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Daddy, where do DNG files come from?
May 10, 2008
Sometimes our children approach us with questions that are difficult to answer. My son, who turns 21 this month, asked this question a few days ago. I sent him to his mom.
As I mentioned in
my last blog, Adobe’s DNG file format is really good thing, but not many use it. It eliminates one of the most troublesome problems with image portability and archiving, that being the DXF files that are created by Adobe Bridge and Photoshop, and which are often (usually) left behind by people when they copy photos from one location to another. DNG files can contain all of the camera data (EXIF) and the IPTC data (keywords, copyright, etc.) without making those ridiculous sidecar files.
So, now that my son is out of earshot, let’s talk about the birds and the bees and the DNGs. DNG files are made in the camera on only a few cameras. One of them is Hasselblad, the high-end digital medium-format camera from Sweden. Three others are listed by Adobe on their DNG information pages, and I can find no others. If you were to take images from one of these cameras which produce DNG in the camera, the files are already in that format, and nothing more need be done.
The Adobe DNG Converter program is proivided with Creative Suite. It can also be downloaded from Adobe's web site.
The second way to make DNG files is to use Adobe’s free DNG Converter program, which will convert one or more images from their current format to DNG. Photographers who work with raw images, and most do, can convert any photographs to DNG complete with embedded information. This requires an extra step, and creates a duplicate of each image, doubling the file space taken to store photos. It also creates a dilemma for photographers, prepress people and archivists. Do you keep the original as an emergency back-up? So far, I have been keeping both the DNG and the original, but that is truly wasteful of drive space.
In Adobe Bridge there is a function called Get Photos from Camera… which can also convert to DNG simultaneously.
The third method is to import photos from the camera and convert to DNG on the fly. On my last few batches of photos, I have taken the bold step of importing the images from the Compact Flash card directly to DNG, and letting the original raw files go off to digital heaven. To do that, I have been using the
Get photos from Camera… function in Adobe Bridge, which reads the images from cards and cameras and transfers them to the local computer. A part of that tool is a Convert to DNG function, which will convert the images from their original camera Raw format into DNG on the fly.
The resulting files are DNG when they arrive. After that step, I embed copyright information, keywords and captions, and the information is embedded in the files. This ensures that when I send a photo to production, to an archive or a stock photo agency, the data that I intend to send will be there too. DNG files act like camera Raw files in every respect, so I don’t have to change my methods for opening, adjusting and correcting my images.
I’m sold on the DNG file format, but I am going slowly into this transition, being careful to be sure that I am not creating any new trouble when I make my files, and move them around. One must be discreet about sensitive topics like this.
Posted by Brian Lawler on May 10, 2008 | Comments (0)
