Digital BW, The Print

Ernst Dinkla <e.dinkla@...> wrote:
>
> ...
> It now looks like all the dyes types have issues with 
> color constancy in monochrome prints, more than black
> pigments have.

My observations are consistent with that.  Still, I'd say for many if not most uses, the dyes will still look better on high gloss media.

> LEDs and CFLs are not without spectral pikes. 

The dyes seem to do better with LEDs and carbon pigments seem to do better with the fluorescent lights.  

Most of the CFs here now carry an "energy star" label which requires a CRI of 80 or higher.  See http://www.energystar.gov/index.cfm?c=fixture_guide.pr_fixtures_guide_lightquality .  The problem fluorescent lights I ran into with the gallery are older style, with a 75 CRI.  So the extent of the problem I ran into may be much less applicable to most people.

> ... whether the black dye colorant spectral reflection is irregular.


I think that is a significant part of the problem.  There is a green/cyan bias to the black inks, the peak of which may be too close to a similar peak in the fluorescent light spectrum.

> You did not mention the paper you used. OBAs remain an issue ...

I tried a number of papers.  The lower the OBA amount, the less the problem but even on Museo the dyes shifted colors too badly.

The glossy print that finally looked good enough to hang next to the Eboni-6 prints was the MIS glossy carbon plus LM and LC on Museo.


> Better wait for Quantum Dot LEDs if efficient, full spectrum 
> lighting is needed. Till then halogens are best.
> 

A combination of government energy efficiency regulations and economics is forcing the issue here.  I think "hot wire" technology is out of the question.  The current LEDs appear to be better than the CFs already.  We will just have to watch our profiling to be sure we don't end up with reddish prints.

Paul
www.PaulRoark.com