[BigMackCam]

I got hold of the ColorChecker Passport & accompanying software - not so much because I need absolutely accurate colour reproduction, but because I have a few camera / lens combinations now, and I wanted to be able to "normalise" the colour reproduction from them as much as possible.

Well, I've just done some very quick tests, creating a colour profile for the K3 + Tamron 28-75 f/2.8 here in the kitchen with overhead lighting. The results are really interesting. My display is calibrated using the ColorMunki Display tool, so I'm reasonably confident it is pretty accurate in the way it's displaying colours.

Here's what I've found:

When applying the new custom profile to the RAW capture of the Passport in Lightroom 6, the colours displayed on screen are a very accurate representation of what I see on the physical Passport. If there's a difference, it's not obvious to my eyes. That's given me confidence in both the ColorMunki Display calibration (which I've always felt gave a rather yellow-ish cast to the screen - but then, I know the original screen profile was heavily biassed towards blue), as well as the profile that the ColorChecker Passport software has produced.

When I apply the K3's Embedded profile, the colours are still good - better than I had expected, actually - but reds and blues seem darker, yellows less saturated, and greens ever-so-slightly lighter. Now, I don't know what lens they used when creating the Embedded profile, or the lighting conditions at the time - but I'm impressed it's as good as it is.

Lastly, when I apply the Adobe Standard profile provided in Lightroom, the reds and blues look lighter and significantly less saturated - weaker, overall - and the yellows just a little less saturated. Maybe a touch lighter on the greens?

Taking a photo of some soft drinks bottles with bright labels and tops (right behind where I stood the Passport when taking the profile shot), I again applied the different profiles. The new custom profile looked great - a very accurate representation, once again. The Embedded profile also looked good - just a little different in places (particularly the darker red and blue of the Pepsi label, and the yellow of another bottle's contents), without quite so much "pop" - very good, though. The Adobe Standard profile, however, left the photo looking quite lifeless - which ties in with my thoughts on a lot of the RAW captures I've been working on.

Of course, in this informal test, I had the benefit of creating a dedicated profile for the precise lighting conditions. In general use, I don't plan on doing that in every situation - instead, I'll probably create dual illuminant profiles for each of my camera / lens combos, starting with the most used. On that basis, I expect there will be some mild colour inaccuracies, but I'm confident I'll have a much better starting point going forward.

I'm left with three useful conclusions:

(1) The embedded profile is pretty trustworthy for general day-to-day photography, if not precise in its colour reproduction
(2) The Adobe Standard profile might be OK for some circumstances, depending on your camera and lens, but I won't be using it from now on!
(3) The ColorChecker Passport seems to work really well and is impressively accurate in normalising colours

To be fair to Adobe, their Standard profile can't possibly work well for every camera and lens, and it doesn't seem like a dreadful starting point - but we can do better!

Just thought I'd convey my findings in case anyone finds them useful

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Last edited by BigMackCam; 02-02-2016 at 11:13 AM.

[maxfield_photo]

The Adobe Standard profile is off quite a bit in the blues and purples, they are very desaturated compared to a Passport-generated profile. However, if you have Adobe Standard applied by default to your images (which my copy of LR does unless I tell it otherwise) a custom profile will look really off when you first apply it. It takes your brain a minute or two to reset it's white balance.

But out of curiosity, are you applying the Embedded profile in your images regularly, or just for comparison purposes here? I always use the Passport generated profiles. I generally try to shoot the Passport at every photoshoot, and then generate a working custom profile for those particular photos under those particular lighting conditions. When I go to edit my next shoot I do it again, overwriting the previous profile, this keeps the clutter down. Rarely do I ever re-edit my photos, but if I ever need to it's just a matter of re-generating the working profile from the calibration shot. I do keep Dual Illumination Profiles as a backup in case I forget to shoot the target, I do that for all my lens/body combinations, but I've never gone back to the Embedded profile. Just wondering if I'm missing something? (Like when I was double profiling my monitor in Photoshop for two years without knowing it.)

[BigMackCam]

The Adobe Standard profile is off quite a bit in the blues and purples, they are very desaturated compared to a Passport-generated profile. However, if you have Adobe Standard applied by default to your images (which my copy of LR does unless I tell it otherwise) a custom profile will look really off when you first apply it. It takes your brain a minute or two to reset it's white balance.

