Digital BW, The Print

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, Walker Blackwell <forums@...> wrote:
>
> What I'm really interested in is how ABW prints might shift color  
> between different papers/printer combos vs MIS and Piezography inks as  
> they fade under light. This is almost a larger concern than black fade  
> for me. As long as black fade is consistent and slopes off (ie: slows  
> down) on an even curve, I'm ok with it. But if different tones start  
> hueing out of control, then it's time to chuck that printer/ink/paper  
> combo out the window.

Right, which is why I* color is broken out from I* tone. I* color tracks hue and chroma retention while I* tone scores lightness and contrast retention. And it weights low chroma color (e.g monochrome prints) versus high chroma color whereas delta E has no such weighting function That means to interpret the seriousness of hue shifting in low chroma colors with delta E versus errors in more vivid colors contained in full color prints, one has to make "expert" judgements.  I* color takes care of it automatically. Color shifting will wreak havoc with I* color scores while lightness and contrast errors bring I* tone scores down. We don't get that level of interpretation by looking at delta E averages.

> For those sending color samples to Mark MG, maybe we should strive to  
> send top-quality (ie: Linearized with CreateICC) ABW and QTR prints as  
> well so we all can start to build a concrete dataset and be able to  
> make decisions based on that. It will tell us what combos to not focus  
> on and what combos to really strive to perfect. Silver Rag on K3 4800  
> looks really promising. I'm going to print Cone Color K3 on Silver Rag  
> to send to Mark so we can all see how the two inks compete.

 If initial print quality is not at least satisfactory, I reject the sample for testing. It has happened only once sp far ( I then worked with the member to correct the problem), but the essential goal is to get representative print samples into test, ones that reflect the basic initial quality potential of the process.
> 
> 
> There is such complexity in how inks are overlapped and so many  
> combinations of paper and ink out there; it's been such an impossible  
> idea that none of us have really thought we could ever know for sure  
> what system of color/bw ink mixtures was better.
> 
> But now there is at least a glimmer of future possibility . . .

Yes, the combinations and permutations are nearly endless, but the AaI&A digital print research program is dedicated to tackling this challenge.  I just need about 25 members for every test I run to break even on these tests, and I"m no where near this membership/sample ratio yet.
> 
> Mark, I have one suggestion. Maybe on the site you could put up a  
> request board where you request swatch prints from your users. For  
> example, I see a Lucia OEM / Harman FB AI test up. It would be useful  
> to see the Epson 4800 K3 OEM test along side it but maybe it won't  
> come until you request it of your users. eh?

I haven't said much about this on my site yet, but in a way I'm starting to coordinate this type of very fruitful activity already. For example, an AaI&A member upgraded to an Epson 7900 but also owns a 4800. He requested to submit samples of the new HDR inks on a couple of papers, and I took the opportunity to request that he use the same paper  to submit both 4800 prints and 7900 prints on same paper batches. Then, I coordinated these samples in my testing so that they are running side-by-side. From a "design of experiments" perspective scientists call this a paired comparison test. It reduces all other potential variables to a minimum.  Those samples are going to give us our first hard look at whether the new Epson HDR ink set is better, worse, or dead even in overall performance with the older K3 inkset. Epson claims exact same performance which seems a little hard to believe, but then again, the current industry test protocol is based only on a single "limiting" factor and has no way of checking the new orange and green ink behavior. The I* metric and the AaI&A test method has no such limiting issues. Now, to let members Know about behind-the-scenes studies like this I have more work to do, but one way is with the "Replicates/Compare to" section on the report description page. I will soon put a notation in this box cross-referencing these samples if I haven't done so already. If at such time the test show positive differences, this type of testing will be good discussion for the AaI&A annual report to members, etc. We can do more of these types of member coordinated studies...all it takes is time and money! The programatic infrastructure to carry out this type of research is to a large degree already in place.
> 
> Also, maybe it would be useful for those of us who end up using the  
> site to have a user-profile area where we share the printer/inks we  
> are using. This way we can see if, for example, a user has a 9900 and  
> another user has a 3880. We can then coordinate our chart printing to,  
> for example, all send you HPR QTR/ABW/Color swatches from our similar- 
> generation printers so that you can begin the tests at the same time  
> instead of waiting for someone randomly to come along with the  
> comparable printer/ink/paper combo swatch. This way, you can also  
> quickly see everyones swatch printing capabilities and make requests  
> easier.
> 
Yes, profile sharing, and other member intiatives could be dove-tailed into the AaI&A activities. It's all possible. But is takes real effort. No free lunch.

> I hope enough funding comes through for this grand adventure Mark MG.

 I have high hopes, but in this economy it has been a real struggle to work on a new venture. An end-user driven testing program was a fundamental goal when I founded AaI&A in 2007. I've made a lot of progress, but now it's time for the photographic and printmaking community to "speak now or forever hold it's peace" as the saying goes.

best,

Mark