"Working" Color Space - sRGB, Abobe RGB, and ProPhoto RGB

Good questions Sathi..... simple and complicated all at once . For those that are very demanding of 100% right on color matching (not me, I'm pleased with something pretty close) I believe there are printer/paper/ink profiles that allow for EXACT color matching.

For most of the rest of us there is monitor calibration, done with either software tools like Adobe Gamma (mediocre at best) or hardware calibrators (best method) like the Eye One and other hardware devices. I use a hardware calibrator and get things pretty close.

There is also the method of having the lab send you a standard print and the file that goes with it. This way you can do a "stare and compare" between what you see on the screen and what you're holding in your hand.

Printing yourself a 4x6 "test strip" may or may not work out depending upon the consistency and reliability of the pros at your commercial lab.

Sathi wrote in post #3035063
Can someone shed some light on this for me...

If your printer can print colors that the monitor cannot display, and you use a colour space that allows it to take advantage of those colours, how are you suppose to know what your print will look like and how can you account for what your output will looks like when you do certain things in photoshop like increasing saturation? Just print up a 4x6 and see if it looks ok and then go from there?

Now somebody help me out please. What is Pro Photo RGB ? I don't get out much and have not done any experimentation with LR.

Is that something new that lightroom has recently come up with? I thought the major "players" were sRGB and aRGB. What does Pro Photo RGB give us that the others don't? - Stu

What about ProPhotoRGB?.

Thank you for the link Rene - interesting read; it explains things in fairly clear terms.

Clear enough terms that I don't see myself realistically using it for the type of work I do, which is wedding, social event and some (not huge) landscape and street photography. For all of the above and my lab sRGB serves my clients and myself quite well. I don't use aRGB now so cannot imagine considering ProPhotoRGB for my workflow.

The seminar I attended discussed aRGB and gave me a sense of just how LARGE a color space that is. And Pro Photo RGB is even larger yet.

René Damkot wrote in post #3035173
What about ProPhotoRGB?.

I checked the color space diagrams for the Noritsu 3101, Fuji Crystal Archive Type 1 Lustre (which they have at Costco) and it exceeds sRGB in the yellow and blue dimensions. It's even more than Adobe RGB, though ProPhoto covers everything. You'll need a VRML plugin to view the three-dimensional gamut.

http://www.drycreekpho​to.com …&TC=74&Submit=B​uild+Model

Given that, I usually export from lightroom in sRGB because Elements 2 won't handle 16-bit color.

Oops, I had meant to post that earlier but René already answered...

FYI, it seems a good idea to use sRGB if you're output is 8-bit, otherwise it seems you're spreading a limited number of colors over a larger colorspace.

ProPhoto RGB contains colors beyond the range of human perception!

Not too mention that aren't you going to end up with absolutely HUGE files? it takes me a fair amount of time now to FTP my sRGB JPG's to the lab via DSL. And they are about 3-6MB each. I could only imagine what would be required for ProPhoto RGB.

ohtoberich wrote in post #3035692
............FYI, it seems a good idea to use sRGB if you're output is 8-bit, otherwise it seems you're spreading a limited number of colors over a larger colorspace.

ProPhoto RGB contains colors beyond the range of human perception!

sapearl wrote in post #3035810
Not too mention that aren't you going to end up with absolutely HUGE files? it takes me a fair amount of time now to FTP my sRGB JPG's to the lab via DSL. And they are about 3-6MB each. I could only imagine what would be required for ProPhoto RGB.

Why would your file sizes change because of color space? The file is essentially still the same, just a different "code" for the information. 8-bit to 16-bit should change the size, but I am not sure about color space.

you work in prophoto in LR no matter what. I choose to work in it in PS too, but thats it, you don't send that to anyone or print it directly, you still convert to sRGB for sending out or convert to the ICC profile of the printer.

Well, maybe my understanding of this is screwed up then and I'm mixing my 8-bit and 16-bit files here for a bad comparison.

