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More neutral than almost all other gray cards

Drew Strickland

New member
Hi Doug,

No, I don't think so (unless one has a Leica M8). The commercially available filters are not without drawbacks, and I don't think that they are all that much different from what the internal filtration already achieves. They are different, but it's on top of what's already provided, so the additional effect is minor. It is mainly a variable of unknown magnitude between camera brands/models, so it could be used to reduce the inter-model differences as long as it is stricter than the built-in solutions.

I think it is much better to have a good Raw converter that knows the specifics of the camera model, and optionally a profile with a bit of a skin-tone tweak (at the expense of accuracy) for a given type of lightsource (color temperature).

Skin tone will still change with the lightsource's color temperature, at a different rate than the White Balance does, due to its unbalanced reflection along the wavelengths.

Remember, (my) skin reflects much more Red than Blue:
SkinRemissionSpectrum.png


And here are the spectral compositions of several Standard illuminants (source www.brucelindbloom.com):
D40.png

D50.png

D65.png


As can be seen, the weight of Blue wavelengths is more significantly changed than the already high Reds. Part of that is covered by White Balancing, but the unbalanced skin reflectance leverages the differences.

For example:
at 400nm, skin reflectance 13%
at 700nm, skin reflectance 37%

That has the following effect with different iluminants, at the 2 extreme ends of the spectrum:
D40 at 400nm, 26% * 13% skin reflectance = 3.4%
D50 at 400nm, 50% * 13% skin reflectance = 6.5% (= +92% vs D40)
D65 at 400nm, 82% * 13% skin reflectance =10.7% (= +215% vs D40)

D40 at 700nm, 120% * 37% skin reflectance = 44.4%
D50 at 700nm, 92% * 37% skin reflectance = 34.0% (= -23.3% vs D40)
D65 at 700nm, 74% * 37% skin reflectance = 27.4% (= -38.3% vs D40)

(Near-)IR registers to all wavelengths, thus desaturating the colors to different degrees between camera brands/models. That makes it difficult to design a one-fix-fits-all solution. The need to tweak remains, unless one stays with one camera model.
Skin color functions as a leverage to the change in wavelength distribution. Differences in skin color are leveraged by different color temperatures (and White Balance).

Therefore, a generic WB change has a drastic effect on skin color and on all other colors, a skincolor tweak allows a more accurate overall result. But then, we already knew that.

Bart

Ok. So, assuming your calculations are correct and also assuming we can correctly map the variances from one camera body to another. It seems, we are still left with a massive task and an inconvenient workflow. We would need different profiles for each major skin type for each camera body ever made- and potentially for any hardware revisions during the production run. This cannot be automated, at least not easily. And, we would still need a neutral reference in our photographs.

My question then becomes this. Is the difference in quality worth the expense of cataloging and creating all of these profiles and any plugin that would probably be needed for proper operation? DXO had a similar, yet arguably simpler task in creating "offsets" for different lenses. Because the market for the product is such a niche application DXO had to expand the reach of their core application and still seem to need to charge $270 for their product.

So, my question is not a scientific one. But, rather one of ROI. Both for the potential producer of such a product, and for the potential purchaser of said proposed product.

1) Would you pay $300 to $400 for a tool like this when it first came out, or would just say forget that and use the curves dialogue.

2) Let's assume you are not Bart (our smart, but not always curt colleague :D don't forget I'm just the simpleton). Let's assume you are a relative newcomer to photography and you know a little about post processing, but not very much. However, you've been doing the digital thing long enough to know you need better skin tone. Would you be able to clearly see the difference between the results of this proposed somewhat expensive software tool and the need for a neutral gray card tool, and the results of this other less expensive "one click" tool?

Serious questions.
 

Drew Strickland

New member
Another serious question.

During the research and design phase considerable time was spent on locating a white that matches the specs or exceeds the specs of the babelcolor target that you and Andrew seem to believe represents the pinnacle of neutral wb tools.

Such a media was located, but not included in the product. Why? Because, despite the theoretical advantages of such a high luminance white area, our practical tests showed this ultra neutral white was very prone to clipping. Yes, people should ensure proper exposure, etc. It just didn't seem to add much value over the two neutral grays, and would've required extra time and expense to include.

