Enthusiastic about iPhoto 5‘s ability to handle RAW images from digital cameras, Amy shot a short roll in RAW, only to find that iPhoto 5 refused to import them. Eh? I probably should have known this, but it turns out that RAW (known as NEF in many Nikon cameras) is not a file format as such, but a representation of the actual bits coming directly off the image sensor, with no in-camera processing whatsoever. Because image sensors are different from camera to camera, so is the layout of the raw data. So not only do RAW formats differ from one manufacturer to another, but even from camera to camera by the same manufacturer. In fact, the RAW “format” sometimes changes within a single product line! iPhoto’s list of supported cameras (lower right of that page) shows that iPhoto supports the PowerShot G5, but not the PowerShot G2, which we have.
The idea of RAW is that the photographer gets a “digital negative” — the most possible data available for post-processing and archival purposes. The downside is that image manipulation applications need to know the specifics of the data layout on the CCD to be able to do anything meaningful with the images. To overcome this compatibility problem, some cameras do perform a minimal amount of processing on the image before storage (e.g. “RAW+JPEG”).
So why don’t cameras simply support one of the many uncompressed image formats available — say, TGA or BMP or uncompressed TIFF? No data loss or compression would be necessary, and the application-level compatibility issues would go away.
Photoshop supports RAW for a wide range of cameras, and there’s the dcraw.c library for Linux, which supports some 87 cameras — so the code is out there and we can expect to see better iPhoto RAW support in the future (hopefully there’s a RAW plugin architecture at work here). But it bugs me that application vendors should even have to worry about this kind of thing. I’m sure insiders can come up with all kinds of historical and technical explanations for how we got to this point, but it’s a classic example of an industry working at cross-purposes to itself.