Re: PT/PD and humidity redux

Mark,

Longer scale with more humidity is expected. You say the Dmax remained the
same, so did the extra range come in the form of three more steps in the
high values? Did you notice any veiling of the blackest values? Also, did
you notice an increase in printout--pre-development image formation? You
don't mention what equipment you humidified with, but two minutes of added
treatment in a 60% environment could have made for a really humid sheet.
Finally, you'll find different papers have different humidity reactions and
different 'ideal' humidity levels.---Carl

-- 
           Web site with picture galleries
           and workshop information
           http://www.carlweese.com
From: Ender100@aol.com
Reply-To: alt-photo-process-l@sask.usask.ca
Date: Tue, 02 Mar 2004 00:17:13 -0500 (EST)
To: alt-photo-process-l@sask.usask.ca
Subject: PT/PD and humidity redux
I had an interesting experience the other night‹but I won't go into that.
However, earlier that same day, I was printing PT/PD using the Na2
method/chart that Dick Arentz has on his website.   Using Palladium and his
Love Potion #5, Cranes Platinotype, pre-humidifying the paper as I usually
do, coating in 60% humidity with my trusty magic brush, air drying the
coated paper for about 20 minutes, then exposing on the Nuarc for the
standard printing time for that contrast mix, and wearing my lucky shorts
with a panorama of Moonlight Over Hernandez printed on them (I think I got
them at the MOPA gift shop)‹I got the density range on the Stouffer step
tablet as predicted for this contrast mix.
I did a second printing to verify something and for the hell of it, after
the coated paper had dried for 20 minutes, I gave it another shot of
humidity for 2 minutes just before printing.   The results were surprising
to me.   The tonal range stretched an additional log .35, or over a full
stop on the same Stouffer step tablet.   The DMax remained the same‹about
1.33 and I was still getting true paper white with no fog.
Has anyone else had this experience?   Did you smoke a cigarette afterwards?
Mark Nelson
PS: I have this cool futuristic stop watch I time everything with‹I keep it
hanging from a loop around my neck for easy access.   The other day I had to
mail something at the post office and I forgot to take it off.   When I got
to the desk, the postal clerk looked at me and then the stop watch and asked
"are you timing us?" hehehehe
PPS:   Is it "step tablet" or "steptablet".   Or "step wedge"? I know what a
"Step Wedgie" is.... but then we're back to talking about my lucky Ansel
Shorts again.