Need help understanding color on the Mac

Baldy

So I work for smugmug and see a lot of help email. Usually, adding a feature or help section, or changing the UI makes them go away for a particular topic.

A common one right now is "why don't my photos look the same when I post them online as they do on my Mac?" I haven't found a good online resource to answer that question -- can someone point me to one or do I have to write it?

If I have to write it, I have to completely understand it, which I don't yet.

The part I get is photos for the web need to be in sRGB, the color space of the web. And sites like ours strip our the ICC profiles for display copies because they make the photos bigger and most devices don't use them anyway.

I also get that most Macs come with gamma set at 1.8, where Apple recommends it, but the sRGB web standard is 2.2.

What else is going on? I just noticed on my Powerbook that going into display preferences > color yielded 3 choices and mine was defaulting to LCD. It made DGrin look like shades of brown when I knew I had chosen gray colors. When I swiched to sRGB, and set the gamma to 2.2, it looked like it does on my XP box.

Is that all there is? What about the working space in Photoshop?

wxwax

My technical answer comes in two parts.

1/ I hear things look brighter on Macs than PCs.

2/ If a photo's color corrected to perfection, but virtually nobody sees it as it was intended to be seen, does it exist?

fish

wxwax wrote:

My technical answer comes in two parts.

1/ I hear things look brighter on Macs than PCs.

2/ If a photo's color corrected to perfection, but virtually nobody sees it as it was intended to be seen, does it exist?

It's easy to tell that it's 2:30am in Georgia. :lol

komet

fish wrote:

It's easy to tell that it's 2:30am in Georgia. :lol

Kinda like the tree falling in the forest thing.

zero-zero

Baldy wrote:

The part I get is photos for the web need to be in sRGB, the color space of the web. And sites like ours strip our the ICC profiles for display copies because they make the photos bigger and most devices don't use them anyway.

Baldy,

I wish I could stick around longer for a full explanation but can't right now. However, here's some pointers:

sRGB ain't "the color space of the web" - in fact, there ain't such a thing as a color space for the whole WWW. Images with ICC profiles embedded will show up correctly in ICC-savvy web browsers (available for the Mac only the last time I checked), and with varying degrees of departure from proper color in other browsers, subject to behavior and calibration of the display used and how color parameters are setup in the OS. This is clearly different from "everything being sRGB". The web is in itself untagged and devoid of an inherent color space.

Recommendation to use sRGB in web graphics derives only from the fact that crapola displays have less of a struggle displaying it, because it is so small in gamut (has few colors, so to speak). However, if you're grabbing every correctly tagged image using, say, Bruce RGB or Adobe RGB and convert it to sRGB or, worse still, simply rip away the ICC profile and assume sRGB, you're doing a great disservice to the pic, because it will now be impossible to view it 100% correctly (because of the profile mismatch), and you might have irrecoverably clipped those colors outside the sRGB gamut. Moreover, it will also be impossible to print it correctly, because either your home inkjet or Wal-Mart's Fuji Frontier need a correctly assigned ICC profile to be able to recreate the colors as intended. A mismatched profile will only make things worse, it would be akin to giving someone a book in Portuguese and telling him to translate it from Galician (a language similar but not equal to Portuguese) to English - you can see it's not the way to do it, no?

You should consider keeping the ICC profiles embedded in the pics, after all, they are only what, 4kb? Things won't be any worse for those that can't deal with them, but much better for those that can.

Oh, by the way: ICC calibration and profiling takes priority over generic platform-wide settings, so a properly tagged image will look exactly the same in a Windows machine or a Mac or a Linux box or a Symbian cell phone, provided they are being viewed in an ICC-savvy application.