The question is this, where do you find an appreciable advantage of the high luminance of the babelcolor over the whibal in practical terms? Stated another way, ignoring the improved response at the blue end what advantage do you perceive comes from the ultra high luminance value?
 
Ok. So, assuming your calculations are correct and also assuming we can correctly map the variances from one camera body to another. It seems, we are still left with a massive task and an inconvenient workflow. We would need different profiles for each major skin type for each camera body ever made- and potentially for any hardware revisions during the production run. This cannot be automated, at least not easily. And, we would still need a neutral reference in our photographs.

The majority of the task is in the Raw converter. Remember all the complaints about Adobe Camera Raw's poor rendition of Red with Canons? Hence the need to 'calibrate' the response, which also improves skincolor accuracy (leaving us with a potential tweak for more 'pleasant' skintone).

My question then becomes this. Is the difference in quality worth the expense of cataloging and creating all of these profiles and any plugin that would probably be needed for proper operation? DXO had a similar, yet arguably simpler task in creating "offsets" for different lenses. Because the market for the product is such a niche application DXO had to expand the reach of their core application and still seem to need to charge $270 for their product.

Raw converters cost money. If their camera profiles are good, or can be replaced by tweaked versions, everybody is happy because less work is needed after conversion.

So, my question is not a scientific one. But, rather one of ROI. Both for the potential producer of such a product, and for the potential purchaser of said proposed product.

1) Would you pay $300 to $400 for a tool like this when it first came out, or would just say forget that and use the curves dialogue.

2) Let's assume you are not Bart (our smart, but not always curt :D don't forget I'm just the simpleton). Let's assume you are a relative newcomer to photography and you know a little about post processing, but not very much. However, you've been doing the digital thing long enough to know you need better skin tone. Would you be able to clearly see the difference between the results of this proposed somewhat expensive software tool and the need for a neutral gray card tool, and the results of this other less expensive "one click" tool?

Serious questions?

I don't see the issue between the price of a Raw converter, we still need one and some come free with the camera, and an additional hardware tool to change the White Balance. The Raw converter comes with its built-in tools to change color, even to selectively change e.g. skin color.
The real question remains: Do we change all colors to get some in a more 'pleasing' state, or do we only change the specific ones we want to get in a more 'pleasing' state? So yes, we would see a difference between the approaches, but the price of a Raw converter is not the issue.

I still feel we shouldn't change the whole image if a specific color range is our target. You have a different opinion because you sell a hardware tool that changes the whole image. We live in a free world, so we can agree to disagree.

Bart
 
Last edited:
The question is this, where do you find an appreciable advantage of the high luminance of the babelcolor over the whibal in practical terms? Stated another way, ignoring the improved response at the blue end what advantage do you perceive comes from the ultra high luminance value?

Okay, a serious answer.

If we want a White Balance, why would we sample a Gray Balance? We might want it to avoid clipping, but we also need correct exposure, so why would it clip? The BabelColor target offers both, White balancing and non-clipping exposure determination. If the target clips in one of the Raw channels, one can be pretty sure that the WB is not accurate due to the wrong exposure level. This is more useful for studio or controlled lighting situations, and bracketed shots. Of course the virtually perfect color consistency of the BabelColor target also allows to get very accurate results under difficult lighting situations.

A general benefit for White Balancing with a White target is that there will be smaller deviations than when we attempt to convert grey measurements to white settings. When a WB target has a small deviation at, say, medium grey levels, then the deviation increases when we extrapolate to white. So there is a benefit to using lighter grays, or whites.

Example, a color in Lab coordinates like 50, 3, 0 becomes 100, 5.3, 0 when converted to white. A color like 95, 3, 0 becomes 100, 3.1, 0 so virtually unchanged. What you see is what you get, with a white target.

In the field, when the actual exposure level changes anyway, the slightly lower accuracy of a light grey is less important. An already very usable overall impression of WB is good enough.

Bart
 

Michael Tapes

OPF Administrator/Moderator
...and also assuming we can correctly map the variances from one camera body to another.

As I have stated previously, in my experience the difference between camera model instances (different bodies) is insignificant.

