One more before shutting down...
Harald, Thanks. I don't know where Joseph Holmes got the "reciprocity factor" as reported from 2 to 8 and probably averaging around 2.5.
Interesting, because I wrote about a "reciprocity factor of 2-4" years ago. As I recall, I got this directly from Henry Wilhelm at that time.
I think the important thing is that 200 Wilhelm years is probably significantly better than 100 Wilhelm years. Having an independent standard by which to compare the ink/paper combinations is the crucial thing.
Yes. Being able to make relative comparisons has always been the main benefit of WIR numbers, in my view. But the WIR standard or testing protocol is based on certain criteria, and those criteria, while covering a lot of ground, do not take some things into account.
By the way, by my calculation one year of exposure to light at 35,000 lux as Wilhelm does translates into about 155 Wilhelm years (factor of 2 there to account for the fact that his "years" assume 12 hours per day exposure of the prints to light, while the test presumably goes on 24 hours per day). Is this correct?
What WIR does is expose the samples to a continuous bombardment of light until a failure point is reached, and then it extrapolates that to a "reference display condition" of 450 lux for 12 hours per day, which ends up being "Wilhelm Years." 450 lux and 12 hours per day is the reference for Wilhelm, or the "average user" experience that everything is based on. Kodak uses 120 lux.
If so, I would certainly think Canon should have some pretty significant data by now. That's what has me "concerned".
Yes, this does seem a bit odd, doesn't it, especially in context with all the other printer models that WIR has posted results for. I have no concrete knowledge of why this is.
Any other info you have on the intricacies of testing that I am not familiar with would be appreciated.
All I can say is that ASTM (Mark Gottsegen and his Artists' Material subcommittee) has thrown its hat in the ring with a completely different approach -- see www.amien.org
to contact Mark. And there is another player, too, which I will comment on very soon (on my website: http://www.dpandi.com)
. Again, a very different approach. Things are about to get interesting for print permanence.