# Color Space Question



## domromer (Feb 29, 2008)

I'm totally confused about color spaces.

At first I never worried about color space, then I'd upload pics to the web and they'd look like crap. So I read the web is srgb so I converted everything to srgb. Which is fine as long as I'm sending things to the web. 

Now I needed to start printing things. It seems commercial printers use srgb while inkjets use cmyk. 

So what the heck should my color space be? I just read an article in pop photo and they use adobe rgb I didn't hear them mention cmyk at all.

If I put everything to adobe rgb, when do I convert it to srgb before I send it to web? Will I see the colors change is PS when I convert to srgb from adobe rgb? Will I need to make color adjustments when sending things to the web?

Like I said I'm totally confused. Could someone please shed some light on this subject for me.


----------



## Helen B (Mar 1, 2008)

Most inkjets behave to the outside world as if they are RGB devices (ie they want RGB data), and they are profiled as RGB devices, even though they use CMYK inks. Working in RGB is OK.

I use Adobe RGB (1998) as my working colour space and then convert to sRGB for the web and for the printing services that don't accept Adobe RGB. 

sRGB is a smaller (ie it contains fewer colours) colour space than most inkjet printers are capable of.

Best,
Helen

Later:

_"If I put everything to adobe rgb, when do I convert it to srgb before I send it to web? Will I see the colors change is PS when I convert to srgb from adobe rgb? Will I need to make color adjustments when sending things to the web?"_

I usually do my conversions immediately before doing the output sharpening, so my last two steps are colour space conversion and then sharpening.

You probably won't see the colours change when you do a conversion. You just loose some of the colours that your monitor probably can't display anyway. The colours change if you simply change the colour space without conversion. 

Think of it like this: A colour space is very much like a unit of measurement. It's 30 yards (90 ft) between the bases in a baseball park. A yard is about the same as a metre (meter), so if you _convert_ 30 yards to metres the bases will be 27.4 metres apart. 30 yards and 27.4 metres represent the same distance, and a ball park with the bases 27.4 m apart will look the same as one with the bases 30 yds apart.

Now imagine the bases being 30 m apart. All that has happened is that the unit has changed, the value hasn't. Somebody has _assigned_ the unit to be metres instead of yards. The bases are further apart.

You could play around with this in Photoshop. Make a patch of perfectly even colour using the paintbrush, and sample it. Convert the image to another profile and sample again - you should see the numbers change but not the appearance of the colour. Now assign another profile. You should see the number stay the same, but the appearance will change. All this assumes that the colour you made in the first place is within the gamut of your display.

Does that make sense?

Best,
Helen


----------



## domromer (Mar 1, 2008)

It makes a lot of senses. Thank s Helen. So would it be smart to covert my workflow to adobe rgb then?


----------



## ann (Mar 1, 2008)

just to add another thought.

you probably won't see much difference on your monitor, but you will when printing unless as helen has already mentioned the vendor only prints in sRGB.

164


----------



## molsen (Mar 2, 2008)

honestly, almost everyone i talk to about this - pros, amateurs, printers - all recommend shooting in and using sRGB unless you're going to be doing your own printing.  it's simpler and you'll get the best results.

in my experience, this is true


----------



## Helen B (Mar 3, 2008)

molsen said:


> honestly, almost everyone i talk to about this - pros, amateurs, printers - all recommend shooting in and using sRGB unless you're going to be doing your own printing.  it's simpler and you'll get the best results.



It is definitely simpler, but shooting and working in Adobe RGB then converting to sRGB for output is simple enough. I recommend that digital photographers make an effort to understand and apply appropriate colour management.

If I want the best output I'm not going to use a printer who only uses sRGB. _That's throwing colours away._ Those of us who shoot film are often better off using even wider gamut colour spaces than Adobe RGB as our working space.

Inkjet printers have a wider gamut than sRGB. There are already many monitors that exceed the gamut of sRGB, and the number is bound to grow. Are you looking to the future? 

