Send Colorsync-users mailing list submissions to
email@hidden
To subscribe or unsubscribe via the World Wide Web, visit
http://lists.apple.com/mailman/listinfo/colorsync-users
or, via email, send a message with subject or body 'help' to
email@hidden
You can reach the person managing the list at
email@hidden
When replying, please edit your Subject line so it is more specific
than "Re: Contents of Colorsync-users digest..."
Today's Topics:
1. Camera Profiling (Lindsay Merritt)
2. Re: Camera Profiling (edmund ronald)
3. Re: Camera Profiling (Jos? ?ngel Bueno Garc?a)
4. Re: Camera Profiling (Ben Goren)
----------------------------------------------------------------------
Message: 1
Date: Thu, 29 Jul 2010 14:05:04 +1000
From: Lindsay Merritt <email@hidden>
Subject: Camera Profiling
To: email@hidden
Message-ID: <email@hidden>
Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes
Hi folks.
OK, I know the general opinion on camera profiles and their worth but
please, bear with me.
I have a new Canon 7D and I use the latest version of Capture One V5
to process my raw files. I love the output of C1, have used it for
many years and don't want to change.
The problem is, the skin-tones I get from the 7D are just awful when
processed in C1. The skin-tones could only be described as luminous
orange. I've satisfied myself that this is a C1 profile issue for this
camera. I did this by using a 24 patch ColorChecker card and by using
both the DNG profile editor and ColorChecker Passport for ACR. The
camera produces excellent results either with the standard profile or
my custom one in ACR.
We can shoot anything up to 15 portrait sessions a day in our studio
and I need speed and reliability, hence Capture One. I don't like
using ACR and LightRoom not only will nor launch on my brand new Mac
Pro, I don't like the interface and dislike the external database.
Trust me, Capture One and I are friends...
My camera room is painted grey so as not to add color casts. My
Elinchroms are gelled to match at 5250K as measured with my Minolta CT
meter. We use a WhiBal reference in the first frame of every shoot.
This is to allow as perfect a color rendition as possible with the
least effort required in post production. This system has worked
perfectly for years until now.
I decided to build a custom profile for the 7D. I'd done them before
when I photographed artworks with a Kodak DCS 760. The results were
outstanding (and published). This process required a linear gamma tiff
file. I can't remember the software I used to create the profile but I
think it was made by Profile City (now defunct).
I set the lighting to perfection and using a Kodak Grey Card,
established the exposure with the Histogram, one line dead in the
middle of the screen, double checked the exposure with Minolta Falsh
Meter 1V and it matched to the tenth of an f-stop. Lighting was even
(and proven so when later measured with the Eyedropper Tool in CS4).
I photographed both the GMB ColorChecker DC card and the GMB
ColorChecker SG card to see which would produce the best results.
At this point, this is where I ran into trouble. I believed that the
profile should have been created from a linear gamma, tiff file with
no embedded profile and ProfileMaker was telling me that the image was
too dark. It wanted a processed ProPhoto RGB tiff file. I installed
Canon Digital Photo Professional in the hope that this would help but
not only did I have to embed a proffile, the largest available was
Wide Gamut RGB.
When processed, obviously a tone curve gas been applied and the file
looked normal, and what ProfileMaker was expecting but I knew that the
result would not be satisfactory and was proven right. I checked the
gamut volume against the Capture One standard CanonEOS7d-Generic.icm
profile in ColorThink 3.0 Pro. I knew then I'd not succeeded but tried
the profile out anyway. No deal.
I have ColorEyes 20/20 and reinstalled that but if anyone has used
that, it gives you the name of an animal and you require the match-
phrase. I did that, received my match phrase and when I relaunched the
application the following day, my bloody animal had changed and the
match phrase no longer matched. Who knew?
I've e-mailed for another match-phrase with the new animal but have
not been answered. I'm sure they believe I'm attempting multiple
installs...
So finally, my question. What do I need to do here? I can't see that
using an exported Tiff file complete with an embedded profile and tone
curve applied can possibly allow me to build a profile worth a damn.
