First things first: what is a color space?
A color space is an organization of colors that allows for representations of color in both analogue and digital representations (print, screen, etc.). Not to be confused with a color model which is a mathematical model describing the way colors can be represented as numbers (e.g. three tuples in RGB or four in CMYK). For example, Adobe RGB and sRGB are two different absolute color spaces, both based on the RGB color model.
Color space conversion is the translation of the representation of a color from one basis to another. This occurs in converting an image that is represented in one color space to another color space, the goal being to make the translated image look as similar as possible to the original.
The above is a compilation from Wikipedia.
The 3 mostly used color spaces are:
- ProPhotoRGB: the largest of the three and it closely matches what your camera sensor can capture.
- Adobe RGB (1998): smaller than ProPhoto RGB, but larger than sRGB. It closely matches the gamut of CMYK printers used in the printing industry today.
- sRGB: the smallest color space of the three. It represents the color space that most monitors are able to display today.
Hohoho! Enough with the technical jargon already! Don't you agree? All you need to know in a simplified way is the following.
Processing your photos in Lightroom
When working with Raw files, Lightroom uses the ProPhotoRGB color space all the time. You don't have to worry about conversions YET. As ProPhotoRGB has the widest color information today no worries about colors changing when exporting your photos.
Now, when you are done processing your photos in Lightroom and you are ready to show the world your piece of art, Lightroom provides all 3 color spaces options to choose from: ProPhotoRGB, Adobe RGB, and sRGB.
So which color space should you select when exporting your photos?
If you are publishing your photos to the web or printing on most inkjet printers then use sRGB
If you are a professional shooting for a magazine or any commercial purpose like stock site, it is most probably that they will ask for Adobe RGB (1998)
Also consider if your printer or your neighborhood development lab uses this space then consider using it. If in doubt then go back to sRGB
Use ProPhoto RGB if exporting back and from Photoshop only.
Select the photo you want to export and go to menu File > Export.
In the Export dialogue box, go to File Settings section and set the required color space.
I tried to make this post extremely simple by just pin pointing the things you need to know when processing and exporting photos in Lightroom. If you have anything to add please add it in the comments below.