Colorspaces, Printing and Profiles?
Q. sRGB vs. Adobe RGB vs. ProPhoto RGB
I've seen the sRGB vs. Adobe RGB debate since I first got into digital photography.
Adobe RGB has a larger color gamut than sRGB, but photo labs want sRGB.
ProPhoto RGB has an even larger color gamut than Adobe RGB.
Adobe Camera RAW will let me process my RAW files to any of these 3 color spaces,
but my camera (Canon) only lets me choose between sRGB and Adobe RGB.
What color space setting do you use in your camera(s) and for your editing in
Photoshop, and why?
Part two. In short since I realize this is a huge subject, but a brief
overview of how you use this to get a print to match the screen?
In camera I use sRGB since the only thing that will be used for is the jpg proofs
that I will never open myself but the clients will, and the review screen on
the camera which is not colorspace aware.
In raw conversions I use ProPhoto or adobe RGB, always 16 bit and more
often if its an all inhouse production and post work we use ProPhoto, if it
may be outsourced prior to final retouching we use Adobe RGB since thats what
many graphic houses and retouchers are familiar with. ProPhoto offers
the larger space and since we are working on a master file and it makes very
little difference which we choose we work on what offers us the most latitude
Pro 16bit, before things leave they are often converted always flattened.
Most often for post work things will go in Adobe RGB, for graphics we
ask a design house what they prefer, for prepress we do our own CMYK conversions
and approvals are included.
All of the printers have smaller colorspaces than Adobe or ProPhoto, but they
may have a specific color that hits outside the smaller spaces so its best to
do all work on the largest file and colorspace and than convert down to smaller
spaces. If you do not do much offset prepress work its better to let the
prepress house do it. Sharpening as well! They do it for output
and its always better. Capture sharpening is not needed and does nothing
but make the viewer of the process feel better in between, and in fact may result
in degradation of captures detail through the artificial induction of sharpening
that served no purpose! If you can do it at the beginning you can still
do it at the end, but if you change your mind or went to far its too late unless
you want to start all over, what was the point? none. Sharpen last
after conversion to colorspace and all resizing is complete and you are going
to a specific output if possible.
Clients and anyone outside of prepress or retouching/graphics/design only
get sRGB as most often they do not know nor care about the difference and I
have seen them watch a disc of proofs not even on a uncalibrated monitor which
is normal, not on one that is not colorspace aware, but on a television dvd
player at home that reads and plays jpgs!!!!!! God I don't think they
can look any worse if I let my cat screw with them before I sent them out.
But thats not that unusual I have had many calls from people who were doing
or mentioned just that. They are only looking at proofs for a selection
so it really does not matter, but I hate the idea of what they are seeing and
thinking it looks like. Thats life, I get over it
So I make sure its in a space that most devices, the internet and browsers
are most comparable too and that seems close to sRGB.
But hey thats me, sometimes I think too much
Now how do you match a print to a screen?
You need to have both ends calibrated, so you have a monitor profile than a
printer profile which generates an Icc. profile for that printer/paper combination.
they drift and change over time or with chemical/ink changes but should be close
for a while.
Now the adobe or prorgb or even srgb being a nice and relatively big colorspace
is a good choice for most people to work and retouch and do all corrections
to as a master file. Save that file as that larger space as a master file.
Once your done with the file and ready to go off to a printer of any sort, that
printer should have an icc profile associated with it, ideally made from that
specific printer and paper not a generic one for all epsons with lustre so to
speak, but that generic is likely better than none at all.
You get that icc profile and in PS you can go to view proof setup and choose
that colorspace/profile (View >Proof Setup> custom >Select profile
here)
You are now seeing what that printer can and should print from the file as it
is interpretated into what your monitor can see based on your monitor conversion.
The ideal way (as best it can be considering the difference between reflective
and transmissive media) Is when selecting softproof options, (View
>Proof Setup> custom >) than select your icc profile, and select simulate
paper white. Do not look at the screen when doing that, it will only show
you how bad it is to not be backlit, try it without looking and it wont be as
dramatic a difference to you. This basically cuts the dynamic range down
and tries to simulate what the image woudl look like on actual paper.
Try it, see if you like it. I do not usually do it that way, but I am
use to this for a long time and know things will not be as punchy when not lit
from behind
You adjust what that looks like in the color space of the printer until it is
optimized for print. Than you need to save that file as a copy but first you
need to actually convert the file to that colorspace as so far it was just showing
you a proof of it. You go to convert to profile and convert to profile. Once
converted you have two options, you can save with no embedded profile attached,
which works for many of the printers who ignore profiles anyway, or you can
save with the embedded profile so that anyone who opens it will know what it
should look like.
raw has no information on color matrix or color space applied, its actually what is captured from the sensor and looks like crap, using a converter reads that info and allows you to choose what colorspace you want from the larger colorspace the raw has and at that time you also set the WB that was shot in or alter to create a tint if desired, and the contrast curve to make it simulate the look you want.
Only a preview jpg and if you shoot a jpg is defined.
So shooting raw is like shooting negative film of many types and you have the option to convert it as velvia, provia, astia, tri-x and adjust the color temp of the film, only you can keep choosing different ones. The jpg is like shooting a chrome you have to pick the film stock before hand, and can alter it with contrast color tone and WB in camera, but once set it cannot be expanded, only altered after the fact which is degrading. So think of raw like shooting many film stocks at once, and a raw converter like many different options in developing all in one.
Raw does not degrade.
A jpgs colorspace cannot be enlarged only reduced, converting a file that is set in sRGB to adobe does not gain anything. In raw it does.
A great video tutorial about raw and all about conversions and getting the most from raw is http://www.rawworkflow.com/products/DVD/index.html
raw workflow for you should be.
Shoot with a whibal! shoot the card in the shot as full size as you can and make that your custom WB. Shoot one for every change of lighting.
Gel as before, after shooting the whibal. Make sure after you shoot the whibal, you select the custom WB setting on the camera. On the 1ds there are several matrixes, none matter for anything but proofing if you are raw, so if you are shooting people the portrait is OK its red and magenta biased, natural normally looks blah, but none matter as a raw converter does all the wonders for you.
Now keep the whibal shot for reference in conversion in case you need it. Now the shots will be very accurate color, if you want to tint the shots in camera, the best way is referenced here.Tutorials_Gels_Filters_GoodColor.htm
nothing I am sure you don't know, but its a slightly different way to think it through, great for stills and HD video. I even do it on the red though not as important given its raw as well
I like ACR because of the colors and ease of use. I also highly recommend bibble as another great source of good conversions.
With ACR, the issue is batching, if you shoot limited for ads I convert in ACR one by one so I have full control over everything, if I had a catalog shoot I would use lightroom, since its the same colors and conversion but designed for a more efficient workflow for volume.
©Stephen Eastwood 2008 www.StephenEastwood.com www.StephenEastwood.com/bio www.StephenEastwood.com/tutorials