Before we start with this article, please make sure that you understand Color Spaces and Color Gamuts. If not, please CLICK HERE to know about them and proceed with this post.
Adobe RGB 1998 and sRGB are two of the most common working spaces used in digital photography. This post is about clarifying some of the confusion associated with sRGB and Adobe RGB 1998 and to provide guidance on when to use each working space.
sRGB is a RGB color space proposed by HP and Microsoft because it approximates the color gamut of the most common computer display devices. Since sRGB can better anticipate that how another monitor produces color, it has become the standard color space for displaying images on the internet. Actually sRGB color-gamut encompasses just 35% of the visible colors specified by CIE (see section on color spaces). Although sRGB results in one of the narrowest gamuts of any working space, sRGB gamut is still considered broad enough for most color applications.
Adobe RGB 1998 was designed ADOBE to encompass most of the colors achievable on CMYK printers, but by using only RGB primary colors on a device such as your computer display. Adobe RGB 1998 space encompasses roughly 50% of the visible colors specified by CIE — improving upon sRGB gamut primarily in cyan-greens.
Please have a look at images shown below and note how Adobe RGB 1998 extends into richer cyans and greens than does sRGB — for all tonal levels. The 50% luminance diagram is often used to compare these two working spaces, however the shadow and highlight diagrams also deserve attention.
AdobeRGB extends its advantage in the cyan-greens for the highlights, but now has advantages with intense magentas, oranges, and yellows — colors which can add to the drama of a bright sunset. AdobeRGB does not extend as far beyond sRGB in the shadows, but it still shows advantages in the dark greens.
When we talk about Printing -
All of these extra colors in AdobeRGB are good to have in a photograph, but can we actually reproduce them in a print? We see a big difference in how each printer uses the additional colors provided by AdobeRGB. The high-end inkjet even exceeds the gamut of Adobe RGB 1998 for cyan-green midtones and yellow highlights.
The printer should also be considered when choosing a color space, as this can have a big influence on whether the extra colors are utilized. Most mid-range printer companies provide a downloadable color profile for their printer. This color profile can help you achieve similar conclusions to those visible in the above analysis.
There is something called BIT DEPTH DISTRIBUTION, which we are skipping as of now.
Since the Adobe RGB 1998 working space clearly provides more colors to work with, why not just use it in every situation? Another factor to consider is how each working space influences the distribution of your image's bit depth.
Color spaces with larger gamuts 'stretch' the bits over a broader region of colors, whereas smaller gamuts concentrate these bits within a narrow region.
How can we summarize it -
Thumb rule is to understand your Photography workflow in best way and know which colors your image uses and whether these can benefit from the additional colors afforded by AdobeRGB. Ask yourself: do you really need the richer cyan-green midtones, orange-magenta highlights, or green shadows? Will these colors also be visible in the final print? Will these differences even be noticeable? If you've answered NO to any of these questions, then you would be better served using sRGB. sRGB will make the most of your bit depth because it allocates more bits to encoding the colors present in your image. In addition, sRGB can simplify your workflow since this color space is also used for displaying images on the internet.
What if you desire a speedy workflow, and do not wish to decide on your working space using a case-by-case method?
Its advisable to use AdobeRGB if you normally work with 16-bit images and sRGB if you normally work with 8-bit images. Even if you may not always use the extra colors, you never want to eliminate them as a possibility for those images which require them.
AdobeRGB clearly has a larger gamut than sRGB, but by how much? Although AdobeRGB is often depicted has having richer greens, this can be misleading and results mainly from the use of the CIE xyz reference space. This article just gives an overview and we recomend to read more about it & how it actully related to visual capabilities of human eyes.