A general benefit for White Balancing with a White target is that there will be smaller deviations than when we attempt to convert grey measurements to white settings. When a WB target has a small deviation at, say, medium grey levels, then the deviation increases when we extrapolate to white. So there is a benefit to using lighter grays, or whites.

[snip]

In the field, when the actual exposure level changes anyway, the slightly lower accuracy of a light gray is less important. An already very usable overall impression of WB is good enough.

Bart

Bart,

With all due respect I believe you are incorrect. The WB reference is used within the raw converter to balance the RGB channels based on a reference of neutrality. White is not better than light gray, and risks the chance of blow-out as we all know. Dark gray is not optimal because there are less bits in the linear data to resolve the balancing of the 3 channels. Light gray is optimal in terms of resolution of the data, and of course neutrality is king. There is NO advantage to white, in fact it is a detriment.

Michael
 

Drew Strickland

New member
As I have stated previously, in my experience the difference between camera model instances (different bodies) is insignificant.

Ok.

So, we're still left with a "lot" of cameras (all the old and new models by Sony, Canon, Nikon, Sigma, etc.) and new ones coming out every month. This is not a job for a small outfit. I would suggest it would only make any sense if implemented by an existing raw converter company who find the minor marketing edge it might provide worth all the extra effort before the big guys rip off the idea. Are you listening Michael? Or, maybe Bibble or C1.

I still don't think it will work very well because you still have to manually select which skin tone type from inside the converter. You also still have to include a wb reference. Again, not a mass market product. Very small market, in fact.

Can someone make money with it. Sure. But at what cost and what time horizon. Getting people to change raw converters is extremely difficult for all but the bleeding edge consumers. You then have to compete with everything else the raw converters provide with regards to overall workflow and dam. Think just a standalone raw engine is gonna cut it? Just ask C1 how that expression bundle thing is working out for them. It might work best as a plugin for an existing product such as lightroom.

And again, in theory these localized edits provide what truly visible difference from the MAX approach?

I haven't seen any real world examples yet. I can envision a few scenarios where it might be noticeable, but very few. When people are the main subject of an image (the only scenario where we care about any of this) I submit it would be a very rare image where people notice.

Where neutrality is desired, you simply use that setting.

With all due respect I believe you are incorrect. The WB reference is used within the raw converter to balance the RGB channels based on a reference of neutrality. White is not better than light gray, and risks the chance of blow-out as we all know. Dark gray is not optimal because there are less bits in the linear data to resolve the balancing of the 3 channels. Light gray is optimal in terms of resolution of the data, and of course neutrality is king. There is NO advantage to white, in fact it is a detriment.

Michael

Our tests agree with Michael's statement.
 

Doug Kerr

Well-known member
Hi, Drew,

Michael Tapes said:
With all due respect I believe you are incorrect. [I'm not sure who is being addressed here - dak] The WB reference is used within the raw converter to balance the RGB channels based on a reference of neutrality. White is not better than light gray, and risks the chance of blow-out as we all know. Dark gray is not optimal because there are less bits in the linear data to resolve the balancing of the 3 channels. Light gray is optimal in terms of resolution of the data, and of course neutrality is king. There is NO advantage to white, in fact it is a detriment.

Our tests agree with Michael's statement.

Indeed, that is consistent with my understanding of what we should expect.

Best regards,

Doug
 

Doug Kerr

Well-known member
Hi, Drew,

Who won the doughnut? Was it creme filled?

Sadly, Asher has not advised me of the identity of the certified winner.

As to its livery, Carla will, when the time arrives, make a determination, so that the latest science as of that time can be taken into account. She says she will select a filling, and/or coating, that does not contain too much red, so its tone will be attractive. Or is it too little? Well, she'll figure that out.

My own preference is for glazed hexagonal doughnuts, but of course I am so impractical (they are best acquired from a Dallas supplier).

Best regards,

Doug
 

Drew Strickland

New member
She says she will select a filling, and/or coating, that does not contain too much red, so its tone will be attractive. Or is it too little? Well, she'll figure that out.
Best regards,

Doug[/QUOTE

I know you're just itching for me to post the actual lab numbers and spectral curves and explain my rationale behind each of the color choices.

