To DNG or not to DNG... (I'd say - don't)

This is just a brief post, inspired by my listening to Inside Aperture podcast while doing my best to stay on the road during a torrential rainfall drive back to Appleton on Sunday evening. Inside Aperture is a great program hosted by the photographer, and Aperture wizard, Derrick Story, for the users of Apple's flagship pro-level photo management software (and Lightroom's main competitor). In the past, I have always had my serious doubts about converting RAW camera files into Adobe's universal and "open" DNG (digital negative) format. I always leave my RAW/NEF photo originals untouched, and never convert them into DNG.

Adobe has put considerable effort into promoting DNG mostly focusing on the fact that propietary RAW files, such as Nikon's NEF's, may one day (in a very distant future) become unreadable, e.g., if Nikon decides to drop its support for specific NEF flavor for older, discontinued camera models. Admittedly, for many pro-photoraphers this is a potential concern. Still the likelihood of this actually happening is small, and it's not any more or less likely than, say, a possible future demise of Adobe and its software.

I always thought that conversion to DNG might potentially irretrievably discard or corrupt some possibly useful information in the conversion process. This week's podcast interview with Joe Schorr, Apple's product manager for Aperture, seems to (indirectly) emphasize that original RAW's are a good thing to have!

As it turns out, in Aperture 2.1, Apple decided to dig a little deeper into previously ignored regions of the original RAW files, and extract lens information to the metadata that Aperture makes available. As it turns out, Apple incorporated into Aperture not just the focal length (usual EXIF information), but the actual, brand and model info. for each lens, which is embedded by many camera manufacturers in the RAW files. While Aperture will read this info. for all new images imported into v. 2.1, Derrick Story asked about the possibilities of adding this info to the older files cataloged in the pre-v.2 Aperture. The application makes it possible to go back to the original RAW files, and automatically extracts this info and adds it to the current metadata.

This is where the DNG factor comes into play: this may be the ultimate argument that one should indeed keep the original RAWs, and not just their converted DNG versions. I believe a future trend for many software developers will be to try to access some of the currently "off-limits" RAW file data. Since I am not sure how much of this data is actually kept, what is discarded, and what might get corrupted in the DNG conversion process, this is just one more argument for keeping Nikon's original NEFs (RAW files) - it just might be a smart thing to do.

Update on Friday, June 20, 2008 at 6:51 by George

Shortly after I posted this, the topic came up again on Flickr, at Aperture user forum (it does return periodically), and I posted two follow-up posts, there (listed as "GJ")