So here is the final chapter in my Color Management series.  My approach from the beginning wasn’t really to teach how to do color management, but to help those that don’t understand it (which includes most of us that use it) to trust it enough to actually use it correctly.

As I mentioned in the first article, there are many Color Management Urban Legends floating around.  On the surface they all seem logical.  As a photographer, you have a choice.  You can believe these urban legends, and use them, or you can trust the science of color management even though you don’t fully understand why it works and use correct principles.  The choice is certainly yours to make, and unfortunately there isn’t any real way to “prove” to someone through a bunch of web  articles that they can trust it.  Anyway, here goes ...

Color Management Urban Legend (CMUL from now on) #1:  If your output is to a device or facility that requires sRGB or just for the web, you should just use sRGB as your working space in Photoshop.

As with most of CMUL’s, they sound logical and seem to make sense unless you understand the purpose and capability of a complete color managed workflow. When I hear this, my normal response is why?  There is nothing simpler about using sRGB, it’s not inherently better or easier .  As I’ve discussed, the choice of a working space doesn’t have much to do with your images final output choice, and using a better workspace doesn’t change the workflow or make processing the images more challenging. Instead what you are doing is constantly forcing your image into a “lowest common denominator” state, and instead of using color management correctly, you are just using an output profile as a working space to constantly clip and force your data into sRGB.  Using this logic, would you also use your printer’s profile as your working space?  That’s basically what you are doing when using sRGB as a working space because your lab requires sRGB files.  Instead, the process is just the same as when printing your own prints... wait until the last step, then output files as sRGB images to send on to the printer.

CMUL #2:  If your image is an sRGB jpeg, you should use sRGB as your working space.

OK, I’ll admit this is a tough one.  Once you’ve baked the information into a jpeg, most of the image data has been discarded.  There isn’t much you can do to the image without causing some serious issues.  Most likely it really doesn’t matter what space you are using in this case, because you’ve already severely restricted what you can do with image anyway by not having the RAW file.  I don’ think using a wider space will hurt, and I certainly wouldn’t change my default workflow to sRGB.  As long as you have Photoshop confirming color management mismatches, if you choose to use the imbedded space (sRGB) instead of the default working space (such as ProPhotoRGB) when you open the file, you effectively set the working space for just that image as sRGB.

CMUL #3:  The camera can’t capture anything outside of the AdobeRGB space, so there is no reason to use a wider space (such as ProPhotoRGB).

Another “logical” conclusion.  My question is how do you know your camera doesn’t capture things outside of the AdobeRGB space?  Most try to prove this by showing a camera profile mapped against AdobeRGB that was made by shooting a target in an artificial situation.  There is nothing wrong with using camera profiles, but unlike printers where we can send information that we know exceeds the printers capabilities and then map how the printer responds to that data, shooting a chart like this doesn’t do the same thing.  Even if it were true (which it isn’t) this assumes that you will never do anything in the RAW converter that might push that data outside of the AdobeRGB space.  The simple fact is most of the time it does.  I’m not sure there is a technique that can actually measure the maximum limit of a cameras sensor, but I do know you can’t do it by shooting a color target lit by a strobe.  More importantly, by the time the RAW data is processed and reaches Photoshop, very few images will fit inside the sRGB space, and most won’t fit inside the AdobeRGB space.

CMUL #4:  Your monitor can only display a space similar to sRGB ... you can’t see things in the wider spaces anyway.

This is a common argument lately ... if you can’t see a color on the screen, then how can you know what adjustments to make?  It is important to understand you aren’t seeing those colors on the screen anyway - you never view the actual colors of the image when editing it in Photoshop.  What you see is the colors of your image mapped through the monitor profile.  The color management system is trying to display the image as it was intended to be seen, not as it literally is.  It’s goal is to maintain the relationships of density, color and saturation to the other colors of the image within the confines of the current monitor so as to preserve the perception of the image.  It is more about how saturated is this yellow than the yellow next to it.  Perhaps that yellow isn’t as saturated as the one your printer can make ... no problem.  When it maps your image data into the printer space, it can take advantage of the ability of the printer to produce a more saturated yellow, and modify all of the other colors to maintain the same perception of the image.  True, side by side you may discover that the yellows of the print are more saturated, but the overall effect is still the same because the relationships have been maintained. (If anything, the print may be just better than the display).   One additional thought ... almost all LCD’s have colors that exceed the sRGB space.  By using sRGB you aren’t even achieving the maximum quality your monitor is displaying.  Here is my Apple 24” LED LCD screen compared to sRGB  ...

