Why Adobe 1998 ?

Whilst comparing profiles of a couple of different paper types in my mac's "Colorsync Utility" I had a

browse through the other profiles available and found a few that are far larger than Adobe (1998), for

example all(?) the KODAK PHOTO CD profile, CIE RGB and the Flextight ones I have on my machine.

 

My understanding was always that Adobe RGB (1998) was the default one to use as it was the best

available and so the best way to be as future-proof as possible with any file. Seeing spaces that are larger

makes me wonder why that is so.

 

I use primarily Kodak E100G, scanned with either an X5 or a V750. I then convert the scan to Adobe 1998

which is my working space, and am currently printing out either on K3 inks to fiber gloss paper, or C-

types on Fuji Crystal archive.

 

Should I be using a better space as my default ?

 

RX

I personally favor the ProPhoto color-space for working. Remember that when using these very wide gamuts, you really need to have 16-bit files, to avoid banding.

Adobe RGB was created to encapsulate the CMYK gamut. Every color space has a different purpose. Here is a primer from Adobe: http://www.adobe.com/digitalimag/pdfs/phscs2ip_colspace.pdf

Should I be using a better space as my default?

 

Larger is not always better. If you plan on printer your files, they should be in Adobe

1998. If you are planning to show them on a monitor for the rest of your life you can use a

larger color space. Adobe 1998 give me, as a printer at a lab, the smoothest transition

from RGB to CMYK. If I am given a file that is in a larger space like ProPhoto, I will convert

it to Adobe 1998 before sending it to the printer. Converting color spaces for printing is to

me like translating a language. If your intent is to get the best transition from one to the

other, more information that is disproportional to you end goal can hinder the smooth

translation. Until printers can produce a large color space, stick with Adobe 1998.

My personal theory is that I'd rather be limited by my printing profile than by my working space. So I work in Prophoto RGB which is huge, and you should work in it with 16 bit files. Then before printing I do my gamut checking and shrink my image gamut down to be within the printer/ink/substrate's gamut.

 

Why do this? Keeps me from having to retrace all my steps if I switch to a wider gamut printer/ink/substrate in the future. With this method I just redo the steps in my workflow that are printer specific.

Ryan - what's the advantage of converting from ProPhoto to Adobe RGB and then to the printer's CMYK color-space (ex. SWOP), over simply converting from ProPhoto to CMYK?

 

Cheers,

 

Geoff S.

There is the counter argument:

 

"The same old-wives-tale about Adobe RGB having a broader range of colors has been circulating on the internet since the 1990s.

 

It does in theory, but not in practice."

 

See http://www.kenrockwell.com/tech/adobe-rgb.htm

 

N.b., in this case I'm just the messenger. A book I read before starting digital photography (http://www.123di.com/default.htm) insisted that Adobe RGB was absolutely necessary, so I've been a captive of this dogma ever since. Its just easier to keep on doing the same old twaddle than to change to something simpler.

ProPhoto RGB has the largest colorspace and allows extracting the most from a digital

capture, RAW image file, presenting the least amount of clipping and issues in the editing

process.

 

Adobe RGB has a wide color space and is the de facto standard for the CMYK printing

industry. At least three of the stock photography sites I've been looking at consider TIFF or

JPEG maximum quality files encoded and tagged with an Adobe RGB (1998) ICC as the

standard distribution for their clientele.

 

sRGB is the de facto standard used for internet and web presentation, tagged or untagged

with a profile, and is the colorspace used by low-end photographic print services.

 

I capture, RAW convert in Lightroom or Camera Raw to ProPhoto RGB for further editing in

Photoshop when needed. My standard printing process is color managed with profiles to

an Epson R2400 printer directly from Lightroom or Photoshop (their color management

facilities do whatever conversion is necessary to feed the printer with a high fidelity

image), but when I send work to external services I find out what their best printing

workflow will be and do colorspace conversion and output to the best file I can for their

needs. For web presentation, I convert colorspace to sRGB and append the ICC profile for

those few browsers that actually honor them.

 

Of course, when you do colorspace conversion, you should always check and see what's

happening to the image based on the histogram. If excessive clipping is occuring, modify

the image file to minimize it prior to conversion.

 

Godfrey

Something that I don't understand in this discussion is monitors, except for a few very

expensive ($5000+) cannot display the Adobe colorspace much less the ProPhoto RGB. How

do you edit what you cannot see?

A pixel's value is being rendered to the screen through another ICC profile transform,

similar to what happens when you output to a printer. That doesn't mean you can see it ...

the human eye itself can't simultaneously perceive 16 million discrete colors AND it adapte

far too quickly to color shifts, etc ... but using a large colorspace means that the *data*

from which the representation is derived can be manipulated more without clipping,

behind all the display transformations. Once you start clipping, you are losing data and

cannot retrieve it, and those losses become multiplicative.

