Baking Copies of your Work

by James Duncan Davidson

Last week, over on the Inside Aperture blog, Micah Walter mused on what would happen if his RAW workflow tool went away. What would happen to the metadata and the image adjustments? I have to admit, it's a thought that I've wrestled with quite a bit myself having used both Aperture and Lightroom and moved between the two. It's a different set of issues than we had with back in the good (*cough*) old days of film, but it's just as important.

Luckily, thanks to XMP and the like, transporting metadata such as titles, copyrights, and descriptions between tools is no longer rocket science. But, what can and does get lost in a move between tools is all the work you put into adjusting images. Given that each RAW processor works differently, and supports a different set of image adjustments, it's probably not going to be possible to come up with a standard for preserving the processing instructions that go along with each image. I could be wrong (and I hope I am), but I think it's a long shot.

This problem, however, doesn't just manifest itself between tools. It also manifests itself between versions of a tool. As RAW converters are improved, the images you made adjustments too last year might not look the same after upgrading Lightroom. I'm aware that Aperture provides a way to use previous converters, but how far back will that support go?

So what is one to do if they perfectly tweak an image to their liking and want to keep it for posterity? At this point, the only sane thing to do is to bake—my pet term for export—a TIFF or PSD file, preferably in 16-bit format. This will ensure that you can keep your currently processed image no matter what happens in the future with your choice of tools. Of course, now you have another file to manage. And that becomes another problem.

Maybe DNG could help us out with this. It's already possible to include multiple representations of RAW data in a DNG file. Maybe if the keepers of the DNG spec were to add an ability to include "snapshots" in TIFF or PSD format into a DNG, we could package our processed versions of a photograph together with its RAW data in such a way that could survive the test of time in one handy package. That way, even if you move from Lightroom to SuperDeluxRAWTool in the future, you can always access how your photos looked when you made your edits in late 2007.


2007-12-11 20:53:45
Damn Straight. I keep telling people that RAW is not an archival format, since the bits that are there require interpretation. Basic tiffs (and jpeg if the quality is good enough) are the formats that will most likely be readable and representable in the same way in the far off future. (though, colorspaces will probably throw a wrinkle in that...)
Bruce McL
2007-12-11 22:29:49
As Eric said, a JPEG file, with an attached color profile, is more definitive than a RAW file. But it's not necessarily more accurate. What color and tonality information is a JPEG file guessing at that is not recorded in a RAW file? How can this information be recorded better at exposure time with a digital camera?