Digital BW, The Print

> From: michael3442
> 
> I'm plugging away at learning BO printing with my 2200 w. 
> Eboni and am 
> experimenting with different papers to set the underlying 
> warmth/coolness of the prints. One thing I've noticed is how 
> dramatically the color of the paper appears to change with different 
> light sources (color temperatures). One "natural" toned paper 
> seemed to 
> turn nearly pure white when viewed under a daylight temp. bulb while 
> looking very creamy/yellow under soft white tungston (2700 degrees). 
> So, I guess I should determine what color temp. is considered a 
> standard for galleries displaying photographs. Is there a 
> standard for 
> galleries? Do they generally use quartz lighting? And, what sort of 
> light fixtures and setup do you use for evaluating your 
> prints? Thanks.

Printing BO avoids a lot of color problems--just try to get neutral prints
from color inks! Halogen bulbs tend to give the fewest problems with
metamerism, since they are truly broadband light sources. Some
phosphor-based lights come close, but I've seen some stunning color shifts
on fabrics under lights that claim to have a color rendering index north of
90, so I'll never trust phosphors.

Solux makes inexpensive halogens that have reasonably accurate color
temperature, and you can get pretty cheap fixtures for them at any lighting
store. However, be aware that the cheap Chinese fixtures are designed for
125VAC, so if you use them in the US, they'll run a little cool, and the
color temp will be a tad low. This isn't a huge problem, but if you're
really trying to dial in an exact color temp (measured with a spectro at
table level), you can go to an elecetronics supply store and buy a variable
transformer that can convert 115VAC into 0 to 130VAC, and run everything
through that.

-- 

Ciao,               Paul D. DeRocco
Paul                mailto:pderocco@...