Here's what West Coast Imaging has to say in the Color Management section:

_"
[FONT=Verdana, Arial, Helvetica, sans-serif]*I               used to use a Lightjet and had to "convert" my files               to the Lightjet profile. Do I need to convert to your profile?*[/FONT]

[FONT=Verdana, Arial, Helvetica, sans-serif] No,               you do not need to convert your files when printing with us. Our               printing software automatically reads your workingspace profile,             then converts the data on-the-fly to the appropriate output profile,             before sending it to the output device. This lets you keep your files             in a wide-gamut workingspace, and easily repurpose them for other             applications. The software that powers most Lightjets is not capable             of doing this, which is why you had to  "convert" your             files.[/FONT]

             [FONT=Verdana, Arial, Helvetica, sans-serif]*What if my file is not tagged with a workingspace?*
              We                 recommend using RGB files for the best results. This conversion               will most likely cause a change in how the image looks, so it is               recommended that you convert to RGB yourself, so you can control             the process.[/FONT]
             [FONT=Verdana, Arial, Helvetica, sans-serif]RGB                 files that are not tagged with a working space will be printed                 as if they were sRGB files. [/FONT]
             [FONT=Verdana, Arial, Helvetica, sans-serif]... [/FONT]
             [FONT=Verdana, Arial, Helvetica, sans-serif]CMYK             files will be converted to Ektaspace PS5 and printed as-is. [/FONT]

             [FONT=Verdana, Arial, Helvetica, sans-serif]*My digital camera lets me use sRGB or AdobeRGB. Which should I               choose?*
              Most people find that they make better prints when capturing into               AdobeRGB."[/FONT]_


[FONT=Verdana, Arial, Helvetica, sans-serif]All good advice, as one would expect from WCI.[/FONT]


[FONT=Verdana, Arial, Helvetica, sans-serif]Best,[/FONT]
[FONT=Verdana, Arial, Helvetica, sans-serif]Helen
[/FONT]


----------



## ann (Mar 3, 2008)

ahmen, helen.


----------



## domromer (Mar 3, 2008)

Helen B said:


> It is definitely simpler, but shooting and working in Adobe RGB then converting to sRGB for output is simple enough. I recommend that digital photographers make an effort to understand and apply appropriate colour management.
> 
> If I want the best output I'm not going to use a printer who only uses sRGB. _That's throwing colours away._ Those of us who shoot film are often better off using even wider gamut colour spaces than Adobe RGB as our working space.
> 
> ...



Ok, I set my camera to adobe rgb, then I set cs3 to adobe rgb 1998, the last thing is lightroom. I have 2 choices there. I can do adobe rgb 1998, or pro photo rgb. When I tick pro photo it comes up with a message saying this is the recommend color space for preserving all colors in lightroom. 

SO can I mix pro photo rgb with adobe 1998 rgb, or should I keep everything the same at adobe rgb 1998?


----------



## Helen B (Mar 4, 2008)

domromer said:


> Ok, I set my camera to adobe rgb, then I set cs3 to adobe rgb 1998, the last thing is lightroom. I have 2 choices there. I can do adobe rgb 1998, or pro photo rgb. When I tick pro photo it comes up with a message saying this is the recommend color space for preserving all colors in lightroom.
> 
> SO can I mix pro photo rgb with adobe 1998 rgb, or should I keep everything the same at adobe rgb 1998?



The choice in Lightroom is for exporting images - the target profile, isn't it? (Has something changed?). Lightroom itself always uses its own space for editing*, then converts for output. Lightroom does its work in a space that has exactly the same gamut as ProPhoto RGB, though it isn't exactly the same as ProPhoto in other ways: it was designed to match the way Raw files represent colour information.

Exporting to a ProPhoto RGB image will, therefore, keep all the colours that were present in the original or generated in Lightroom. It is a very wide colour space, and is only worth using as an output space if you intend to do later processing (for example you are making a master file for later conversion for end-use) or send it to a real high-end printer. Because it is a very large colour space it is safer to use 16 bit colour than 8 bit. Trying to describe it with only 8 bits per channel can be dangerously coarse and lead to colour banding. Lightroom works in 16 bits internally.

