Digital BW, The Print

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, Ernst Dinkla <e.dinkla@...> wrote:

> On 04/18/2012 04:48 PM, Paul wrote:

> CRI numbers are like Lab values for paper white, they tell very little
> about the spectral distribution and flatter manufacturer's specifications.

And yet despite known limitations, both CRI values and L*a*b* ratings (using
UV-included and UV excluded measurements) have great practical merit. I've never
seen an FL or other type of lamp with CRI rating under 90 that provides a better
color viewing environment than Full spectrum fluorescents with 90+ CRI ratings.
Similarly, the Lab data I provide on the AaI&A website for media white points,
especially the delta b* values which compare the difference between UV included
and UV-excluded b*), correlate very well with Ernst's database of spectral
plots on media white performance. Both reporting methods reveal high, medium,
low, or no OBA content levels, for example.

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