Lightroom supports 3 different colour spaces:

  1. sRGB
  2. AdobeRGB
  3. ProPhotoRGB

With the sRGB being the smallest colour space and ProPhotoRGB being the widest colour space. So which one to use? The real answer is to use the colour space that matches the colour space of the display.

  • All “real/professional” printers supports ProPhotoRGB.
  • No email program supports either AdobeRGB or ProPhotoRGB.
  • No web browser supports either AdobeRGB or ProPhotoRGB.
  • No photo frame supports either AdobeRGB or ProPhotoRGB.
  • No DVD viewer supports either AdobeRGB or ProPhotoRGB.
  • Most simple photo viewers programs only support sRGB.

So why not just output photos in ProPhotoRGB and let them see it in sRGB by whatever application? Because of the various problems this will cause:

  1. You don’t know how the application will do the conversion from AdobeRGB or ProPhotoRGB to sRGB.
  2. Many applications do a very poor job of converting from AdobeRGB or ProPhotoRGB to sRGB. This means many clipped whites, unwanted colours, colour casts…
  3. There are already too many variables when displaying the photos on a customer computer, such as screen size, calibration, screen brightness…

If you want to email photos or display them on the web, export the photos as JPEGs using the sRGB colour space.