sRGB vs Adobe RGB

[Ruchika_2011]

What is the difference between the two color spaces except for the color gamut. What I understand is that sRGB is standard color space designed to work with almost all display units and is common man's take to keep away from color management. Adobe RGB on the other hand offers a larger playground to the photographers and thus enables them to print more accurate and true colors. What are the other differences between the two color spaces?

[teaking]

The difference between sRGB and aRGB is what the numbers represent.
If you imagine a grid and every 10cm there is a dot that dot is a colour and your only allowed 10 dots, that’s how many colours you can represent. If you space those colours wider apart 20cm with 10 dots you can now represent a wider array of colours. But you can still only show as many colours.
So what your doing is allowing a wider range of colours to be shown, with todays RAW data and bit depths the amount of colours you can display means banding issues are no longer as big of a problem as you can represent smooth transitions easier as you have more available colours in your pallet.

In terms of showing truer colours in a sense thats incorrect as a well colour managed setup will show the colour on your screen as well in both profiles. If you mean colours you see in everyday life are not representing in sRGB I believe there are a few colours that your camera can record that cant be displayed in sRGB but there really not that noticeable unless your looking for them however I don’t know that for sure I hope someone else can offer a better explanation there.

To rap it up though your display device is what is important, many people look at pictures in colour managed browsers and viewers and say how much better aRGB looks but there looking at these images on sRGB devices so there seeing an sRGB representation of an aRGB image, in terms of future proofing the best alternative is to keep your RAW file that doesn’t have a colour space your not pigeonholed in anyway if you have a colour managed setup and your comfortable with profiles and the labs your using accept aRGB consider it an option, other wise I would stay on the side of caution and stick with sRGB you could loose more than you could gain.

Hope that may have helped.

[bigwater]

Just because your viewing the image on a monitor does not mean that it is automatically in srgb but srgb is the default color space for most monitors and cameras. My camera has the ability to capture raw photos in either srgb or Adobe rgb. Because Adobe rgb does have a much larger color gamut I use that and then convert to srgb for web or cmyk for print. If you have Photoshop look at the gamut warnings to give you some idea of what colors are out of gamut in a particular image.

[ravncat]

That's pretty much it, especially with what is written above.

The two color spaces are like maps to your photograph - but each map is in different units, say kilometers and miles. If your file isn't correctly tagged and it uses the wrong units you'll get differences in the display of the colors of your image. - the map (color space) is read wrong.

The real difference, is also in the size and detail of the maps - the different color spaces have different ranges of color - and adobe RGB is a map with finer units and over a larger "set" of colors ( it's a larger space than sRGB).

There are still issues with printing - as printers don't really print in RGB (some do, but not in adobe or srgb, they have yet again their own color space). Most printers, especially those that you buy, are in a CMYK colorspace.

Something else - I think called a CMM color management module (it's been awhile since i've had to use the terms ) converts the units and dimensions from one map to another. That's what color management is really about. Your computer has a basic one, photoshop has one, and sometimes your printer has one. It's your job to select which to use. (you'll find something somewhere in photoshop printing that says "let photoshop manage colors vs let your printer manage colors)

There's two more gotchyas* one of which is the CMM just converts units from A to B - but there are a few ways to do it. These differences have to do with "other differences" between the color spaces. (and hence put us back on your question). They are the rendering intent. Sometimes one color space has Hue, Saturation, Lightness combinations (colors) that don't exist in the other colorspace. How do you deal with them? You can squeeze the colors together - lop them off and pretend they're all a certain color (ie all maroons that are slightly purple at one point on the map are just, maroon) You may or may not want to keep blacks at a certain point.

The general ways in which you must tell the conversion to work are generally labelled as rendering intents. Your choices are usually "Perceptual" " Relative" "Absolute" and "saturation" (these will vary slightly among programs.) Perceptual and Relative are the most "photographic" Absolute and saturation are more important in graphic design.

You can google perceptual or relative or read the photoshop notes if you want more information about them. which to use depends on factors in your photographs (such as if your picture colors are in or out of the final color space)

*the other gotchya for printing is using the CMM twice - imagine converting from kilometers to miles, and then doing it again a second time - using your correct number for miles and converting them again as if they were kilometers - you'll get the wrong answer. This is why you need to make sure you are using CMM only once - and have to tell the printer driver "do not manage colors" when photoshop is managing colors. - this is also why some people have better luck with letting the printer manage colors - they didn't know they were having the printer and photoshop manage colors at the same time...

[teaking]

Originally Posted by bigwater

Just because your viewing the image on a monitor does not mean that it is automatically in srgb but srgb is the default color space for most monitors and cameras. My camera has the ability to capture raw photos in either srgb or Adobe rgb. Because Adobe rgb does have a much larger color gamut I use that and then convert to srgb for web or cmyk for print. If you have Photoshop look at the gamut warnings to give you some idea of what colors are out of gamut in a particular image.

Sorry if I mislead anyone there what I meant was most people are viewing images on a monitor that is most like an srgb device by that I mean it is not a wide gamut monitor and is profiled as such so even though an argb image is being displayed in a colour managed application the reality is whats really happening is either in the os or program the colour management is giving a representation of argb on the srgb device so your viewing colours available in srgb. I guess I was saging know the limitations of your output devices.

[ErikUngerPhotography]

Originally Posted by bigwater

My camera has the ability to capture raw photos in either srgb or Adobe rgb.

I am pretty sure that the RAW file doesn't actually have a color space until you process it, which can be done in LR or ACR. The in camera selection of sRGB or aRGB is only applied to the jpeg.

Also, if you use LR3, the native color space is Pro Photo RGB and has a much wider gamut even than aRGB. I'd recommend assigning the Pro Photo RGB if you are shooting RAW, and then export as needed when you are finished.

[bigwater]

Originally Posted by ErikUngerPhotography

I am pretty sure that the RAW file doesn't actually have a color space until you process it, which can be done in LR or ACR. The in camera selection of sRGB or aRGB is only applied to the jpeg.

.

That's right my bad

[autofocus]

You also may want to see what your lab requires. A while back I had changed from sRGB to Adobe RGB thinking I'd get better results from my lab. Needless to say the images were all coming back dreadfully murky looking, and it took a while for me to find out what was causing it. Apparently, our lab wants sRGB for prints, and I believe many other labs also want it that way. I guess it boils down to if you don't understand what the ramifications of what you are doing, it's best to leave it alone