, until today. I have both LR 3.6 and LR 4.4 on my computer, so I knew I’d be able to see the D7100 images. I asked Mike to send me a junk image, which he did: this one, actually. It’s a picture of his ceiling. So what.
Now, Adobe makes two raw converters: Adobe Camera Raw (for Photoshop) and Adobe Photoshop Lightroom. Equivalent versions use exactly the same processing engine. When a new version of ACR is created, Adobe also generates a new version of a free program called ‘Adobe DNG Converter‘. DNG Converter, as its name implies, is a simple program that does just that: it takes raw files and converts them to .dng files. It can also take .dng files and extract the embedded raw files from them.
The software works on a folder basis, so the first step was to point it to the folder containing the file he sent me. I had no need to change the save location, so I left that alone. Under preferences there are options for Camera Raw compatibility, and this one I questioned, because LR 3.6 is equivalent to ACR 6.6. In the end I tried both leaving it as it was at 7.1 and converting back to ver. 6.6. It didn’t matter. One can also embed the original raw file into the .dng, which I didn’t bother to do. Finally, press Convert and the software will take all of the raw files in that folder (and subfolders, if selected), and create .dng files from them. Voilà! You’re done.
One final thing to mention, when you import images into Lightroom, the default File Sort is by File Name. However, in this case what will happen is that you will have File1.dng, File1.raw, File2.dng, File2.raw, File3.dng, etc. Like this:
Rather than going through and unchecking all of the raw files (that Lightroom can’t read anyway), simply Uncheck All, then change the Sort to File Type. Now, select the first .dng image, Shift-select the last one, and check one of those to select them all. Lightroom will now only import the .dng files. Whether to embed the raw files into the .dng files, whether or not to keep the original raw files, those choices I leave to you. Using Adobe DNG Converter will not give you the processing options available in Lightroom 4.x for example, but it will allow you to open images in newer formats using legacy software.
Now go out and make some photographs!
P.S. II, the sequel: This is what I sent back to Mike. I didn’t tell him how I did it, but if he’s read this, he now knows! 😉