U of S | Mailing List Archive | alt-photo-process-l | Re: Epson R2400 inks density

Re: Epson R2400 inks density

Alberto - thank you so much for some real data! It's fascinating to see how
the pigments vary so much in their near-UV absorption, and also how steep
some of the curves are in that region around 370 nm - so how different alt
processes with even slightly different UV-wavelength sensitivities will
require quite different pigment mixes in colorised negatives - hence the
need to calibrate for each specific process and set of materials (my
dye-based Epson 1290 inks will of course be quite different again).

One interesting point is the not-unexpected curve for black ink - probably
means that a black-only negative will be usable for a wide range of printing
methods, while a colorised negative needs to be matched to the alt process
it will be used for.

Are there any strong opinions out there about black versus colorised
negatives? (I'll be surprised if there aren't....)

Best wishes


On 30/4/09 06:33, "Alberto Novo" <alt.list@albertonovo.it> wrote:

>> Okay, if I'm reading this right,  Clay's graphs show how UV  absorbence of
>> one narrow spectral region varies as the amount of ink  varies, in other
>> words the amount of ink is varied and the wavelength (s) measured is
>> constant.  Alberto's show how UV absorbence varies  across wavelengths,
>> holding the amount of ink constant. Yes?