Am I missing something? Is there software that will build an accurate
profile from an untouched converted linear gamma TIFF file? What
software (if not ProfileMaker) would Capture One be using to build
*their* profiles?
I can't test ColorEyes 20/20 (no match phrase) but the manual leads me
to believe that I'm heading to the same dead end that ProfileMaker
took me.
I'd accept any advice, am happy to provide the raw files I took of the
test charts etc.
Anyone, please?
Cheers,
Lindsay Merritt M.Photog.
About Faces Photography
318 Princes Highway
Bulli. NSW.
Australia 2516
------------------------------
Message: 2
Date: Thu, 29 Jul 2010 08:33:21 +0200
From: edmund ronald <email@hidden>
Subject: Re: Camera Profiling
To: Lindsay Merritt <email@hidden>
Cc: "email@hidden"
<email@hidden>
Message-ID:
<email@hidden>
Content-Type: text/plain; charset=ISO-8859-1
there are three issues here:
1 why c1 is doing so badly?
2 running the profiling workflow
3 lighting and photographing the card.
My suggestion would be to get in touch with Coloreyes as they are a
good company, and have experience in walking people through the
profiling process.
Edmund
On Thursday, July 29, 2010, Lindsay Merritt <email@hidden>
wrote:
Hi folks.
OK, I know the general opinion on camera profiles and their worth
but please, bear with me.
I have a new Canon 7D and I use the latest version of Capture One
V5 to process my raw files. I love the output of C1, have used it
for many years and don't want to change.
The problem is, the skin-tones I get from the 7D are just awful
when processed in C1. The skin-tones could only be described as
luminous orange. I've satisfied myself that this is a C1 profile
issue for this camera. I did this by using a 24 patch ColorChecker
card and by using both the DNG profile editor and ColorChecker
Passport for ACR. The camera produces excellent results either with
the standard profile or my custom one in ACR.
We can shoot anything up to 15 portrait sessions a day in our
studio and I need speed and reliability, hence Capture One. I don't
like using ACR and LightRoom not only will nor launch on my brand
new Mac Pro, I don't like the interface and dislike the external
database. Trust me, Capture One and I are friends...
My camera room is painted grey so as not to add color casts. My
Elinchroms are gelled to match at 5250K as measured with my Minolta
CT meter. We use a WhiBal reference in the first frame of every
shoot. This is to allow as perfect a color rendition as possible
with the least effort required in post production. This system has
worked perfectly for years until now.
I decided to build a custom profile for the 7D. I'd done them
before when I photographed artworks with a Kodak DCS 760. The
results were outstanding (and published). This process required a
linear gamma tiff file. I can't remember the software I used to
create the profile but I think it was made by Profile City (now
defunct).
I set the lighting to perfection and using a Kodak Grey Card,
established the exposure with the Histogram, one line dead in the
middle of the screen, double checked the exposure with Minolta
Falsh Meter 1V and it matched to the tenth of an f-stop. Lighting
was even (and proven so when later measured with the Eyedropper
Tool in CS4).
I photographed both the GMB ColorChecker DC card and the GMB
ColorChecker SG card to see which would produce the best results.
At this point, this is where I ran into trouble. I believed that
the profile should have been created from a linear gamma, tiff file
with no embedded profile and ProfileMaker was telling me that the
image was too dark. It wanted a processed ProPhoto RGB tiff file. I
installed Canon Digital Photo Professional in the hope that this
would help but not only did I have to embed a proffile, the largest
available was Wide Gamut RGB.
When processed, obviously a tone curve gas been applied and the
file looked normal, and what ProfileMaker was expecting but I knew
that the result would not be satisfactory and was proven right. I
checked the gamut volume against the Capture One standard
CanonEOS7d-Generic.icm profile in ColorThink 3.0 Pro. I knew then
I'd not succeeded but tried the profile out anyway. No deal.
I have ColorEyes 20/20 and reinstalled that but if anyone has used
that, it gives you the name of an animal and you require the match-
phrase. I did that, received my match phrase and when I relaunched
the application the following day, my bloody animal had changed and
the match phrase no longer matched. Who knew?