I guess I assumed that the ProPhoto RGB file would be 16-bit (maybe this is where my mistake is) which would be WAAAAY bigger than the 8-bit sRGB file that I generate.

In2Photos wrote in post #3035838
Why would your file sizes change because of color space? The file is essentially still the same, just a different "code" for the information. 8-bit to 16-bit should change the size, but I am not sure about color space.

sapearl wrote in post #3035875
Well, maybe my understanding of this is screwed up then and I'm mixing my 8-bit and 16-bit files here for a bad comparison.

I guess I assumed that the ProPhoto RGB file would be 16-bit (maybe this is where my mistake is) which would be WAAAAY bigger than the 8-bit sRGB file that I generate.

No you might be right. I don't know, that is why I asked. Hopefully someone can answer this for us.

sapearl wrote in post #3035115
Good questions Sathi..... simple and complicated all at once . For those that are very demanding of 100% right on color matching (not me, I'm pleased with something pretty close) I believe there are printer/paper/ink profiles that allow for EXACT color matching.

For most of the rest of us there is monitor calibration, done with either software tools like Adobe Gamma (mediocre at best) or hardware calibrators (best method) like the Eye One and other hardware devices. I use a hardware calibrator and get things pretty close.

Thank you for your response. I am with you, I am not obsessed with 100% accuracy. And I don't expect to much as I calibrated using Adobe gamma and work under incandescants. If the print comes out looking good and reasonably close to my original intent I am happy. Especially considering my monitor is glowing light and my printer sprays dye onto a piece of paper i'm amazed its even as close as it is.

Having said that I have a problem

I convert all my pictures from raw into aRGB which is also my working space under photoshop. I used to print directly from photoshop to my canon i960 and I remember the prints being a very close match. I have recently picked up a pixma 9000 pro. If i convert the image to srgb, change the mode from 16 to 8 bit, and save as a jpg canon easy photo print gives me an image that is an almost spot on match with the screen. If I print as is with no convertsion I get very oversaturated colours.

Since I tend to be Johnny oversaturation to begin with, this added vibrancy makes the pics look cartoonish. Its a PITA to convert to sRGB and canon recommends I print with aRGB, any ideas?

A few things I should mention:

1) Greens seem to be the most effected. Is this maybe because my i960 didn't have a green tank and just wasn't able to print my whacked settings to their fullest suck potential?

2) My server and my workstation both run linux. I have windows XP running on the server as a virtual machine in vmware so I can print with the canon driver. On my work station I am printing to the server with photoshop running under a virtualized XP as well. I'm not sure if that could have any effect even though I doubt it.

OK - it's starting to slowly sink into the old slow brain. Thanks Corey. I was not even aware it was an option in PS which is what I use. I'd set up my parameters once and don't usually look at those menus. But now you've all got me curious.

coreypolis wrote in post #3035856
you work in prophoto in LR no matter what. I choose to work in it in PS too, but thats it, you don't send that to anyone or print it directly, you still convert to sRGB for sending out or convert to the ICC profile of the printer.

sapearl wrote in post #3035875
Well, maybe my understanding of this is screwed up then and I'm mixing my 8-bit and 16-bit files here for a bad comparison.

I guess I assumed that the ProPhoto RGB file would be 16-bit (maybe this is where my mistake is) which would be WAAAAY bigger than the 8-bit sRGB file that I generate.

What I got out of my research on ProPhoto RGB is that it really needs to be used in a 32 bit environment to avoid certain problems associated with spreading the gamut too thinly over 16bit.

Regarding color matching using the Adobe RGB - if you've got wads of cash you don't know what to do with (perhaps you already own the entire L lineup?), you can get monitors that cover the entire aRGB gamut.

For only $5,000 USD you can get an NEC Diamondtron 22" CRT, which handles more than 97% of aRGB.

Of course, if that's not good enough, there's always the Eizo Coloredge 22" LCD that does 100% of aRGB, and will only set you back $6,000 USD.