Exporting to Adobe RGB _may_ lose some colours, but it is a good all-round colour space.

If you were going to export from Lightroom in ProPhoto, then it would make some sense to set ProPhoto as the working space in Photoshop, but only if you stick to 16 bit colour. 


*Lightroom reads the colour space of imported images that are tagged with a colour space, and assumes sRGB for untagged files then converts them to its internal colour space. Raw files have their own particular colour spaces (the native colour space of the sensor) that the raw converter must understand and convert to a standard colour space.

I hope that I have explained this clearly enough.

Best,
Helen


----------



## Tasmaster (Mar 4, 2008)

So, in very simple words, you are saying:

- Shoot Adobe RGB because it gives you more colours - a wider gamut.

- Convert to sRGB for the web and printing in case you have to print in sRGB.

Which means that you only need Adobe RGB (or any other wide colour space) if you are printing with a printer that supports, right?

Again trying to put it in simple words (correct me if i am wrong here):

Either shoot sRGB, pricess in sRGB, print in sRGB, or shoot Adobe RGB, pricess in Adobe RGB, print in Adobe RGB - the catch here being that your monitor can't display it but the prints will probably look better. If you have a monitor capable of displaying the full Adobe RGB gamut, i guess you are don't need simple word advice anyway .


----------



## Helen B (Mar 4, 2008)

Tasmaster said:


> So, in very simple words, you are saying:
> 
> - Shoot Adobe RGB because it gives you more colours - a wider gamut.
> 
> ...



...or if you may be printing with a printer that supports Adobe RGB in the future.



> Again trying to put it in simple words (correct me if i am wrong here):
> 
> Either shoot sRGB, pricess in sRGB, print in sRGB,...



That's fine, if you will never want anything better than sRGB. If you shoot Raw, and process in Lightroom your shooting and working colour spaces are decided for you. You only get to choose your output space.



> ... or shoot Adobe RGB, pricess in Adobe RGB, print in Adobe RGB - the catch here being that your monitor can't display it but the prints will probably look better.



I generally save the master files in Adobe RGB, then convert them to whatever is appropriate for output. That may be both sRGB for web display and Adobe RGB for sending to a printer (which will then have the printer profile applied).



> If you have a monitor capable of displaying the full Adobe RGB gamut, i guess you are don't need simple word advice anyway .



It's not unknown for people to buy digital photographic equipment that has capabilities that exceed their current requirements or knowledge. For example, do Mac users ever need simple advice about colour space, or do they automatically become knowledgable when they buy a Mac? 

Very few monitors display the full Adobe RGB gamut but many exceed sRGB and the number is likely to grow as people see the difference for themselves.

Personally I don't see the point in deliberately throwing away some of the capabilities of your camera, unless short-term simplicity is a major priority.

Best,
Helen


----------



## Digital Matt (Mar 4, 2008)

One thing that has not been pointed out is that Adobe RGB represents more closely the tones that can be printed in CYMK by a 4 color offset printer.  If you are intending to have any of your photos printed in brochures, fliers, or CD layouts for instance, Adobe RGB will give a smooth transition to CYMK.


----------



## Tasmaster (Mar 4, 2008)

Helen B said:


> I generally save the master files in Adobe RGB, then convert them to whatever is appropriate for output. That may be both sRGB for web display and Adobe RGB for sending to a printer (which will then have the printer profile applied).
> 
> [...]
> 
> Personally I don't see the point in deliberately throwing away some of the capabilities of your camera, unless short-term simplicity is a major priority.



The most sensible approach imho - thanks for the in-depth replies.


I still have issues with color profiles in the real world... for example why Firefox renders the same image very different in Adobe RGB than sRGB.


----------



## Helen B (Mar 4, 2008)

I was thinking about how to demonstrate the difference between a colour-managed browser and an unmanaged browser when I came across this excellent web page:

http://www.gballard.net/psd/go_live_page_profile/embeddedJPEGprofiles.html#

That page does include the statement: _"Further, sRGB workflow is the SAFEST COLOR SPACE to work in -- camera-and-scanner CAPTURE to monitor-and-printer PROOFING -- because sRGB closely resembles our monitor color space profile."_

Firefox 3 is colour managed, by the way. Firefox 2 isn't.