But out of curiosity, are you applying the Embedded profile in your images regularly, or just for comparison purposes here? I always use the Passport generated profiles. I generally try to shoot the Passport at every photoshoot, and then generate a working custom profile for those particular photos under those particular lighting conditions. When I go to edit my next shoot I do it again, overwriting the previous profile, this keeps the clutter down. Rarely do I ever re-edit my photos, but if I ever need to it's just a matter of re-generating the working profile from the calibration shot. I do keep Dual Illumination Profiles as a backup in case I forget to shoot the target, I do that for all my lens/body combinations, but I've never gone back to the Embedded profile. Just wondering if I'm missing something? (Like when I was double profiling my monitor in Photoshop for two years without knowing it.)

I've only recently started getting into the whole colour management thing. I started with display calibration about six months ago, after noticing that my photos generally seemed dark and colour-skewed when viewed on various devices. That was the first revelation - turns out my HP laptop screen's default ICC profile was way too bright and heavily biassed towards blue (strangely, my second monitor - also an HP - was close to spot-on colour-wise, though also too bright). Sorting that out with a ColorMunki Display tool helped enormously. But, up until the the last few weeks, I've not touched the Camera Calibration section in Lightroom 6, and I've been relying on the default "Adobe Standard" profile in my photos - hence I've had quite a bit of colour editing to do. It's only in the last few weeks that I started playing with the Embedded profile for my K3 photos, and they looked much better - but, without a custom profile to compare to, I had no way of knowing how accurate it was. Having now tried a couple of profile setups with the ColorChecker Passport, I can see that the Embedded profile is actually pretty good. The custom profiles are better, no doubt, but the Embedded profile is a more-than-decent starting point, and *way* better than Adobe Standard. I'm going to build Dual Illuminant profiles for each of my camera / lens combos in the coming days, and I'll probably use those rather than creating a custom profile for each shoot. If I was doing product photography, or other colour-critical work, I'd do the same as you - but this is just a hobby for me, so I'm happy with getting the colours "close enough" for now

[sTi]

If you really want to know more about camera profiling, you could do worse than read the documentation of DCamProf, a free camera profiling software (which also works with the Colorchecker)
Making a camera profile with DCamProf
DCamProf
It's very technical but extremely thorough.

To cut a long story short, none of the profiles you tried strives for absolute accuracy. This is due to technical limitations of the profiles (it is explained in more detail in the links above). What is more, different manufactures (Pentax, Adobe, X-Rite...) also apply a distinctive "look" to their profiles created with their software, so they are usually far from "neutral".

DCamProf is a command-line utility and quite intimidating at first. It took me a while to master it, but it's really worth it IMO. If you can wait a few days I can upload a K-3 profile created with DCamProf so you can compare. The killer feature of DCamProf is the so-called "neutral tone reproduction operator" it uses for the embedded tone curve: DCamProf

[BigMackCam]

If you really want to know more about camera profiling, you could do worse than read the documentation of DCamProf, a free camera profiling software (which also works with the Colorchecker)
Making a camera profile with DCamProf
DCamProf
It's very technical but extremely thorough.

To cut a long story short, none of the profiles you tried strives for absolute accuracy. This is due to technical limitations of the profiles (it is explained in more detail in the links above). What is more, different manufactures (Pentax, Adobe, X-Rite...) also apply a distinctive "look" to their profiles created with their software, so they are usually far from "neutral".

DCamProf is a command-line utility and quite intimidating at first. It took me a while to master it, but it's really worth it IMO. If you can wait a few days I can upload a K-3 profile created with DCamProf so you can compare. The killer feature of DCamProf is the so-called "neutral tone reproduction operator" it uses for the embedded tone curve: DCamProf

Thanks for the links, I'll look forward to reading the documentation! I'm happy to put time into this if it helps me to get a good, neutral baseline for colour reproduction.

[sTi]

I uploaded the profile for the K-3 and other cameras in a new thread: https://www.pentaxforums.com/forums/32-digital-processing-software-printing/3...ml#post3532064