Raw processing attracts a lot of attention on photo forums, unfortunately not all of it well-informed. As I’m writing about it for a forthcoming issue of the UK magazine N-Photo, where I’ve taken over the Nikopedia section for a year, I thought I’d look and see what photographers tend to think and say about it. To be honest, the most impressive thing was the amount of bad temper and argument displayed. Perhaps it’s a macho thing, the idea that it’s manly to know about software, algorithms and the math behind it, rather as it used to be manly to be able to fix a car engine.
Well, the math is complicated, and there’s no need for pride to be involved unless you’re a software engineer by profession. But the principles are not complicated. At its very simplest, a digital camera, and especially a DSLR, captures much more information about tone and colour than can be displayed in a photograph or seen by the eye. The image as captured has to be processed somewhere to turn it into the JPEG or TIFF that is the usual end-product. You can let the camera’s processor do it by choosing NOT to save the Raw file, and you’ll have a JPEG or TIFF as the result. Or you can choose to save the original data in its raw, unprocessed form (hence the name Raw) and do that processing for yourself later on a computer with processing software like Adobe’s in Photoshop or Lightroom, or DxO Optics Pro, or the camera manufacturer’s own software, or any of dozens of raw processing engines, as they’re called. Here are the main reasons for choosing to do this:-
1. The raw file keeps the full image quality
2. You control what image data to use for the final JPEG or TIFF from the surplus available
3. Better processing is available with software that can be run on a computer than in-camera, especially demosaicing
4. You can often recover exposure ‘loss’ in highlights and shadows
5. The software engineering behind raw processing continues to improve, and you’ll be able to re-visit images saved as Raw
6. It’s impossible to overwrite a Raw file, so it’s safer archivally
The arguments against revolve around time and space. Raw files take up more space than JPEGs, take longer for the camera to save as you shoot, and take time to process on the computer.
Meanwhile, for a clear and comprehensive description of what you can do in processing a raw file, the following link to Adobe is hard to beat:-