Best,
Helen


----------



## molsen (Mar 4, 2008)

this is why i said to use sRGB.  it simplifies EVERYTHING


----------



## domromer (Mar 4, 2008)

Ok here's another question. When I send a pic to the web without converting from rgb to srgb the pic will look muddy and dull, but when I convert a pic in PS to srgb from rgb, there is the slightest of difference. Why is that?


----------



## Helen B (Mar 4, 2008)

I guess that some of us don't value simplicity over quality and some do, though I think the comparison is between simple and even simpler.  Anyway, I think that there's enough information in this thread about the two approaches for readers to make their own minds up.

If you view an Adobe RGB image as if it was an sRGB image (ie the software ignores the profile tag) the colours will appear subdued because the Adobe RGB colour space is larger than the sRGB colour space. You are seeing the difference in the space. It's as if you drew a design on a balloon then let some of the air out - the balloon gets smaller and so does the design.

Converting from Adobe RGB to sRGB in Photoshop or any other colour managed application is like copying the design from a large balloon to a smaller one. The design will look about the same, but some bits might be missing or distorted where the design is larger than the small balloon.

Best,
Helen


----------



## Tasmaster (Mar 5, 2008)

After reading this thread again, and a two-hour chat with a color managed friend, everything is much clearer.

I wasn't aware of Firefox 3 either!


----------



## molsen (Mar 5, 2008)

i don't value simplicity over quality...i just don't see a quality benefit in using AdobeRGB.  all i see is a hassle and room for error.

i used AdobeRGB for a few months and decided, without a doubt, it offered me ZERO benefit in color quality or range.  everywhere I print uses sRGB.  everywhere I want to share my photos (other than my own monitor at the time) uses sRGB.  i can't see ANY benefit in using Adobe.

like i said before, unless you KNOW your printer is using AdobeRGB, sRGB is the way to go.

for 99% of photographers, sRGB does the job.  using Adobe just adds unnecessary complications, IMO.  also, converting from one colorspace to another can cause image degradation----afterall, it's a mathematical equation and requires rounding off of values

http://www.earthboundlight.com/phototips/srgb-versus-adobe-rgb-debate.html


----------



## Helen B (Mar 5, 2008)

That's a good article, thanks for posting it. It helps people make their own minds up rather than telling them what to do. We aren't in any disagreement here.

Here are some quotes from it:

_"So which is better? As with many things, the answer is, "it depends." You have to step back to ask "better for what?"

"Many online photo printers deal exclusively in sRGB since that is the lowest common denominator. I'm guessing they have judged that keeping things simple minimizes the customer service and support issues they have to deal with, lowering their costs. But that doesn't mean you have to let them dictate how you shoot. Just be sure to follow their rules and convert things accordingly before you send them images to print."_

All good advice.

The main reason for me to have my own inkjet printers is because I can produce higher quality work from them than I can get from all but the best (and most expensive) commercial printing services. For me it is a simplicity vs quality issue, and I think that my clients appreciate that.

Best,
Helen


----------



## lillyofthenile1 (Mar 9, 2008)

This Post is mostly for Helen's benefit.

Inkjets are great, but there is still one issue with them that has yet to be resolved.  From my reading on the subject that has to do with a little problem called out gassing.  

Just something to be aware of if you plan on displaying your prints behind glass for any length of time.  You'll have have to take the entire thing apart to clean the glass from time to time.

The problem seems to come into play whenever you are using an RC type paper, like gloss, luster, semi matte, matte.  Most people use higher end rag to print on to avoid this problem, but then the costs can get out of control.

Helen, you are dead on when in essence you say it's the best affordable solution.

Other than those issues they're great & easy to use.

Lilly


----------



## DanielSmith (Mar 25, 2008)

about color space, you may take a look at these articles.
http://www.acasystems.com/en/color-picker/faq-cmy-color.htm


----------

