Digital BW, The Print

Hey

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "koloshor" <wiz@n...> wrote:
> 
> I don't see any ink density variation on the 4000, or my 2200. Do you always print in 
unidirectional mode, and align the printer for the OHP or white film you're using?

I am a bit red-faced. Even before I saw your comment, I pretty conclusively discovered that 
my current problem is a non-ununiform light source for exposing the print - not a printer 
output density problem. I am using an enlatger with a cold-lite head for exposure. And it 
appears that I am getting a hot spot that led me to my bad conclusion. A new lite source is 
next.

That said - the hot spot explains my current problems using a "red" (cyan and magenta 
inks) negative. The corner to corner printer density variation that I observed a year ago 
using black ink (Pk) still looks real. I didn't own a densitometer at the time, but now that I 
do, I have been measuring everything that isn't nailed down. I still have one of the test 
prints that I did a year ago that I have just recently measured. It is a direct 2200 output of 
a complex gray scale pattern on Epson Premium Semi-Gloss. And the corner to corner 
density variation is as much as 0.08.

I am going to do some more testing, but my current conclusion remains that the Epson UC 
black ink is problematic. Mark Nelson in his Precision Digital Negative book states that 
that is the case. However, I don't think he provides any direct evidence to support that 
conclusion.



>  I'm using a reddish black. I do the mix in PhotoShop by going to "levels" and raising the 
lower red limot from 0 to 128 (for 50% red), or 96 (for 37% red). You can mix red and 
black pretty freely for Ilford (oe Kodak, for that matter) multigrade. Red has both magenta 
(blocks green) and yellow (blocks blue). 

I am quite pleased with the results I have been getting with a basically red (R=255, G=B=0 
at dmax) negative color. The way I achieve applying the red is to create a new layer, fill it 
with R=255 and then setting the layer mode to screen. 

On Kodak Polymax/Polycontrast paper I have no problem producing near-dmax while still 
maintaining near-paperwhite. And, as I said before, the required adjustment curve for 
liearization is much more gentle (easily and accurately produced with the 16 points 
available in PS-curves). That wasn't the case when I used black ink and gray scale 
negatives.

> 
> I'm one big step closer to a solution on the 4000.
> 
> The problem with the 4000 is that it has about 40 basic paper types, while the 2200 had  
6. So checking them all out is going to take some time.

Please keep us posted on your 4000 results.

Doug