Digital BW, The Print

Hello Scott,

>>Wilhelm uses a test standard of 450 Lux @ 12 hrs/day to represent 
>>a typical environment for displayed prints. What does 100 hours 
>>of sunlight mean in those terms? 

>Each hour in the direct sun is equel to, roughtly, 100,000 Lux. So, 
>your test was subject to about 10 million Lux.
>Museum lighting is roughly 50 Lux. If you displayed that test under 
>50 Lux for 10 hours a day, the test print would have been subjected 
>to almost 55 years worth of museum lighting.

Ahh, thank you, that's the kind of info I was hoping for.  


>However, I believe your test print was subjected to more than 10 
>million Lux due to your geographic location.

Any idea how much more?

Ok, let's stick with 10 mil for now to make it easy and compare with
W's test standard...

Museum @ 50 Lux for 10 hrs
--------------------------------
500 Lux/day -> 182,500 Lux/year
55 museum years


Home/Office @ 450 Lux for 12 hrs
----------------------------------
5400 Lux/day -> 1,971,000 Lux/year
5 Wilhelm years

Amazing that a typical home/office environment is that much brighter
(9x) than museum lighting, I never would have guessed that much. 
Anyway, W rates unprotected VFA/ABW at 112 years.  In museum lighting
that would be about 1200 years.

If my 100 hrs represents 5 W. years, then it would take about another
2200 hours to reach 112 W. years.  That certainly puts things into
perspective. (someone please correct me if my math is wrong).

We must remember that W's rating is based on a certain amount of
acceptable change.  So it doesn't mean that a print won't show any
changes until that point.  I'll continue my testing and will report
back when the image begins to show some changes.  As for OBA issues,
I'm wondering if there will be any further changes beyond the barely
noticeable amount we have at this point...

Any comments?  


Regards,
Clayton


Info on black and white digital printing at    
http://www.cjcom.net/digiprnarts.htm
I-Trak 2.1   http://www.cjcom.net/itrak.htm