Perhaps I will at some point. That's going to require some time to post, and I don't think it is going to provide you with any more satisfaction than you have right now. Plus, there's too many good ball games on right now. Think TT can get past OK State? Alabama just pulled it out over LSU. Perhaps you don't follow football?

Maybe I can put up some reference information sometime next week.

In the meantime Michael can give you the lab numbers and curves. He has a MAX and the tools.
 

Doug Kerr

Well-known member
Hi, Drew,

I know you're just itching for me to post the actual lab numbers and spectral curves and explain my rationale behind each of the color choices.

Well, I would find that interesting, certainly.

Perhaps I will at some point. That's going to require some time to post . . . .

I certainly understand. And I realize that there are many issues beyond just not having the time to do it. Only you know what is appropriate to disclose at each point in time.

. . .and I don't think it is going to provide you with any more satisfaction than you have right now.

Well, who knows.

Plus, there's too many good ball games on right now. Think TT can get past OK State? Alabama just pulled it out over LSU. Perhaps you don't follow football?

Well, actually I don't, but others in the family do, so there's a small awareness washing over me!

Maybe I can put up some reference information sometime next week.

Well, we're always glad to learn more about these things.

In the meantime Michael can give you the lab numbers and curves. He has a MAX and the tools.

Well, if he decided he wanted to.

Best regards,

Doug
 

Michael Tapes

OPF Administrator/Moderator
In the meantime Michael can give you the lab numbers and curves. He has a MAX and the tools.

Yup folks,

That's what I am going to do with my Sunday. After all:

  • I purchased a Color Parrot (which was nothing more than a preproduction idea, IMO)
  • Had to request 3 or 4 times to get the finalized ColorRight.
  • And now I have purchased a Max (which contradicts the marketing intent of the Color Parrot)

So after this $200+ investment, the maker asks me (and you all) to assist in his marketing while he watches the ball games (well he does have balls!)

I have watched this thread quite amused. I have seen some blatant errors, and on some I have commented. I can only surmise that there might just be some other technical inaccuracies on these many pages. But then again, I could be wrong.

Enjoy your Sunday.

Tag. You're it <g>

Best wishes..MT
 

Drew Strickland

New member
Yup folks,

That's what I am going to do with my Sunday. After all:

  • I purchased a Color Parrot (which was nothing more than a preproduction idea, IMO)
  • Had to request 3 or 4 times to get the finalized ColorRight.
  • And now I have purchased a Max (which contradicts the marketing intent of the Color Parrot)

So after this $200+ investment, the maker asks me (and you all) to assist in his marketing while he watches the ball games (well he does have balls!)

I have watched this thread quite amused. I have seen some blatant errors, and on some I have commented. I can only surmise that there might just be some other technical inaccuracies on these many pages. But then again, I could be wrong.

Enjoy your Sunday.

Tag. You're it <g>

Best wishes..MT

Funny! I'm with Michael.

All work and no play... well you know.

As for helping with marketing. Sorry. No. This thread is a huge waste of my time from a marketing perspective.

Well, unless I only wanted to market the thing to the bleeding edge of folks who pretty much aren't going to buy the tool anyway. Let's see, that's about .01% of the folks it should be marketed to.

I came in here originally just to set straight some of the I'm sure intentional baiting statements made by my friend Doug. I do enjoy the banter. But it serves only my narrow interest, not the interest of the other shareholders of ColorRight.

The only benefit I can imagine from a marketing standpoint is that it allows me to flush out some of the red herrings the technical folks might try to throw at the tool. But, still, only a very minor benefit. To build a marketing program on that would not be wise.

In the end, I just enjoy the challenge of a good back and forth. I guess I've got to get back to some more boring things on my agenda- like marketing. Thanks for the reminder, Michael.

I hope you all have a great week. It's been fun. Seriously. :)
 

Doug Kerr

Well-known member
Hi, Drew,

I came in here originally just to set straight some of the I'm sure intentional baiting statements made by my friend Doug.

"Baiting" is a bit pejorative for a process that resulted in me gaining insight into, and appreciation of, the value of your new approach. Sometimes to find out if there really are any fish in a murky pool, we need to use bait.

Perhaps when you were studying color science you didn't attend the session on "quit while you're ahead".

Best regards,

Doug
 
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