The post Camera Color Spaces Explained – sRGB vs Adobe RGB vs RAW appeared first on Digital Photography School. It was authored by Herb Paynter.
Your camera is probably able to capture color images in a variety of different color containers called “spaces.” These camera color spaces collect colors in one of several size light buckets labeled sRGB, AdobeRGB, and RAW.
Each bucket gathers slightly increased varieties of light, similar to the way Crayola crayons are packaged and sold in increasingly inclusive collections of colors; small, large, and jumbo.
Camera color spaces offer photographers a variety of different size boxes.
Camera color spaces
A debate in the photo community usually arises over which camera color spaces to choose in the camera’s preferences. Some color spaces capture more of the hues and saturated colors than others. Pictures captured in one space may include more colors than another.
Each space is ideally suited for certain purposes, and the question of which camera color space to choose needs a bit of explanation. In addition to the capture question, choosing a color space for post-production editing will depend on the image’s ultimate usage.
Your camera’s color spaces involve not just color data, but additional parking space on the drive. Larger color spaces provide more bit-depth (explained below), which occupies more digital real estate on the memory card. So, the choice of which to use does have practical importance.
What camera color space to use
There is no singularly perfect color space choice, so let’s examine which is best for specific situations.
Unless the sole purpose of a photo is to display as a high-resolution digital image, you might want to convert the file’s original color space for a less demanding result. However, keep in mind that every time a file mutates from a larger color space to a smaller color space (RAW to AdobeRGB, or AdobeRGB to sRGB), the image’s color intensity and integrity may diminish in the process. Some imaging applications are less demanding than others.
While copies of digital files remain identical in size and intensity to the original regardless of how many times they have been copied, when a digital file mutates to a lesser color space, it will always lose some critical color information. Your camera color spaces in general, and device color spaces, in particular, are all unique. Each serves a particular purpose.
It’s a matter of depth
The difference between camera color spaces boils down to an issue called bit depth. Bit depth is a mathematical description of how many visible distinctions between shades of color can be recognized and reproduced by different devices (a techie term for scanners, cameras, computer monitors, and printing machines). Unfortunately, not all devices can reproduce all colors the same (which is the primary stumbling block amidst all color issues).
Every device reads and reproduces color using a different process. While this sounds like a fixable problem, there is a sad and unsolvable reality behind the problem. There are at least three different interpretations of color at play in every capture-display-print cycle.
First, cameras capture color by recording intensities of light as electrical signals and interpreting those signals as colors. Each color is assigned a specific number.
Second, these numbers are then sent to the computer. Here, they get translated into another process that interprets those electrical signals into a process that turns on tiny lights (called pixels) on a backlit screen.
And third, those pixels are then sent to a printing machine that instructs those pixel values to spit tiny splatters of colored ink onto paper.
It’s a very complicated process that color scientists have tried for years to make simple. Unfortunately, it just ain’t that simple!
Anyway, during this hair-on-fire digital transition, different methods are employed that utilize the various color spaces in a way that transforms the colors from one device to another as accurately as possible. Sometimes the color translations don’t convey the colors as accurately as we would like, which is why sometimes the monitor colors don’t match the printer colors.
The ultimate referee
The only comprehensive color space that plots the full scope of what the human eye can see is what the science community calls L*a*b* (inverted horseshoe diagram) space.
The human eye is the ultimate arbitrator in the color wars, and all device capabilities (camera, display, and printer) are defined by how they match up to the eye’s master gamut. This is why this strange horseshoe shape is referred to as the Reference Space. All other devices, whether camera, display, or printer, can only recognize and utilize portions of this “reference space,” and they usually disagree with each other.
Color is a very diverse and dysfunctional family. Each device speaks a different dialect of a similar language. Each produces colors that cannot be faithfully reproduced on other devices. Color is a very messy topic.
Some devices can express color more completely than others. Unfortunately, no device created by humans can reproduce all the colors that can be seen by humans. Also, the colors captured by one device that fall outside the gamut (Crayola box size) of other devices, get clipped, lost, or compressed during the handoff. Those colors never come back home.
This is the tragic truth about digital color reproduction. The trick to color reproduction is in retaining as much of the common color as possible during the process. Fortunately, this same human eye (and brain) are very forgiving about accepting the limitations of non-human devices.
Color reproduction is a true application of the law of diminishing returns and the visual science of physics. Photographers understand this law quite well.
Very rarely can a camera actually capture all the color and dynamics of an original scene. Moreover, nature’s color gamut extends even further than the colors that the human eye can identify. Any time a digital image gets transposed from one form into any another form, that transformation is a diminished-value exchange.
As an image is transferred from one device to another, those pixel values located outside the color gamut of the destination device always get lost in the translation. The object of color management is to mitigate color loss and maintain as much of the appearance of the original as possible, all the way through the reproduction process.
RGB spaces (sRGB, AdobeRGB, ProPhoto RGB)
It all begins with the camera’s color settings that are in place when you capture the scene. All cameras capture light through red, green, and blue filters (RGB color space). While there are a number of RGB color spaces to choose from, each sports a slightly different color gamut.
Each color space (sRGB, AdobeRGB, ProPhoto RGB, etc.) provides a unique collection of color attributes, and each space satisfies specific display and reproduction requirements.
Gamuts are descriptions of the range of colors that a device can recognize, record, display, or print.
Shooting a vibrant, saturated scene with the camera requires a larger color space. Using a camera color space with a smaller gamut could significantly diminish the raw, harsh emotion of the scene. This is why most photography experts encourage photographers to set their cameras to capture images in AdobeRGB.
sRGB
Almost all digital cameras are factory-set to capture colors using sRGB as the default color space for a plausible reason; most of the pictures we take never get printed! At best, we view them on computer monitors or social media. Quite honestly, most of the pictures we capture never make it past the initial glance at the camera’s LCD screen. Capturing those images in higher-bit color space is a total waste of disk space.
sRGB was developed by HP, Microsoft (and others) back in the early days of television to address the color gamut needs of most televisions (early versions of computer monitors), and the standard was set long ago. The airwaves and Internet browsers live on an sRGB diet. As such, the sRGB color space standardizes the way images are still viewed on monitors and televisions.
Adobe RGB
If the ultimate destination for your picture is monitor or display-based presence (presentations, Internet, or television displays), this is probably the best choice to capture images. However, if you shoot for print on paper, both AdobeRGB 1998 and ProPhoto RGB RGB contain a wider gamut of colors and are thus more suited for preparing images for print.
RAW
Actually, the most ideal bucket for capturing images actually exceeds the gamuts of all three of these camera color spaces. I’m speaking of course of your camera’s ability to capture images in RAW format. This is a format that supersedes any defined color spaces.
RAW files capture color in the highest bit depth possible; up to 14-bits per color. RAW is not an acronym; it is more of a description. It is the recording of all the limited color depth and uncompressed dynamic range of the original scene. Start RAW and strip down from there.
Camera color spaces explained – Conclusion
Congratulations on sticking with this article through all the minutia.
By now, it probably seems like camera color space is more like outer space, but it doesn’t have to remain this technical. Simply remember to capture images in RAW format (perhaps in addition to capturing them as JPG) and then transform the colors down the chain of reproduction as the need dictates.
Edit images in the camera color spaces of ProPhoto RGB or AdobeRGB to retain as much color elbow room as necessary. Those images destined for print should be transposed to AdobeRGB, and reduce those images destined for the Internet or slideshows to sRGB. Simple, enough!
The post Camera Color Spaces Explained – sRGB vs Adobe RGB vs RAW appeared first on Digital Photography School. It was authored by Herb Paynter.
You must be logged in to post a comment.