New color chart for high quality profiling in captures

[Doug Gray]

Crosstalk is a term that doesn't exists in spanish, and the direct translation doesn't make sense, so excuse me if I still don't get the idea. Can you describe the issue precisely?

See this here on LuLa where I show some extremely large dEs in near whites depending on the surrounding colors. Fortunately, this problem doesn't occur in drum or transmission scanning. Camera/lens are subject to glare but this can be controlled and usually has a smaller effect.

https://forum.luminous-landscape.com/index.php?topic=124885.msg1049190#msg1049190

[Daverich]

Oh, really?
Ok, I see now it's Josh. Is he michael's brother?

Regards,

Josh is Michael’s son.

[Daverich]

No. 

Did you just get up on the wrong side of the bed or what?

[digitaldog]

Did you just get up on the wrong side of the bed or what?

Or what. Question answered. 

[Alexey.Danilchenko]

I think that you expect from a photographer to be a color scientist. Photographers usually don't want to dig very deep into the technical stuff, and certainly color management represents a nightmare for most of them.
So they like solutions that doesn't make their life even more complicated. As simple as that. :-)

You underestimate or do not understand photographers - inconsistency of the results is a nightmare and targets will give you precisely that in different lighting. Camera manufacturers, raw processing software vendors already use that approach to build pre-canned profiles for a set of lighting conditions. There are even commercially available solutions albeit not without their problems.

I didn't know about your project, but although it looks very interesting, I don't think a normal photographer would be interested in buy (if it could be bought), learn to use and use it.

"Normal" photographers in your definition would not waste time buying and shooting targets either. If and when they do, they then quite quickly become disillusioned in so called simplicity of this approach. Been there - done that and I am not even a pro(just a hobbyist).

Same reason because less than 0,001%? of photographers use advanced tools that can offer more sophisticated results or experimentation, but they are complicated to use, and/or there's few people out there using them, and there's few documentation. Tools like Rawdigger, Rawthrapee and many more.

Tools like RawDigger give people control and understanding not complications.

By the way: do you have information about how to use that and what were the results? Any colorimetric analysis?

How to use what and results of what? Spectral sensitivity curves for cameras? Yes I did took some - they were quite close to published scientifically measured ones. They also fairly easily validated by taking shots of the measured colours in measured light and comparing to calculated camera response using spectral sensitivity curves. I don't understand the question about colorimetric analysis- if that is about accuracy of the profiles built from the known spectral sensitivity then nothing really stops you to tune profile calculation to any set of target colours as accurately as you need (recalculating the profile is a matter of running a software not reshooting a target, a new target under a new light).

Please  don't misunderstand me, I didn't want to seem rude at all. What I was trying to say is that the solution of measuring every spectral curve of the camera sounds rather complicated even for most pro photographers. At least in my country.

Shooting targets correctly especially glossy ones is much more complicated that that.

[digitaldog]

Tools like RawDigger give people control and understanding not complications.

Yes, a far more useful tool than any target/profile exercise. At least the photographers I know and have worked with, understanding the basis of optimal exposure is far more important.
And going back to profiles and targets, it's pretty difficult for even novice photographers to have issues shooting a Macbeth 24 patch target and building a .DCP profile for a few illuminants. after which they produce subjectively preferable color moving a bunch of sliders (or picking a preset  , they've built). Yes, for those doing high end repro work, those who do want to start (or finish) with output referred color, a different group with differing needs.

[Doug Gray]

Yes, a far more useful tool than any target/profile exercise. At least the photographers I know and have worked with, understanding the basis of optimal exposure is far more important.
And going back to profiles and targets, it's pretty difficult for even novice photographers to have issues shooting a Macbeth 24 patch target and building a .DCP profile for a few illuminants. after which they produce subjectively preferable color moving a bunch of sliders (or picking a preset  , they've built). Yes, for those doing high end repro work, those who do want to start (or finish) with output referred color, a different group with differing needs.

Good summary, Andrew.

[Alexey.Danilchenko]

And going back to profiles and targets, it's pretty difficult for even novice photographers to have issues shooting a Macbeth 24 patch target and building a .DCP profile for a few illuminants.

Acceptable profiles - yes. High quality - not in my experience. I did managed to get somewhat better results with QPCards in the past shooting them outdoors in lighting I needed (had CC passport at that time as well for comparison) - though that was 5-6 years ago.

From my point of view, looking at how profiles are generated from all the targets (mathematically), these profiles will be tuned to accurately reproduce specific target colours and not anything else.

