Digital BW, The Print

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, David Kachel <david@...> wrote:

> Where can I find information on how to read this?

There's a lot of supporting information on the AaI&A website. Most of it free to the public. That said, I know I have to do much better in bringing all AaI&A members up to speed on all aspect of the reports. I do tend to view this situation much like any task of higher learning. Start with some basics, take a deep breath, and add to your level of knowledge as you go. My job is to serve as your guide, but first I had to set up the testing infrastructure and get some data into play. That task is well in hand now, so I will turn my attention to more tutorials this year.

 Many of my members already understand CIELAB and the color difference numbers, i.e.,  those delta E values  and L*, a*, and b* values that are posted in my reports. But the I* metric is superior and it is designed to make it all even easier. Read the I* scores for average overall response and also the weakest 10% of the colors just like you'd read a grade point average. 90% and above is excellent tone and color retention, 80% good, 70% satisfactory, 60% poor. 100% is a perfect match and hence a perfect score. AaI&A also gives a "Conservation Display Rating" which is the range of megalux hours that the product can be exposed to and still show little or no noticeable fade. Paul has not given you those ratings, and indeed some of the samples in test and posted here aren't even at their rating limit yet, so the tests are ongoing. But the cool thing about the data is that, like Paul, you can directly and fairly compare the scores at fixed exposure levels. Paul has showed you the 30 megalux hour data which is equivalent to 15 WIR display years and about 60 Kodak years based on these companies' choice of "standardized" light levels in the real world. I believe there is way too much variability in the real world to choose just one "standardized" level, so I prefer to provide a table in the AaI&A reports and let people estimate their own display times based on the megaluix hour ratings and reasonable knowledge of the lighting levels in their chosen environments.

Some other points I'd like to make:

1). All the data Paul posted is true B&W mode printing except the HP Vivera sample. That's a color print, so the 50% midtone is indeed a gray, but the summary scores are for the system as it makes color prints. The scores would improve, I believe, if we run a true monochrome print test, because the HP photo grays are more stable than some of the pure colors, but I haven't recieved any B&W samples yet to test for the HP Vivera pigmented inks.

2). I'm pretty liberal about members sharing the AaI&A data, in terms of sharing with clients or using in educational settings. But posting of the AaI&A data to websites violates the AaI&A copyright without written permission to do so from AaI&A. Paul has my permission, and I thank him for his willingness to help me spread the word about the AaI&A research. Thank you, Paul.

3). Someone in the thread asked about the settings related to these test results and noted limited value without more information on the settings used to make the prints. Quite right, and the AaI&A test reports go to great length to document those settings. I rely on members providing this information to me when the samples are submitted, and more and more, I'm requesting screen shots of the driver menu settings, and AaI&A members are for the most part more than willing to provide. So, for example, if you download the Epson ABW sample that Paul excerpted, the description page shows the ABW settings used to make the print in a screen shot. Incidentally, the submitting member worked hard to match it to the Cone Carbon Sepia color, and it's remarkably close in terms of initial hue and chroma for both systems.

I hope my comments help without sounding overly self-serving.  I know it takes time to digest this research and that my job is just as much to educate my audience as it is to  collect the test results. I'm working on that. I ask for a little patience.... and more members to help me continue this research. The results to date fascinate even me (I've been doing this type of testing for a couple of decades), and as a fellow printmaker, I'm still learning a lot, too!

thanks,

Mark
http://www.aardenburg-imaging.com