Re: solarplate images up on my website

["Christina Z. Anderson" <zphoto@montana.net>]

Jon, I should have been more specific--no black ink used in the colorized 
neg, greyscale neg using all inks like you're talking about, below.  I am 
very interested in what you say about David Hoptman because I thought he was 
using color ink only...also, he is the one that uses a 2/3 (!) aquatint 
exposure to a 1/3 positive.  Dan Welden has an example of an image in his 
book that is done, for instance, with a 1mn45sec aquatint and a 10sec (!) 
positive exposure on p. 87.  That blows me away.  This is why I wonder about 
the question of image determining in part the choice of aquatint time.

I just love this list--to find other solarplatists willing to share their 
work in the trenches.
Chris
----- Original Message ----- 
From: "Jon Lybrook" <jon@terabear.com>
To: <alt-photo-process-l@usask.ca>
Sent: Friday, February 23, 2007 9:38 AM
Subject: Re: solarplate images up on my website


> Christina Z. Anderson wrote:
> > One last thing:  I found that using a colorized ink neg a la PDN vs a 
> > greyscale neg on the 2400 (all inks) produced better blacks.  Who knows 
> > why that is.
> > Chris
> I know David Hoptman uses greyscale 2880 dpi using all colored inks for 
> his inkjet transparencies very successfully since moving from imagesetter 
> transparencies to inkjet.  I don't.  I use black ink only currently.
>
> I did a test early on comparing the two approaches (greyscale using color 
> and greyscale using black ink only) and found the tones in the 
> color/greyscale one to be much less accurate with the polymer plate I was 
> using at the time (JetUSA I think was the brand).  The results were 
> extremely different, in fact. Kind of makes sense to me in this way: 
> These plates are clearly more and less sensitive to different colors, but 
> who, apart from the PDN users can tell us precisely what colors these are 
> (I know Chris can).
>
> If, when using all colors, a 30% grey contains, say, 9% red to create the 
> grey, and the polymer plate happens to be more sensitive to red, that 30% 
> grey is going to wind up being lighter than it would on the computer on 
> your poly plate.
> A pure PDN approach would inform the happy user what color most accurately 
> blocks light on their particular plate after the testing is done.  So it 
> would be as predictable as all black and possibly more controllable.
> I believe what I'm saying about greyscale/color transparencies is correct, 
> but I'm not a PDN expert user...
>
> Let me know what you think.
>
> Jon