Color Profiling Guide for Adobe Camera Raw 3
by Eric Chan
October 14, 2005
Update (July 2008)
I wrote this article back in 2005, when Camera Raw's profiles were
built into the plug-in and could only be tweaked via the
Calibration sliders. As of July 29, 2008, there is now a much
easier way to create colorimetrically accurate profiles for Camera
Raw and Lightroom: the DNG
Profile Editor. Be sure to check out Tutorial
5 and Tutorial
6 of the documentation, which explains how to automate the
profiling process using a ColorChecker chart. Much easier and
faster than following the manual process outlined below! It's also
more accurate, since the DNG 1.2 profile format's lookup tables
means that all color patches can be optimized for simultaneously,
compared to the approach in this article, which only optimizes for
For the time being I've decided to leave the original text of this
I've been using Adobe Camera Raw (ACR) and Adobe Bridge for my RAW
conversion and workflow since Adobe Photoshop CS2 was released. While
these tools are excellent in many respects, I've never been completely
satisfied with ACR's color reproduction. Reds and yellows, in
particular, come out looking rather anemic. I've mostly ignored the
unsatisfactory color treatment, but recent excursions to photograph
fall foliage (in which reds and yellows feature prominently) made it
much harder to ignore. That's when I looked into the possibility of
tweaking ACR's color profiles.
Photographed with a Canon EOS 5D and 50 mm lens. The color of
the foliage surrounding the waterfall improved noticeably
I recently found an
article by Bruce Fraser that describes the process of modifying
ACR's built-in profiles.
Essentially, the process involves photographing the 24-square GretagMacbeth
ColorChecker Chart with a camera, then fiddling with color
calibration controls in ACR to attempt to match the image values
with known reference values.
A digital version of the ColorChecker created by Bruce Fraser.
I couldn't be more pleased with the results. I've made profiles for
the conditions under which I shoot the most often: cloudy bright
(about 6200 K) and indoor tungsten (about 2800 K). In both cases, I
found that ACR's rendering of warm tones (reds, yellows) improved
significantly. Improvements in other colors are less prominent, but
color balance is much better.
Toy example. Place your cursor over the image to see the
result after profiling.
The comparison above illustrate these improvements. I photographed
the original image with a Canon EOS 5D camera and a 50 mm lens. In
the raw converter ACR, I set the white balance using the gray WhiBal
cards seen in the left side of the images. I created the top image
using ACR's built-in profile and found that the red jacket was very
weak and lacked saturation, as did Tigger's face. Looking at the
original scene and comparing it to what I saw on my calibrated
monitor, I also noticed differences in the green pillow and the blue
jacket, though these differences were relatively minor. After
tweaking ACR's profile for the 5D using the procedure described below,
I created the image on the bottom and found that it was far more
accurate: the red jacket, blue jacket, green pillow, and orange Tigger
were nearly spot-on. (Yes, the jacket is really that red!) The images
you see above have been resized and converted to sRGB for web display.
Another advantage of going through this procedure is that my two
cameras (a Canon EOS 5D and a Canon EOS 1D Mark
II) now produce nearly identical results in color. No, not
an exact match, but definitely close enough for my needs.
The purpose of this web page is to describe exactly the steps I used
to perform the profile-tweaking in ACR; I've adapted Bruce Fraser's
approach a bit. If accurate color reproduction is important to
you (or if you have nothing else to do and feel that spending 10
minutes fiddling with calibration sliders in ACR sounds like fun),
keep reading. I hope you find this guide helpful!
Profiling: step by step
The following steps explain how to modify the profiles using ACR 3.x;
this version of Camera Raw is part of Photoshop CS 2. Note that this
is a practical guide with little explanation of the theory and the
principles. If you wish to learn more about color science and its
relevance to photography, I suggest visiting Bruce Fraser's
online articles and Bruce
Lindbloom's web site.
You will need a GretagMacbeth
ColorChecker Chart. This is a checkerboard containing 24 colored
squares with known spectral properties. (No, it does NOT suffice to
print out an image of the ColorChecker on your inkjet printer and use
Expose the ColorChecker under your desired
Be sure to expose in RAW mode.
Expose at a low ISO (e.g. 200).
- Avoid nearby colored objects (e.g. grass, painted
objects, etc.), because these may
leave a color cast on the chart.
- Avoid including shiny objects (or anything
else brighter than the white square) in the frame.
- Keep the
illumination on the ColorChecker as even as possible.
- Expose carefully to avoid clipping the white patch and
the dark patch. Use your camera's histogram to assist you.
Stop down the lens (e.g. f/11 or smaller aperture)
to minimize vignetting.
It's reasonable to avoid completely filling the frame with the
- Open this reference image (which uses the ProPhoto RGB color space)
in Photoshop. (This image is a digital version of the
ColorChecker, prepared by Bruce Fraser by averaging LAB values
for several physical ColorChecker charts and then converting the
resulting file to ProPhoto RGB.)
The reference image on your screen should appear similar to the image
below. (I converted this image to sRGB for the purposes of
displaying it on the web.)