More later. I'd suggest you email me privately, if you want, for a longer discussion about this that may go beyond the realm of Dgrin.

lynnma

zero-zero wrote:

Baldy,

I wish I could stick around longer for a full explanation but can't right now. However, here's some pointers:

sRGB ain't "the color space of the web" - in fact, there ain't such a thing as a color space for the whole WWW. Images with ICC profiles embedded will show up correctly in ICC-savvy web browsers (available for the Mac only the last time I checked), and with varying degrees of departure from proper color in other browsers, subject to behavior and calibration of the display used and how color parameters are setup in the OS. This is clearly different from "everything being sRGB". The web is in itself untagged and devoid of an inherent color space.

Recommendation to use sRGB in web graphics derives only from the fact that crapola displays have less of a struggle displaying it, because it is so small in gamut (has few colors, so to speak). However, if you're grabbing every correctly tagged image using, say, Bruce RGB or Adobe RGB and convert it to sRGB or, worse still, simply rip away the ICC profile and assume sRGB, you're doing a great disservice to the pic, because it will now be impossible to view it 100% correctly (because of the profile mismatch), and you might have irrecoverably clipped those colors outside the sRGB gamut. Moreover, it will also be impossible to print it correctly, because either your home inkjet or Wal-Mart's Fuji Frontier need a correctly assigned ICC profile to be able to recreate the colors as intended. A mismatched profile will only make things worse, it would be akin to giving someone a book in Portuguese and telling him to translate it from Galician (a language similar but not equal to Portuguese) to English - you can see it's not the way to do it, no?

You should consider keeping the ICC profiles embedded in the pics, after all, they are only what, 4kb? Things won't be any worse for those that can't deal with them, but much better for those that can.

Oh, by the way: ICC calibration and profiling takes priority over generic platform-wide settings, so a properly tagged image will look exactly the same in a Windows machine or a Mac or a Linux box or a Symbian cell phone, provided they are being viewed in an ICC-savvy application.

More later. I'd suggest you email me privately, if you want, for a longer discussion about this that may go beyond the realm of Dgrin.

No no, don't go away, I was just getting into it.. I think many of us would be extremely interested in what you have to say. Even a tutorial on the subject..(I love tutorials). Thanks a lot zero.
Lynn

Baldy

zero-zero wrote:

You should consider keeping the ICC profiles embedded in the pics, after all, they are only what, 4kb?

I wish we could but unfortunately the average thumbnail sized-image on smugmug is 2.5k, so including the profile more than doubles the size. And since 90% of the images served are thumbs, everyone notices a slowdown when we embed the profiles. Their caches get bigger, their memory usage goes up, etc.

Add to that the fact that 90% of devices that browse our site are Windows-based and IE on Windows is not ICC-aware. So lugging the ICC profiles around seems to benefit the few who have ICC-aware browsers and speedy connections and aren't worried about memory or disk usage.

css, html, Windows, IE, television and handhelds all default to IEC 61966-2-1, which is defined here.

The final issue is most of the online printers have gone to sRGB so that generally what you see on a Windows machine on your screen is what you get. We use EZ Prints because they're so popular among our pros, and they publish their profile but it's sRGB.

Which brings me back to the Mac, whose heritage seems to be high-end print, so the gamma is set to 1.8 instead of sRGB's 2.2, and the white point has a different color temp.

I found a pretty good page a minute ago, http://www.shootsmarter.com/infocenter/wc007.html , which suggests the following:

Portrait/wedding/seniors shooters use sRGB
Editorial/commercial/advertising shooters may want to select Adobe RGB (1998)
Set gamma to 2.2

I guess I'd conclude that if you're doing web graphics for the masses, use sRGB and gamma of 2.2.

Your thoughts.

fish

Baldy wrote:

I guess I'd conclude that if you're doing web graphics for the masses, use sRGB and gamma of 2.2.

Your thoughts.

I think this oughta be in a FAQ.

DavidTO

Baldy wrote:

I guess I'd conclude that if you're doing web graphics for the masses, use sRGB and gamma of 2.2.

Your thoughts.

I just made a new calibration profile for my mac at 2.2, and I'll see how it goes.