I've e-mailed for another match-phrase with the new animal but have
not been answered. I'm sure they believe I'm attempting multiple
installs...
So finally, my question. What do I need to do here? I can't see
that using an exported Tiff file complete with an embedded profile
and tone curve applied can possibly allow me to build a profile
worth a damn.
Am I missing something? Is there software that will build an
accurate profile from an untouched converted linear gamma TIFF
file? What software (if not ProfileMaker) would Capture One be
using to build *their* profiles?
I can't test ColorEyes 20/20 (no match phrase) but the manual leads
me to believe that I'm heading to the same dead end that
ProfileMaker took me.
I'd accept any advice, am happy to provide the raw files I took of
the test charts etc.
Anyone, please?
Cheers,
Lindsay Merritt M.Photog.
About Faces Photography
318 Princes Highway
Bulli. NSW.
Australia 2516
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Colorsync-users mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden
------------------------------
Message: 3
Date: Thu, 29 Jul 2010 09:43:02 +0000
From: Jos? ?ngel Bueno Garc?a <email@hidden>
Subject: Re: Camera Profiling
To: Lindsay Merritt <email@hidden>
Cc: email@hidden
Message-ID:
<AANLkTi=EAX19HgV67jYfmZ2aJE+yT6JW=email@hidden>
Content-Type: text/plain; charset=ISO-8859-1
Hello Lindsay:
Due to sensor CFA maybe never will have good transition between
shadows and lights in skin tones.
The idea on create a good prifile for a fixed environment is OK, but
the Kodak Grey Chart is, for me, out of color management workflow
because the presence of in camera histogram and the lack of color
management asociated a this tool.
I only use Minolta Flash Meter IV only to ensure that flat art is
uniformly iluminated or the contrast of a scene due to press and
monitor limitations.
It is supposed that you shot WhiBal with the exposure sugested by
Minolta FM IV. I use the Robin Myers Digital Gray Card or Color
Checker Passport White Reference to make WB. With Nikon D90 have to
shot the reference as if it was medium gray as manufacturer advises.
And I think that is a good idea shot too a contrast card to make more
uniform the capture stage, as references are for, avoiding changes due
to subject/object reflection characteristics.
You are lucky if you can afford a Color Cheker SG, but in your
environment a Color Cheker Classic could be enought.
Once determined exposure (that you can change to get a prefered
histogram) and white balance I shot in NEF (my Pentax support DNG) and
convert with Adobe DNG Converter to DNG (in this step is possible to
give a more comprehensive name to the file) with the purpose of be
able to profile with DNG Profile Editor, ColorChecker Passport or
i1Match (Color Checker SG required). Starting with ProPhoto and Adobe
Photoshop softproof you can get the better of your output devices. And
a good alternative is ArgyllCMS based GaMapICC.
I have recently purchased Capture One 5 (not Pro, that mean can't make
softproof) and find extremely slow, but with a very good highligt
recovery, but testing Adobe Photoshop CS 5 I have found improvements
that take me back to the emotional aproach to old 2.0.
Don't mention your output devices, and again as good alternative to
i1Match you can calibrate and profile with ArgyllCMS based dispcalGUI.
Necessary to mention that need colorimeter or spectrometer (taking
about i1Display 2 and i1Pro) and propper environment in your
"lightroom".
PD: Somewhere there is a GUI for, again, ArgyllCMS to profile your
camera under XP. Sorry, still waiting for a full ArgyllCMS GUI for OS
X.
Salud
Jose Bueno
------------------------------
Message: 4
Date: Thu, 29 Jul 2010 08:00:09 -0700
From: Ben Goren <email@hidden>
Subject: Re: Camera Profiling
To: colorsync user list <email@hidden>
Message-ID: <email@hidden>
Content-Type: text/plain; charset=us-ascii
On 2010 Jul 28, at 9:05 PM, Lindsay Merritt wrote:
I decided to build a custom profile for the 7D.
Lindsay, I feel your pain. And so does anybody else who's tried to
get colorimetrically-correct results from a digital camera.
If you don't already have a spectrophotometer, start budgeting now
for an i1 Pro (or at least the Munki). It will become an
indispensable tool. More on that later.