- Copy the RAW image of your photographed ColorChecker to the computer
and open it in ACR.
- Use the crop and align tools in ACR to exclude everything else
except the 24 squares of the ColorChecker (i.e. eliminate all
background material). The purpose of this step is to make the
histogram accurately reflect the squares' tonal values. You may
want to zoom in after performing this step to make the
easier to see.
- Perform the following setup in ACR:
Choose "ProPhoto RGB" as the color space in ACR's workflow options.
- In the Adjust tab, set all values except white balance (color and
tint) to 0. That is, set the exposure, shadow, brightness,
contrast, and saturation sliders to 0.
- In the Detail tab, set sharpness to 0, luminance smoothing to 0,
color noise reduction to a small value (e.g. 5).
- Set all values in the Lens tab to 0.
- In the Curve tab, choose "Linear" from the Tone Curve
- Set all values in the Calibrate tab to 0.
- Look at the histogram and make sure that nothing is clipped,
i.e. no overexposure and no underexposure. You can
check the highlight and shadow warning boxex to make sure that the white square
is not overexposed and that the dark square is not underexposed. If overexposure or underexposure has
occurred, try another
exposure of the ColorChecker with your camera.
- Press S to get the sampler tool. Add "sampler points" to the middle
of each square in the bottow row (the gray patches). Also add
sampler points to the leftmost three patches in the third row (blue,
green, red patches). Sampler points are a great new feature in
- Set the white balance (use shift-click with the sampler tool, or
press "I" to get the white balance tool) using the patch in row
4, column 2 (i.e. the
gray patch to the right of the white square).
Move the sampler tool over the surface of that gray patch (R4C2),
keep an eye on the RGB readout values, and make sure that the RGB
values are fairly neutral. They should not be more than one level
apart (e.g. 189 190 190 is ok). If this is not the case, then
there are two likely scenarios.
you may need to enter a value manually into the Temperature box
(see the right-most red outlined region in the figure above).
Using the arrow keys moves the values in +50/-50 value increments.
You may need to fine-tune the values by entering something in
between (e.g. 2725 instead of 2700 or 2750).
Another possibility is that there is a color cast, mixed
illumination, or uneven illumination on the ColorChecker; in
this case, it's probably best to start over and be more careful with the
setup when photographing the ColorChecker.
- Go to the Curve tab. Look at the sampler points that you added for the six gray patches.
Ctrl-click on each one to add a corresponding point on the tone
curve. There should now be six interior points on the curve,
corresponding to the six gray patches.
- While keeping an eye on the six gray patch sampler values near the
top of the ACR window, adjust the six points on the tone curve so
that the sampler values match the gray patches' reference values:
241 190 145 104 67 37
The easiest way to do this is to use ACR's keyboard shortucts. Use ctrl-tab (or shift-ctrl-tab) to select
the next (or previous) control point, and use the
up/down arrow keys to adjust the tone values. Hold down the
shift-key to make increments of 10 instead of 1.
If the patches' RGB values aren't perfectly neutral, that's ok;
just match the green
- Go to the Calibrate tab and check the dark patch (bottom-right, R4C6). If it's significantly
non-neutral, adjust the Shadow Tint slider until it becomes
neutral. Move your cursor (sampler) over the dark patch; the
RGB values should not be more than 1 level apart (e.g. 37 37 38
- Now comes the tricky part: matching the blue, green, and red patches
(R3C1, R3C2, R3C3). While an exact match is unlikely (I've
never succeeded!), it's possible to get the color balance
right, and that's what matters.
Here is the iterative approach I used.
Start with the green patch and try to get the values to be
proportional to the reference values. The references values for
the green patch are (85, 123, 67). So, for instance, if the green
sampler in the target image has a green value of 118, then aim for
(82, 118, 64).
Here is a table of green values to try to match (for greens in
range 115 to 130):
|R ||G ||B|
|79 ||115 ||63|
|80 ||116 ||63|
|81 ||117 ||64|
|82 ||118 ||64|
|82 ||119 ||65|
|83 ||120 ||65|
|84 ||121 ||66|
|84 ||122 ||66|
|85 ||123 ||67|
|86 ||124 ||68|
|86 ||125 ||68|
|87 ||126 ||69|
|88 ||127 ||69|
|88 ||128 ||70|
|89 ||129 ||70|
|90 ||130 ||71|
Use the green saturation slider to adjust red and blue values
relative to the green value. Use the green hue slider to adjust
red and blue values relative to each other. Tweaking the hue
slider will sometimes cause the green saturation value to change
(e.g. from 118 to 117). That's ok. Just keep tweaking the hue
sliders until the green sampler shows values that match one of the
rows in the table above.
For my example, here is what I got:
Notice how my values for the green sampler (sampler 8) match
one of the row (the sixth row) in the table above. For your own target image,
the necessary green hue and saturation slider values may be entirely different
from mine, so don't simply enter the slider values from my example!