 

You watch for clipping by using tools like this histogram display in Photoshop and the

saturation indicators in Lightroom. They make visible what isn't otherwise able to be seen.

 

Godfrey

One of the best books on color management is "Real World Color Management" by Bruce Fraser, Chris Murphy, and Fred Bunting. That pretty much covers everything from the theory to the practice of color management for photographers.

 

It sits next to my computer along with the equally excellent "Real World Camera Raw" and "Real World Image Sharpening" books.

Keep in mind also that large colour spaces also have the potential for a "train-wreck-photoshop-operator" to change tones to ones that are hopelessly out-of-gamut - then to make matters worse they'll display as one colour and print as another - and you'll be forever scratching your head and muttering "what the heck ..."

 

Try reproducing yellow with 100% luminosity in sRGB!

Geoff,

 

100% agreement. I keep RWCM right next to the rest of my Bruce Fraser books. He (and his

co-authors) was very good at explaining these things.

 

Godfrey

>See http://www.kenrockwell.com/tech/adobe-rgb.htm

 

Ken doesn't have a friggin clue what he's talking about here (same guy who tells you to

shot JPEG and not Raw). Don't even waste your time with this page.

 

>Something that I don't understand in this discussion is monitors, except for a few very

>expensive ($5000+) cannot display the Adobe colorspace much less the ProPhoto RGB.

 

Actually you can get a superb wide gamut display for about $1700 WITH colorimeter and

software from NEC (2690). I love it.

 

Andrew Rodney

It IS true that the wider the granularity in a color space, the harder it is to handle subtle

colors. This is why wide gamut displays that can't revert to sRGB behavior are not (yet)

ideal.

 

There are way, way more colors that can be defined in something like ProPhoto RGB than

you could possibly output, true. But we have to live with a disconnect between the simple

shapes of RGB working space and the vastly more complex shapes of output color spaces

to the point we're trying to fit round pegs in square holes. To do this, you need a much

larger square hole. Simple matrix profiles of RGB working spaces when plotted 3

dimensionally illustrate that they reach their maximum saturation at high luminance levels.

The opposite is seen with print (output) color spaces. Printers produce color by adding ink

or some colorant, working space profiles are based on building more saturation by adding

more light due to the differences in subtractive and additive color models. To counter this,

you need a really big RGB working space like ProPhoto RGB again due to the simple size

and to fit the round hole in the square peg. Their shapes are simple and predictable. Then

there?s the issue of very dark colors of intense saturation which do occur in nature and we

can capture with many devices. Many of these colors fall outside Adobe RGB (1998) and

when you encode into such a space, you clip the colors to the degree that smooth

gradations become solid blobs in print, again due to the dissimilar shapes and differences

in how the two spaces relate to luminance.

 

Andrew Rodney

Godfrey, I hear what you're saying about the the theory here. I've heard that before and, until now, accepted it. But here's my question to you: have you ever compared photos captured, processed, and printed in sRGB, to prints of the same images done in AdobeRGB or ProPhoto? If so what results? The link "Ken Rockwell" link furnished above by "Bruce C" is facinating. Rockwell is great and an expert in color. He challenges the conventional wisdom. I'd be interested in hearing your specific reaction to Rockwell's findings.

Bill,

 

I don't find Ken's comments particularly credible. I went to this workflow because it gave me

more satisfactory results ... I went from sRGB to Adobe RGB to ProPhoto RGB as my editing

colorspace as each time I went up, editability improved and my prints,of the same image

rendered from the original capture, improved.

 

Godfrey

Thanks Godfrey. If the difference can be seen in the prints, that's what I needed to know.

>Thanks Godfrey. If the difference can be seen in the prints, that's what I needed to know.

 

Keep in mind, it depends on the scene gamut and image, the encoding color space from

Raw (or scanner), the printer and colorant. Shoot a bride in a wedding dress, it will

probably easily fall within sRGB. Shoot the fall trees turning color, probably not. And with a

good converter (Camera Raw), you can see the effect of gamut clipping as you toggle from

sRGB to Adobe RGB (1998) to ProPhoto RGB. LOTS of scenes fall outside Adobe RGB

(1998)! And we know the gamut of many modern ink jets exceeds Adobe RGB (1998).

Epson is just releasing a new set of printers with vivid magenta that pushes this even

farther than when Ken wrote that nonsense a year ago (back then, K3 inks exceeded

Adobe RGB gamut anyway).

 

Andrew Rodney