Using 16-bit wide gamut color spaces for RAW file conversion

2010-10-07 • SEND FEEDBACK |
Related: color space and gamut, Scott M

Subscriber Scott M writes:

I wanted to say a huge THANK YOU for the advice on your site about always using ProPhoto RGB when editing. I've been going over some of my old D70 NEF's (which are lossy-compressed 12-bit and didn't have a lot of headroom anyway) and re-processing them with NX2 and CS3 in 16-bit ProPhoto RGB and the difference is just amazing - some images that I'd written off as unsalvageable now look quite respectable!

And as for B&W conversions... the difference is like night and day compared to working with them in any other colorspace (FWIW it's also made a big difference to my D300 NEF's - shooting lossless 14-bit files has definitely expanded what I can do with that camera).

That tip alone was worth every penny of the subscription!

I sprinkle tips throughout all my offerings, and I never know which ones readers will find most useful. Sometimes tips are so extensive and important that I turn them into a publication, as in Making Sharp Images.

I wouldn’t consider processing a Canon or Nikon DSLR image into anything other than 16-bit color with a wide gamut (ProPhotoRGB is a great choice, but any wide gamut color space in 16 bits is a big improvement over 8-bit sRGB). The gamut of digital cameras is very wide, and that of some printers is far wider than even a few years ago.

Many photographers out there have no idea what they’re missing, because they’re shooting sRGB JPEGs in 8-bit and viewing them on a display that cannot show any true red of any shade, or a saturated green, etc. The Apple 30" Cinema display is notorious for this.

If you’re shooting 8-bit sRGB JPEGs and viewing them on a typical display, you’re flying blind. Ironically, one well-known web personality who loves color does just that—he’s literally blinded himself to the one aspect of photography which matters most to himself!

Not every image can benefit from a wider gamut, but every image is better off in 16-bit color/grayscale whenever you intend to apply more than a few edits, and especially when making more aggressive changes.

Establish a workflow that doesn’t clip color in images that need a wider gamut.

Using 16-bit color (or grayscale) lets you make changes without losing subtleties in the color or tones.

Note well that using a wide gamut color space with an 8-bit depth is a bad idea, because 8-bit provides only 255 steps (256 values) between shades, which leads to banding or stepping between subtle shades of tone/color.

Finally, you’ll want to have a properly calibrated and profiled wide gamut display so as to be able to see the colors you actually have, otherwise your edits will be in error.