[Alan Goldhammer]

And going back to profiles and targets, it's pretty difficult for even novice photographers to have issues shooting a Macbeth 24 patch target and building a .DCP profile for a few illuminants. after which they produce subjectively preferable color moving a bunch of sliders (or picking a preset  , they've built). Yes, for those doing high end repro work, those who do want to start (or finish) with output referred color, a different group with differing needs.

I've been using the X-Rite Passport and software since it came out some years ago.  It does give a reasonable profile for the lighting condition that is used and certainly is easy to use.  Of course it's only a starting point in the editing process.  An artist friend wanted some repro work done for several paintings so that he could have some images for printing cards and flyers.  The Passport worked well in the natural light situation that was used to capture the images.  Colors were far closer in the Raw files using the profile than without. 

I have yet to compare the results with those created by the Lumaiver Profile Designer that Torger and his colleagues developed.

[elliot_n]

And going back to profiles and targets, it's pretty difficult for even novice photographers to have issues shooting a Macbeth 24 patch target and building a .DCP profile for a few illuminants. after which they produce subjectively preferable color moving a bunch of sliders (or picking a preset  , they've built).

I've dabbled with this, using the Macbeth 24 patch target with my Nikon D800, but in most situations I prefer the canned profiles in ACR.

[digitaldog]

From my point of view, looking at how profiles are generated from all the targets (mathematically), these profiles will be tuned to accurately reproduce specific target colours and not anything else.

Yes, 'more pleasing' is what I observe. Perhaps better with a different target. Nothing to do with color accuracy. My main point was:
Few photographers need anything else IF using a raw converter that supports .dcp profiles. It's easy to build them, you don't need more than a few, you are expected to move any of the sliders or WB controls to produce a subjectively pleasing rendering you desire. You don't need an expensive target that's difficult to capture.
In terms of this new chart, in terms of the majority of photographers who don't deal with repro or scientific capture, anything else is well described by the last, great Bruce Fraser:


"You can do all sorts of things that are fiendishly clever, then fall in love with them because they're fiendishly clever, while overlooking the fact that they take a great deal more work to obtain results that stupid people get in half the time. As someone who has created a lot of fiendishly clever but ultimately useless techniques in his day, I'd say this sounds like an example."

[hurodal]

See this here on LuLa where I show some extremely large dEs in near whites depending on the surrounding colors. Fortunately, this problem doesn't occur in drum or transmission scanning. Camera/lens are subject to glare but this can be controlled and usually has a smaller effect.

https://forum.luminous-landscape.com/index.php?topic=124885.msg1049190#msg1049190

ok, thanks. I think it's the same issue I saw in my V750. I minimized that issue by cleaning the glass from the inside. Getting acces to the inside was not as easy, but once done it was definitely a big improvement.

[hurodal]

Josh is Michael’s son.

Oh, thanks for the info.

[hurodal]

You underestimate or do not understand photographers - inconsistency of the results is a nightmare and targets will give you precisely that in different lighting. Camera manufacturers, raw processing software vendors already use that approach to build pre-canned profiles for a set of lighting conditions. There are even commercially available solutions albeit not without their problems.

I haven't said any statement like 'you don't understand' or the like to anyone. So, I'm asking myself, why are you stating that to me? How can you be so sure about what I do or don't understand?
I have been teaching around 3,000 people in the last 20 years. About 300 of them are professionals, and I'm in contact with many, so I think I know them a bit...

"Normal" photographers in your definition would not waste time buying and shooting targets either. If and when they do, they then quite quickly become disillusioned in so called simplicity of this approach. Been there - done that and I am not even a pro(just a hobbyist).

Totally agree. They are not my target.

Tools like RawDigger give people control and understanding not complications.

I'm not saying Rawdigger is not a good tool. It indeed is. But just as a reference, of all the pros I know, barely 2-3 know and use it. That's less than 1%.

How to use what and results of what?

Your tool, of course.

Spectral sensitivity curves for cameras? Yes I did took some - they were quite close to published scientifically measured ones. They also fairly easily validated by taking shots of the measured colours in measured light and comparing to calculated camera response using spectral sensitivity curves.

So, can I see anything published? Or a tutorial on how to build and use it?

I don't understand the question about colorimetric analysis- if that is about accuracy of the profiles built from the known spectral sensitivity then nothing really stops you to tune profile calculation to any set of target colours as accurately as you need (recalculating the profile is a matter of running a software not reshooting a target, a new target under a new light).
Shooting targets correctly especially glossy ones is much more complicated that that.