Next, switch to the blue patch and its sampler. Repeat the
process with the blue saturation and hue sliders. The reference
blue values are (59, 48, 126). The following is the blue table
for blues in the range of 95 to 135:
|R ||G ||B|
|44 ||36 ||95|
|45 ||37 ||96|
|45 ||37 ||97|
|46 ||37 ||98|
|46 ||38 ||99|
|47 ||38 ||100|
|47 ||38 ||101|
|48 ||39 ||102|
|48 ||39 ||103|
|49 ||40 ||104|
|49 ||40 ||105|
|50 ||40 ||106|
|50 ||41 ||107|
|51 ||41 ||108|
|51 ||42 ||109|
|52 ||42 ||110|
|52 ||42 ||111|
|52 ||43 ||112|
|53 ||43 ||113|
|53 ||43 ||114|
|54 ||44 ||115|
|54 ||44 ||116|
|55 ||45 ||117|
|55 ||45 ||118|
|56 ||45 ||119|
|56 ||46 ||120|
|57 ||46 ||121|
|57 ||46 ||122|
|58 ||47 ||123|
|58 ||47 ||124|
|59 ||48 ||125|
|59 ||48 ||126|
|59 ||48 ||127|
|60 ||49 ||128|
|60 ||49 ||129|
|61 ||50 ||130|
|61 ||50 ||131|
|62 ||50 ||132|
|62 ||51 ||133|
|63 ||51 ||134|
|63 ||51 ||135|
Again, tweak the sliders until the blue sampler's values match one
of the rows above.
Here is what I got in my case:
After this step, you'll probably find that the sampler values
for the green patch have changed and may not be balanced
properly. That's ok. Don't worry about this for now; we'll
come back to it later.
Repeat the process for the red patch and the red saturation and
hue sliders. The red patch's reference values are (122, 58, 46),
and the table is:
|R ||G ||B|
|115 ||55 ||43|
|116 ||55 ||44|
|117 ||56 ||44|
|118 ||56 ||44|
|119 ||57 ||45|
|120 ||57 ||45|
|121 ||58 ||46|
|122 ||58 ||46|
|123 ||58 ||46|
|124 ||59 ||47|
|125 ||59 ||47|
|126 ||60 ||48|
|127 ||60 ||48|
|128 ||61 ||48|
|129 ||61 ||49|
|130 ||62 ||49|
|131 ||62 ||49|
|132 ||63 ||50|
|133 ||63 ||50|
|134 ||64 ||51|
|135 ||64 ||51|
|136 ||65 ||51|
|137 ||65 ||52|
|138 ||66 ||52|
|139 ||66 ||52|
|140 ||67 ||53|
|141 ||67 ||53|
|142 ||68 ||54|
|143 ||68 ||54|
|144 ||68 ||54|
|145 ||69 ||55|
Here is what I got after tweaking the red hue and saturation sliders:
- This completes one round of color slider tweaking in the Calibrate
tab. As I mentioned above, the red sampler might now show a
balanced set of values, but the green and blue sampler
values are probably off. In my example above, you can see that this
is indeed the case. They shouldn't be off by too much, though.
By repeating the above three steps, we'll quickly converge on
a balanced set of red, green, and blue patches.
Fine-tune the sliders by repeating the above steps, starting with
green, then blue, then red.
In most cases you shouldn't need more than three or four
iterations. Once you become comfortable with how the hue and
saturation sliders work in the Calibrate tab, this iterative
process should only take a few minutes.
After two more iterations in my case, I converged to this:
Notice how each of the red, blue, and green samplers match rows
in the tables above. None of them match the reference chart
exactly, though the blue and green patches come very close. The
red values are a little high compared to the reference chart; oh
well, we tried.
- Save only the calibration settings
by going to the right-triangle pop-up menu and choosing "Save
settings subset ...".
In the dialog box that comes up, choose
"Calibration" from the Subset menu and click the "Save..."
Give the target .xmp file a descriptive name, such as
"Canon_5D_xxxxxx_profile_daylight_iso200.xmp", where "xxxxxx" is
the serial number (or some other identifier) of your camera.
(Having this identifier is handy in case you use two cameras of the same
Digital sensors usually have noticeably different responses under
daylight and tungsten illumination. If you shoot regularly under both
of these conditions, I recommend creating separate profiles for
daylight and tungsten illumination.
Here is an example of an image taken in daylight with the Canon
5D in daylight, before profiling. Place your cursor over the
image to see the result after profiling.
Was it worth the effort? I think so. Place your cursor over the image to see the
result after profiling.
Below you can see the reference chart (top
image) and the physical chart photographed under a tungsten bulb with my 5D (bottom image),
after profiling. I converted both of these images to sRGB.
Clearly there are some differences, most notably the light skin
patch (R1C2), the blue sky patch (R1C3), the foliage patch
(R1C4), and the bluish green patch (R1C6). Even so, this is a
pretty good "visual" match.
My Canon 5D and 1D Mark II digital bodies now produce nearly
identical color after I tweaked their profiles. Place your
cursor over the bottom image above to see the chart photographed
with my 1D Mark II, after profiling.