RE: Beginner Density Questions & Digital Negs

 
Michael, I don't agree with you on the fact that the cited 1.9 density
range figure is referring to the reflective density of the print. In my
understanding the 1.9 figure refers to the density range of the
negative. And when one talks about density range this means the absolute
dmax of the negative should be even higher: For instance, if the
negative material's base + fog density is log 0.3, then the absolute
dmax of the negative should be 0.3 + 1.9 = 2.2 - that is for being able
to print a full tonal image by using the specific process (and/or
coating solution/emulsion mix) which requires a negative density range
of 1.9. IME, it is impossible to get a printed density range of 1.9 with
palladium - this is closer to what you can get from air dryed fiber
based glossy silver-gelatine paper! I can't get such a printed density
range even after coating my palladium prints with glossy polyurethane
wood finish... (which improves dmax by log 0.3 - 0.4 / over regular
uncoated prints).
 
On the other hand, with print-out palladium (ammonium iron(III) oxalate
sensitizer + Li2PdCl4 - that is Ziatype w/o any contrast agent) the
negative density range requirement is considerably higher than 1.9.
(This is probably true for develop-out palladium also...)
 
Regards,
Loris.
 
-----Original Message-----
From: Michael Koch-Schulte [mailto:mkochsch@shaw.ca]
Sent: 15 Mayıs 2006 Pazartesi 18:23
To: alt-photo-process-l@sask.usask.ca
Subject: Re: Beginner Density Questions & Digital Negs

Gu,
 
In this context the value of 1.9 is referring to the "reflective"
density. In practical terms a densitometer in reflective mode would
measure the darkest part of your print.
...
 
----- Original Message -----

From: G Guhan <mailto:guruguhan@hotmail.com> Gunaratnam
To: alt-photo-process-l@usask.ca
Sent: Sunday, May 14, 2006 12:54 PM
Subject: Beginner Density Questions & Digital Negs

...
 
I've got some beginner density questions, largely stemming from the
phrase "correct density". I'm trying to do digital negatives for pt/pd
on an R2400, MIS inks, Pictorico OHP. I've read Dan's book and all the
articles I can find on the net, in more than one of them a proper
density range is written (ex 1.9 for Palladium). So what is this? Is
this the measurment one wants in the blackest black on a negative/digi
step wedge when using a densitometer? And does this correct density,
then translate into the highest density "black" one can get in a pure
palladium print?
...
 
Received on 05/15/06-11:31:53 PM Z