Ok, so you mean with your tool you get the spectral curves of the camera that allows you to calculate the colorimetric appearance of any target given it's reference file with spectral data and the spectral curves of the lighting, right?

[digitaldog]

Ok, so you mean with your tool you get the spectral curves of the camera that allows you to calculate the colorimetric appearance of any target given it's reference file with spectral data and the spectral curves of the lighting, right?

A primer for you:

http://dougkerr.net/Pumpkin/articles/Colorimetric_Characterization.pdf

From the fellow you may    have mistaken for Bruce Fraser:

Building a perfect ICC profile for a digital camera viewing real
world scenes is only possible if the spectral response curves of the
camera happen to be an exact linear combination of the human eye's
cone response curves.  Since there are no such cameras, perfect
digital camera profiles are impossible.

There are always going to be some objects that the camera "sees" to
be the same color, and the eye sees as different colors.  A profile
cannot undo this data loss.

Thomas Knoll.

But just as a reference, of all the pros I know, barely 2-3 know and use it. That's less than 1%.

That speaks more about those you consider well educated pro photographers than anything else. 

[hurodal]

Acceptable profiles - yes. High quality - not in my experience. I did managed to get somewhat better results with QPCards in the past shooting them outdoors in lighting I needed (had CC passport at that time as well for comparison) - though that was 5-6 years ago.

Totally agree. acceptable or pleasant profiles are a thing. accurate and high quality is a different thing.

From my point of view, looking at how profiles are generated from all the targets (mathematically), these profiles will be tuned to accurately reproduce specific target colours and not anything else.

There are big differences in the accuracy of a profile depending on the number of patches (and that has been analyzed in some studies), and depending on the patch distribution. You'll get better accuracy where the chart has many patches concentrated in a particular area of the color map.
The superchroma has been designed so all the patches are at about dE 5 from the closest patches, so the distribution is uniform. I've seen charts with more than dE 30 (even more than dE60) from one patch to the closest, and that produces big errors.

[hurodal]

That speaks more about those you consider well educated pro photographers than anything else. 

Are you calling all them stupid or ignorant?
Oh, I see, you're the master and all the rest are stupid or ignorants. I get it.

You probably didn't notice but this your latest post showed everyone here what kind of person you're.
And, please, stop replying me. you waste your time.
Haven't you noticed yet that I stopped replying you, as I previously said?

[digitaldog]

Are you calling all them stupid or ignorant?

Misinformed IF what you say about them is true. I have to wonder, without a tool like RawDigger, how they figure out how to expose for raw data.

You probably didn't notice but this your latest post showed everyone here what kind of person you're.

That's great news.

And, please, stop replying me. you waste your time.

Stop asking questions to the group OR learn to use the Ignore functions of this site.... 

Haven't you noticed yet that I stopped replying you, as I previously said?

That appears to be another misconception of yours, since obviously to nearly anyone reading here, you JUST replied to me.
It's getting difficult to take you seriously again.

[hurodal]

By the way, would you trust someone that talks about himself as a master in camera profiling and recommends the following procedure for a good camera profiling?

1- take a photo with a 'good deal of colors' in RAW.
2- Get an untagged file from it (but don't explain how to get it). Very important!
3- Open it in Ps, and don't color manage.
4- open color settings.
5- Start playing with the profiles in the drop-down list, to see if any produces colors that 'you like best'. Don't forget to calibrate and profile your monitor!
6- If none of those work, just pick custom and start playing with everything there: primaries, gamma, WP...
7- Save that Frankenstein profile and you're done!

Andrew Rodney.
Creating camera profiles with Ps

 

"Donde las dan las toman".

[digitaldog]

By the way, would you trust someone that talks about himself as a master in camera profiling and recommends the following procedure for a good camera profiling?

Don't ask stupid questions about processes you don't understand or who they are directed towards**. 
Don't lie to readers here stating you're going to ignore someone's posts and not reply, then reply two times within 10 minutes.
Don't post before and after pic's to sell a target whereby the pic's are bogus and don't represent what you're trying to SELL others.
Don't assume your arms are long enough to box with dog; they are not sir. 
Don't post another lie (I'd love to share and discuss technical details and the like with anyone interested here. I hope you find it interesting.), then decide what people have told you, isn't what you wanted them to say!


** EDIT: what you clearly don't understand and what you decided you needed to avoid posting and understanding was this important text outlined in the tutorial:
The following technique can be useful to people that have cameras whoʼs raw data is somewhat close to a standardized RGB Working Space. It can work for people who simply do not have the budget to buy special targets and camera profiling software or for those that are not happy with the results using profiling packages.