Tuesday, January 17, 2006

Smugmug: just use sRGB and be happy

SmugMug is a digital photography site that serves both pro and amateur customers. They review the pros and cons of color profiles and come down on the same side of every intelligent review I've read -- use sRGB for printing.

I take that to the next logical step -- unless you really, really, really know what you're doing, use sRGB as your working color profile. Here's what they wrote. I had not seen the references to photo printing papers vs. ink jet printing. I wonder if the newer non-ink printers change their answers? (emphases mine)
smugmug - help - srgb versus adobe rgb 1998

The box of crayons you're given for displaying photos on the web is called sRGB.

There are other color spaces, such as Adobe RGB (1998), but no Windows-based browser can display them correctly. The Macintosh browsers Safari and Internet Explorer can, but only under unusual circumstances not seen in everyday browsing. [jf: probably if you change the color profile for your monitor to Adobe]

To your right you see the same photo displayed in sRGB (above) and Adobe 98 (below). You'll notice the Adobe version is washed out and pixelated in some areas. There is no way around this problem other than to convert your files to sRGB.

... In theory, Adobe 98 is broader, encompassing some colors sRGB doesn't, like the pure cyan in HP's original logo. In practice, for photographic prints, it offers fewer colors.

Suppose you take an art class and the teacher gives you 3 boxes of crayons: 256 red ones, 256 green and 256 blue. She calls them Adobe 98 and you notice some spiffy colors that the poor guy next to you doesn't have. He also received 256 red, 256 green, and 256 blue crayons, but they're labeled sRGB. [jf: 256 sound familiar? That's our old friend, 2**8. Aka 8 bit color space.]

The teacher then drops a bomb: you're not allowed to use the outer rows of crayons in your boxes because she thinks they're too gaudy for the landscapes you'll be drawing today. The person next to you can use all his crayons because none of them represent those gaudy colors. Now who has more crayons at their disposal?

Photographic paper and chemicals do not allow you to use all the colors of Adobe 98. For that reason, the sRGB tide has swept North American printers. The top labs, such as whcc, MPIX, EZ Prints (our lab), Shutterfly (whom we used to use), Kodak, Fujifilm, Photobox, Costco, Snapfish, Wolfe's, etc., all expect your file to be in sRGB and if it isn't, your prints will look washed out.

Yikes! What colors do I give up?

In our experience, 99 of 100 prints we see are completely represented by the colors of sRGB, including stunning landscapes on exhibit in galleries and shows. We've all been viewing photographic prints for decades and are often in awe of the vibrant colors we see in them. In addition, virtually every stunning photo you see on the Internet is painted with the colors of sRGB, because it's the only choice.

If a specific area of the shot is not covered by sRGB, such as day-glo colors, color substitution occurs when you or your camera creates the sRGB file. Rare is the person with a fine enough eye to notice.

Then... What's Adobe 98 good for?

Ink jet prints. Certain ink jet printers that have many ink cartridges can paint colors photographic prints cannot. In fact, some ink jet printers span so many colors that photographers use ProPhoto RGB. Also, many companies who print brochures and other offset-press materials may ask for your files in Adobe 98.

But Adobe 98 has the same number of crayons as sRGB, so by reaching out to more colors, you're sacrificing fine increments that are so important in shadow detail, for example. Not true of ProPhoto RGB, which unlike Adobe 98 and sRGB, is a 16-bit color space.
[jf: So it's not worth fussing with Adobe 98, but sometime in the future ProPhoto RGB might be of interest. I think JPEG can't handle that color space, but DNG certainly can.]

How do you answer the experts who disagree with you?

Here are two well-intended statements from great authors that have ruined the prints and online displays of many good photographers:

If your work is destined for print, then sRGB is a very poor choice indeed.
— David Blatner and Bruce Fraser

sRGB is fairly ghastly for photographers. I wouldn't even recommend it for web designers.
— Scott Kelby

... The practical reality is the web can only display sRGB files and 99% of commercial prints are produced through labs that only accept sRGB files.

Q: I've seen examples online of Adobe 98 files that show more color range than sRGB files.

A: These are terribly confusing to most people because they are sometimes offered by respected names. Every example we've seen, however, displays sRGB files pretending to be Adobe 98 files, because sRGB is the only display option on the Internet.
[jf: I'm not sure this is entirely true, though they repeat it often enough. I think Firefox respects color spaces, and IE 7 probably will. OS X Tiger and Safari do well.]

No less an authority than Rob Galbraith did that in an article on Microsoft's site.

Q: The printer I've used for years accepts Adobe 98 files. Why don't you?

A: We are considering doing what they do: converting your Adobe 98 files to the narrower color space the printer/paper/chemicals can handle. Converting from a broader color space to a narrower one involves decisions about color substitution. If you've read this far, you're probably fussy about color. Do you really want to lose control of those decisions?
The last statement is interesting. They're saying sites that claim to accept Adobe 98, so as to attract discerning customers, are in fact slyly converting to sRGB on the back end. Hmmm.

2 comments:

Chris MacAskill said...

I'm the guy at SmugMug who wrote that stuff :-) and just wanted to clarify that sRGB is the only choice for display on the web, and a good choice for commercial prints on printers like the Fuji Frontier.

But for inkjet prints if you have a shot with very vibrant greens and blues, Adobe 98 is probably better.

Here's a great article that compares the two:

http://www.cambridgeincolour.com/tutorials/sRGB-AdobeRGB1998.htm

Hope this helps.

Chris MacAskill

John said...

Thanks Chris! Great comment. I get the impression that some high-end home printers now surpass the output of most commercial printers.

I do like smugmug though, I find myself using SmugMug more all the time.

I'm starting to do Canon RAW processing, so I might eventually migrate beyond sRGB as I get fancier, but for now I'm sRGB. Maybe when Aperture gets to version 1.11 ...