Henry Wilhelm is indeed an expert in the field. I have no quarrel with Henry's credentials, and I respect his technical knowledge greatly. I still consider Henry my friend.
The problem for modern print longevity testing is that densitometry, and the WIR 3.0 densitometric criteria set are both totally obsolete in today's modern digital world of multi-color channel printing. First, densitometers cannot accurately account for the spectral properties of many modern colorants. It's the whole metamerism issue only worse because even specifying the illuminant doesn't fix a densitometer's misreading of the colors. Second, the fading characteristics of modern systems can deviate dramatically from the visual fading pattern of traditional color photos for which the WIR 3.0 criteria set was empirically designed. Henry is keenly aware of these issues.
This technical challenge on how to measure print fading the way human observers notice it over time excited me as a researcher, and so I began collaborating with Henry in the late 1990s... It was blue sky research when we first started working on it. The industry simply didn't have a workable color and tonal accuracy equation to turn to as the market moved towards inkjet photo printing. Moving from densitometry to Delta E or dE2000 wasn't the answer, either, because dE doesn't track the critical visual parameter of image contrast nor does dE weight hue and chroma perception in complex scenes correctly.
The work product of our collaboration was the I* metric, a set of perceptually linear color and tonal accuracy equations using CIELAB as the underlying color model. It can objectively and fairly measure any color printing system, regardless of the color technology employed. The I* metric can even be used to evaluate paintings and other 2d works of art on paper as well. Although I invented the I* mathematics, our two respective companies (WIR and McCG, Inc) both funded the work, and Henry's moral support and general enthusiasm for the project really helped keep it on track. I will always be grateful for that.
By the end of 2004 I was confident that the I* math was working correctly and from first principles. It was not empirically derived by some focus group or committee. I'm very proud of the I* research, and I fully expected WIR to embrace the I* metric and begin phasing it into its operation in 2005, but for reasons still unknown to me to this day, it never happened.
Hence, I founded Aardenburg Imaging & Archives in 2007, and began using the I* metric myself. It's open source. Anyone can use it, and I really thought there might be some interest from the graphic arts industry as well. The I* metric can evaluate initial color and tonal accuracy between any two images or prints. They don't have to be faded Yet to this day, no other researchers have ever bothered to ask me about it. Go figure.
I look forward to one day testing the new HP Z9+ inkset using the I* metric and the Aardenburg testing protocol. That said, I think it's going to be while.
cheers,
Mark
http://www.aardenburg-imaging.com
I admire your integrity of adhering to your friendship with Mr. Wilhelm, while at the same time being able to discuss business ethical standards. After all you are both colleagues and you both worked together on the superior method of measurement (I*). Also, if I remember correctly, the reason the densitometric approach is still in use is because of all absurd things, that it was
Loooooong ago approved by the ISO standards committee and that I* has not been because of funding requirements and that research needed to be conducted in an academic setting in order to be approved by ISO?
So in many ways, even though Wilhelm is aware of and appreciates I*, he is in fact hamstrung by ISO standards and I* remains in limbo because of this dilema. This appears an awkward situation because there is no "officially accepted, approved" method by which to make pronouncements, when in fact, the entire densitometric process is so outdated as to be obsolete. It does not surprise me that companies leverage this reality to incorrectly inform their customers, and make outrageous claims on longevity in the face of the lack of updated or current standards that are "approved".
Marketing has ever been thus. And although Wilhelm knowingly participates in this "corporate illusion", there is little else he can do while at the same time staying in business. It all seems like a
CATCH 22 to me. Unfortunately, now,
ALL the companies have lost credibility, by allowing this chicanery to continue.
It is a shame that Aardenburg is caught in the middle of this, particularly in light of the ethical stance of not accepting funding from the big 3 corporations to conduct studies. While your ethics are laudable, it does nothing for Aardenburg's bottom line, which is additionally eroded by
slipping signifiers which prevail in the industry relating to the terms
longevity, archival, permanence, etc. Apparently, the market reality is beyond what "real" photographers can any more trust, and is also far beyond what we most all can now even stomach.
Business bottom line trumps photography party line as gradually not only our prints fade, but so does our standard as time marches on.
Eventually, who will become the arbiters of these standards when both Wilhelm and Aardenburg are no more?
Our viewpoints will become moot, yet the proof will be in the pudding and the eating thereof, when in a hundred years, two hundred years, which images, in fact, will retain the integrity being bragged about currently. There will be no disputes about which company made which claims, as probably current technology will be entirely obfuscated by advances.
All this being said, after being one the few lone voices in the wilderness for a very long time regarding Vivera inks and Z series printers, I am really glad I bought the last of my 4 Z Series printers, while I could, (with 5 year Care Pack) and hope to print the heck out of them while ink still remains available.
I don't care what they say about the new printers. The Z3200ps fits my kurmedgeonly style well.
Mark L