Re: solarplate images up on my website
An easier way for beginning solarplatists that I used to do:
If you just take any image and do a bitmap of input 600dpi output 600 dpi it
works fine. On my website in the Learning section under Solarplate there is
the orchid image, the abandoned car chair in the forest image, the kissing
chickens image, for instance, that are all done bitmapped. This is a
perfectly fine way to work low tech for busy images and the only way I
worked in solarplate while my 2200 was still alive. In those I did not do
the 80% bit. BUT that was black ink only on an Epson 2200 at 10 min UVBL
exposure time. AND it didn't have any appreciable uniform areas to show
those stupid spots. AND I was able to use Photowarehouse OHP to do those.
With the 2400 I can't do any of that. I also did a bitmap image on the 3000
on PWOHP and it worked fine but in the vacuum frame at school it sucked ink
from the neg onto the plate so the neg essentially could only be used once.
I guess that is no big deal.
The other low tech way I tried was the Boegh method of making your image and
applying the halftone diamond 65lpi 45degrees to the image set at 80%. That
worked, too.
One faculty just did a sharpie line drawing on tracing paper and used that
as a neg, again exposed UVBL 15 watt Edwards unit at 10 minutes.
I also noticed on my last plate that I had used a fine point orange sharpie
and written in the density of my colorized ink and even that little writing
printed in the plate so it is amazing the detail this process will do. I am
going to actually add a chapter on it to my Alternative Processes Condensed
book since it is a contact printing process, but I do fear that suggesting
an imagesetter screen will be a stupid thing to put in the book at this
stage in imagesetter history. So developing a workflow, Loris, like you
have is probably what will have to happen.
I just ordered the solarplate book that Keith recommended from Photoeye and
am awaiting my next shipment of (expensive) plates. This time I ordered
both solarplate and KM73s to see side by sides.
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
----- Original Message -----
From: "Loris Medici" <mail@loris.medici.name>
To: <alt-photo-process-l@usask.ca>
Sent: Friday, February 23, 2007 7:51 AM
Subject: RE: solarplate images up on my website
Hi Jon, thanks for the information...
I feel it's worth to try. BTW, another option *which will only work for
persons who use digital workflow, who can find a printshop that has
imagesetter and doesn't charge too much for negative printing*, can be:
Making negatives with the aquatint screen incorporated into them - so
they can be printed in just one exposure!?
I tried to make one by by resizing an image to desired output size
(7x10") @ 225dpi (1). (Let me describe why I use 225dpi: Since the final
negative will be 1800dpi, I need to use a screen resolution of 1800 / 16
= 112.5dpi in order to get all the 256 possible tones + I need to
multiply this intermediate figure with 2 in order to minimise sampling
artifacts. Therefore my source image's resolution should be 1800 / 16 x
2 = 225dpi.) Then I applied the following curve: (input-output pairs) 0%
- 0%, 50% - 50%, 100% - 80% (2). (What I do here is compressing the
tones so that maximum black becomes 80% in the positive.) And finally I
converted the grayscale image to bitmap (Input: 225dpi Output: 1800dpi
Method:Diffusion Dither). See the result below:
http://www.loris.medici.name/single_exposure_1800dpi.jpg
The left side is the bitmapped file sized to "Print Size", the right
side is the same file at 100% magnification. If the blacks are OK (= no
open bite) with this type of negative, the next step would be printing a
digital step tablet (exactly using the same settings / making the same
modifications) and designing a process adjustment curve for your
specific materials and working conditions...
Here in Istanbul imagesetter printing prices are quite low (less than $1
per 9x12" negative @ 3600dpi output resolution - using a 225lpi screen),
so I would be happy to print some small negatives with different
settings and send to few of you to let you try... But this will only
work for you *if you have access to an imagesetter for relatively cheap
fees*.
Regards,
Loris.
-----Original Message-----
From: Jon Lybrook [mailto:jon@terabear.com]
Sent: Thursday, February 22, 2007 7:31 PM
To: alt-photo-process-l@usask.ca
Subject: Re: solarplate images up on my website
Thanks Loris,
Sounds like this should work, but I don't know the details involved with
how an imagesetter works. Maybe someone else could comment. I know
they DO have expensive software to precisely generate screens...so there
must be a reason.
One time I tried printing out screens myself on Pictorico. Comparing
them to imagesetter output showed they are worlds apart. Under a lupe,
the inkjet output dots were much bleedier, fuzzy and imprecise.