As you can see, the sRGB space (solid color) fits completely inside my monitors space (wireframe).  My monitor, even though it isn’t a wide gamut display, exceeds sRGB in every possible color.  Most monitors today exceed sRGB in quite a few places.  In reality the world would be much better off if sRGB passed into the history books, because there are not many devices left ... cameras, monitors, and printers ... that do not exceed sRGB in at least some colors.

CMUL #5:  ProPhotoRGB is so much bigger than your data it has to stretch the data and can cause banding in some transitional tones.

Another “logical” theory.  With this approach we decide to throw away some of our data even though it won’t fit into our container, rather than use a container that appears way too large.  If you’ve noticed on my site there are quite a few images of golf holes ... I guess it’s pretty obvious that I’m into golf.  I remember one time waiting in line at a driving range where you purchased tokens to insert into a machine.  The machine would dispense 3 different quantities of balls,  based on which of the 3 tokens you purchased.  There were only 2 sizes of baskets however, and I watched as a person in front of me decided to select the smaller basket, but then inserted the token for the middle quantity of balls, incorrectly guessing that it would be large enough.  Pretty soon golf balls were spilling out of the top.  When it comes to working spaces, theoretically it might be best if we could use a space that barely contained our data.  That’s pretty impractical however ... so either you have to lose some information or make sure it all fits in your space.

The idea of the space being “too large” has more to do with the bit depth we are working with.  If we are only working with an 8 bit file, we are limited to about 16 million colors.  In sRGB or AdobeRGB this won’t be a problem ... this many colors spread throughout the space will still be close enough together that we shouldn’t see any problems such as banding.  If we choose to use  8 bit data in ProPhotoRGB, we have to expand all of those colors to fill the new space.  Same amount of colors, spread farther apart.  Indeed they may be too far apart in some cases, resulting in visual issues.

However, if we move to 16 bit image data, we now have 281 trillion colors to work with to fill that space.  With this many colors, despite the bigger space, the colors themselves are actually closer together.   This means an image in 16bit ProPhotoRGB can render transitions every bit as well, and perhaps better than the image in 8 bit AdobeRGB. Bottom line, if you choose ProPhotoRGB as your working space, you should also be using 16bit image data.  If you are only using 8 bit image data, you should stay in AdobeRGB .  Should you use 16 bit data in AdobeRGB?  Won’t hurt anything, but not much point in it.  Why use 16bit data and then clip it into a small space anyway.

CMUL #6:  My printer is only an 8 bit device, so why work with 16 bits?

First, even though the printer, or printer driver can only handle 8 bit data, that doesn’t mean it’s gamut fits inside of AdobeRGB.  I’ve already shown that AdobeRGB will result in clipping colors that many of todays printers can actually print.  More importantly the main concept is to not restrict any data of your image  file until the final step .. output.  If you work in a small space using only 8 bits, you are constantly “clipping” the information as you work on it ... compressing information and altering other information.  It is better to not have these artificial restrictions limiting your editing.  Let the color management system do it’s job, and map the colors into the output space when the time comes. 

Enough urban legends ... for now.  There are plenty more, and I may add some to the end of this article, and even update it as I think of or see others. 

As a closing statement to this color management discussion, I offer one last thought to those that just don’t trust it.  Lightroom has proven that a fully managed workflow from 16bit/ProPhotoRGB conversions works.  Color Management, once you set it up right can be just that transparent ... it just works.  I have yet to see anyone complain that Lightrooms workflow is causing issues with the printed output.  Adobe engineers did not place options for sRGB or AdobeRGB workflow into Lightroom ... there is no need at all.  The same workflow can be used in Photoshop, and if you are seeking maximum image quality, using 16bit/proPhotoRGB in Photoshop is the way to go.