For those who don't know, RAW is a file format where your camera takes all the information that the sensor captures and writes it to the flash card without turning it into an image. This allows you to have much more control over turning that data into an pretty picture, in your computer when you get home, instead of having you're camera just turn it into a jpeg. I shoot RAW almost exclusively. As my 'look' is largely created in post processing, having the extra information that a raw file contains (12 or 14 bits per channel instead of 8) gives me much more headroom for manipulation. It's also saved my ass more than a few times due to mistakes in exposure and white balance.
Canon and Nikon cameras save raw files in their proprietary .CR2 and .NEF formats, respectfully. While Lightroom and Photoshop and Aperture and all the rest of the aftermarket raw converters can currently open these formats perfectly well (sometimes you've got to wait a month or so for them to add support for new cameras). Will that be true in 10 years? If Canon goes and changes their format, is Adobe going to continue to support RAW files from the original Digital Rebel from 2004? And wouldn't it be better to have them in some publically documented format that a number of different companies support?
Well, DNG is an open raw file format that Adobe has come up with. DNG, as in Digital NeGative. A handful of cameras use it as their default RAW format, such as the sexy Leica M8.
Some people think Adobe's DNG format is the answer. There are free converters available that will turn your .CR2 or .NEF files into .DNG files. With a few practical upshots that I've found. For one, Lightroom no longer has to keep metadata in additional .xmp 'sidecar' files. So my hard drive has less crap all over the place. One file per image instead of two. And secondly, Adobe has included lossless compression of the raw data so it takes up less space on your hard drive without losing any data.
Anyway, I took the plunge this week and had Lightroom convert all 26,000 or so CR2 files in to the DNG format. In the process I gained back 100GB of drive space, I assume, due to the lossless compression.
Some people claim that upon conversion, you're losing additional undocumented metadata that the camera added to the images. I'd really like to know what kind of data they're talking about because I haven't noticed anything missing. As long as it keeps the date, iso, exposure settings, and copyright, I'm not sure what else I could really need. Either way it's too late for me, I've jumped in with both feet.
So, if you've got any thoughts, comment, questions, or rants on the subject, we're all ears.
Feel free to tell me that I'm crazy and a fool if you like. I'm used to it. ;-)