Imagesetter output was crystalline. Maybe inkjet technology will
improve to this level someday, but it ain't there yet. We still need
some way to get good film output once all the imagesetters die off.
Keep in mind when talking with Copygraphics, there were two different
methods Peter Ellzy used to create my 1800 dpi screens two years ago.
One used a software called "Ice Fields" - some proprietary software that
created a stochastic image from a normal one. I didn't like the results
using that one as much as the one using the 'normal' approach --
whatever that may have been -- maybe Photoshop, but I don't believe it
was. I spoke with Duane, the owner of Copygraphics yesterday and made
him aware people are interested in the 1800 dpi screen I use and that,
among the files in my folder on their computers from several years ago,
the one NOT made using Ice Fields was the one I personally preferred and
was recommending to people. He seemed to understand my concerns and
said he'd dig more into my old data and verify what was going on. I'm
hoping they find my old files and that they are able to output them
without the striation problems reported earlier.
Keep in mind, some people have reported that 1200 dpi stochastic works
fine for them and I guess that level of output is problem-free at
Copygraphics...
Jon
Loris Medici wrote:
Dear Susan and Christina (and all),
Why can't you make your own 1800 dpi 80% stochastic screen file
yourself in Photoshop (*1), save it in .eps format and give it to a
printshop running an imagesetter (whether they have the special software
or not) to print it directly (without applying rasterization in their
RIP)?
Steps for (*1):
1. Create an empty image (Mode: grayscale, resolution = 225 dpi, size =
according to your need)
2. Fill it with the appropiate gray tone (20% Luminosity)
3. Change the mode to bitmap (Output: 1800dpi, Method: Diffusion Dither)
4. Save it to an .eps file (they should open it at 1800dpi, size exactly
the same is in step 1)
See:
http://www.loris.medici.name/susanv_1800dpi_screen.jpg
Don't you think that the generated pattern looks like original aquatint
pattern? This is a 8x10" file that I processed as listed above (original
pixel dimensions: 1800x2250, bitmap pixel dimensions: 14400x18000). Left
side the original tone, right side the stochastic pattern at 100%
magnification. When you scale the file on the right to "print size", the
tone is identical to the left side...
If that works somehow, you won't have to be extra careful - to not
damage the screen - when printing; you're going to have your file
printed again if your aquating screen gets damaged (somehow).
What do you think? Am I talking nonsense - or do you think this is worth
to try? (I can send you a sample negative if you like - here in
Istanbul, imagesetter printing fees are very very low...)
Regards,
Loris.
-----Original Message-----
From: Christina Z. Anderson [mailto:zphoto@montana.net]
Sent: Thursday, February 22, 2007 4:03 PM
To: alt-photo-process-l@usask.ca
Subject: Re: solarplate images up on my website
I second this, Susan,
Yesterday I called all around. No one has imagesetters anymore. One
place
has one up in northern Montana, but the other problem is the software
capable of doing stochastic is $50,000. He can do a stochastic right to
PLATE but not to film. But what do we do when the last imagesetter goes
out
of biz? I mean, would it be the same if we did a digital one and
projected/enlarged it onto film ourselves, I wonder...
Also, the notes I have on screens so far: 1800 dpi, 80% density; from
Ross
20 or 40 microns and that stochastic is 2 different diameter dot sizes
of
diamond shape. I don't even know what all this means, what a micron
is--I
assume the 20 micron is a finer dot...
I printed out Jon's entire website and keep referring to it. Especially
the
little jpg of the different exposures and dots--very helpful, Jon. Chris
----- Original Message -----
From: "SusanV" <susanvoss3@gmail.com>
To: <alt-photo-process-l@usask.ca>
Sent: Thursday, February 22, 2007 6:45 AM
Subject: Re: solarplate images up on my website
Dear gravure folks... I got an email last night from Copygraphics, and
they believe they have the problem with the stochastic screens sorted
out. Yay!
I have tried to find someone around here to make me one (a stochastic
screen), and came up empty. it seems that even long established
printing shops have gone digital. One place told me he gave his
imagesetter away a few months ago! (and those things are lot of $$$$$
) Another problem is that they aren't used to making stochastic
screens... that's a random dot pattern rendered by special software
that not all places even have available.
so... I highly advise getting a screen now from copygraphics and
taking good care of it.
susan
gravure blog http://susanvossgravures.blogspot.com
www.dalyvoss.com
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