The best workflow I've come across so far is to use well-controlled
lighting; to use a manually-linearized DNG profile with the RAW
conversion; and to use ArgyllCMS to build an ICC profile as well as
to convert the profile to the working space.
In just a little bit more detail:
I recently got a Sekonic meter. Out of the box it was pretty good,
but the incident and spot readings didn't quite match. The i1 has an
incident light measurement mode, and Argyll will report the
illuminance levels in lux when you use it that way. To convert from
lux to EV(ISO100):
EV = log2(lux / 2.5)
The Sekonic was a couple tenths of a stop off from the i1. Once I
adjusted the Sekonic to match the i1, the ambient and incident
readings on the i1 were a perfect match, and both matched the in-
camera meter.
Next, I photographed a ColorChecker with just strobe modeling
lights, set up in a copy-stand configuration. I adjusted the lights
until the meter registered an exact stop setting, to the 1/10th,
across the entire field. I set the camera to match the meter reading.
To get the perfect white balance, don't use the eyedropper. Instead,
crop the picture so just your white balance target is visible. Then,
use the exposure adjustment until the histogram is somewhere near
the middle (it doesn't need to be precise). Lastly, adjust the two
white balance sliders until the histogram is a single white peak. In
ACR, you'll probably need to type in the actual color temperature,
as the 50K intervals the slider and arrow keys work in aren't very
fine-grained. (Side note: DPP always shows the histogram of the
entire picture, not just the cropped portion. I emailed Chuck
Westfall asking him to ask The Powers That Be if they'd fix it, and
he said he'd pass on the request.)
A bit of a diversion here: for these purposes, Tyvek is the absolute
best white balance target you'll find, short of Spectralon (a
suitably-sized piece of which will set you back more than the camera
body). Tyvek has a near-perfect flat 99% reflectivity across the
entire spectrum. It's not quite as good as PTFE, but the difference
isn't something you can measure with photographic equipment.
(Spectralon is an almost-perfect non-specular reflector as well as
being 99.9% reflective across the visible spectrum, whereas Tyvek's
surface is somewhere between a matt and semi-gloss photographic
paper.) The best thing about Tyvek? It's dirt cheap. You can buy
Tyvek mailers at your local office supply store, and you probably
already have a Tyvek CD envelope laying around somewhere. If it's a
natural white plasticy paper with lots of fibrous detail, it's
probably Tyvek. If a Sharpie pen spreads like mad along those
fibers, it's almost certainly Tyvek. And if a plot from your
spectrophoto
meter shows a flat line a hair's breadth below 100% reflectivity,
then, congratulations, it really is Tyvek.
(Canon sells Tyvek in roll form for banner printing. But, before you
get too excited...the printable side is coated with the same FWA-
rich stuff they use for their generic matt paper. The back side,
however, is uncoated and shows no sign of fluorescence or other
adulteration. So, if you do banner prints, get a roll, use it for
its intended purpose, but also cut yourself a large blank sheet that
you spray mount, back-side-up, to some foamcore for your perfect
white balance target.)
Next, remove the crop, return the exposure to neutral, and set all
the other controls to their neutral (*not* default) position. In
particular, brightness and contrast need to be at 0, the tone curve
needs to be flat, and so on. Save these as your new defaults.
At this point, in ACR, if you use the Camera Faithful DNG profile,
you've got a not-miserable starting point for profiling, but we've
still got a long ways to go.
From here, I opened the profile in the DNG profile editor. Though I
used the chart feature to adjust the (2600K) color table, what I
was really interested in was the tone curve.
You want to start with a linear curve as the base curve, and then
adjust it until the six neutral patches have the same Lab values as
the ColorChecker. How to do this...is far from obvious. You'll need
to know the Lab values from your ColorChecker, of course. You can
find averaged values online, or you can measure your own
ColorChecker with your spectrophotometer. (I did mention it'd be
indispensable, no?) Unfortunately, the DNG editor doesn't give you a
readout of picture values, and this isn't something you can eyeball.
But...Mac OS X ships with a ``Digital Color Meter'' that will read
out in Lab values. It takes the RGB levels sent to the video card
and runs them through the monitor profile.
Be sure you have the DNG editor set to apply CameraRaw adjustments,
and then create a curve that gets the Digital Color Meter readout of
the patches to match. Set aside at least an entire afternoon to do
this...there's so much trial-and-error and frustration involved that
I can't offer any specifics other than that it *can* be done, and
that the simpler the curve the better. The end result should be very
smooth, and all the Lab values should match to within a couple L*
units. But be patient and persistent.
Next, you want to calibrate your flash meter. Adjust the flash heads
until the meter reads an exact stop. Take the shot, and see if the
N/ 5 patch on the ColorChecker matches what it should (using, of
course, your brand-new DNG profile and all settings at neutral). If
not, change the calibration on your flash meter appropriately, re-
measure and re-adjust the flash heads, lather, rinse, and repeat
until the flash meter is properly calibrated.
Then, use the shot of the ColorChecker lit with flash to create the
6500K color tables in the DNG profile you created earlier.
(I found the auto-adjustment of the color tables to only marginally
improve results, but it did improve them. My ColorChecker Passport
arrived yesterday, and I hope to get a chance to put it and its
software through its paces sometime today or tomorrow.)
Now, we *finally* get to the point of creating an ICC profile. Shoot
the best profiling chart you've got. (I'm actually in the process of
making my own, with dozens of paints -- artist's acrylics and paint
store both -- applied through a silkscreen.) Be sure to use the
exact same lighting conditions as you intend to use for real. Apply
your shiny new DNG profile, save it as a ProPhoto RGB TIFF, and run
it through Argyll to create a profile. (That last step will be non-
trivial, but it's well documented and the support on the mailing
list is fantastic.) (Oh -- and don't worry about the fact that it's
already tagged with ProPhoto. It's a lengthy explanation, but the
short version is that the profile it's tagged with is entirely
arbitrary, and that's just the best to avoid clipping in the RAW
converter. Argyll will take care of changing ``what it is'' to
``what it should be.'')
Finally(!), shoot whatever it is you were planning on photographing
in the first place, save it using the same workflow as you used to
create the image of the profiling chart, and use Argyll to convert
the image to your favorite working space. (You could simply assign
the camera profile in PhotoShop and let it convert it to the working
space, but Argyll does a better job. Especially if you do gamut
mapping and a device link profile, though that's somewhat slower.)
Obviously, once you've done all the preliminary work, the actual
production work can be automated. If your lighting never
(significantly) changes, you can reuse the same ICC profile for
forever. Batch process the RAW files to TIFFs, and Argyll was
designed from the start as something to be scripted.
Is this an insane process? Yes. But it gives the best results of any
I've found so far. Whether or not it's worth it is another
matter...but, based on your email, I'm pretty sure you'll decide
it's at least worth a try.
An almost-final note: the state of the art in fine art reproduction
is way beyond ICC profiles. Roy Burns at art-si.org is doing mind-
blowing stuff, including taking multiple shots through different
filters and using the result to create a spectrally-represented
(rather than RGB-represented) file. And he's not the only one
working on this kind of thing....
A really-final note: I've found this linearized DNG profile to give
me the best starting point for ``artistic'' photos as well as copy
work. Generally, I only have to make very subtle adjustments to the
black point or contrast to created the desired ``punch,'' and
everything else after that is dodge-and-burn. If I could nail the
lighting in the real world (obviously not possible with available
light in the field), I wouldn't even have to do that much. The built-
in profiles / curves / etc. have more ``punch'' out of the box, but
they also clobber details and destroy color fidelity, and you can't
get it back. It's much easier to start with something that's as
close to the actual scene as possible and then adjust it to your
specific tastes than it is to try to start from somebody else's
interpretation and to re-re-re-interpret it to your liking. At least
that way you get to be the one to decide which details to clobber
and which colors to alter.
Cheers,
b&
------------------------------
_______________________________________________
Colorsync-users mailing list
email@hidden
http://lists.apple.com/mailman/listinfo/colorsync-users
End of Colorsync-users Digest, Vol 7, Issue 174
***********************************************