[alt-photo] Re: New Platinum Prints

[Loris Medici]

I've used two different printers for making digital negatives; first was
Epson 1290 (which was a perfect printer for the purpose of making digital
negatives), second is HP 9180B. Both Epson at 2880 dpi and HP at 1200 dpi
printing resolution aren't able to resolve 1x1 pixel checkerboard pattern at
360 ppi file resolution, "on Pictorico OHP (or Agfa CopyJet/SelectJet)". (I
mean it isn't resolved "in the negative", let alone the print...) With both
you can resolve 1x1 pixel in one direction (horizontal or vertical,
depending your printing orientation) but not in both directions.

Cyanotype (and most probably pt/pd and other iron - iron/silver processes)
can resolve much much higher, I remember to being forced to print cyanotype
emulsion up, when I was using imagesetter negatives printed at 3600 dpi
hardware / 225 lpi screen resolution, because it was showing the dots (not
individual dots but 16x16 matrix dot aggregates at many percentages!)
irregularly depending on paper texture, mottling the print tones.

BTW, 7 lines per mm does give just enough definition; it's slightly under
the resolution limit of the naked eye "with a 20/20 acuity", "when viewing a
reasonably sized print from ideal viewing distance". (e.g. 11x14" image
size, 1.5' viewing distance...) More than this doesn't matter to casual
viewer, only to the print sniffer (w or w/o a loupe)... Of course, I reckon
you need something significantly better for small sized prints (4x5", 5x7",
8x10"), where in-camera negatives clearly show an advantage. OTOH, digital
negatives / digital capture is way more practical. (In terms of cost and
bulk to begin with...)

I know master printers who shoot LF but print using digital negatives,
because of the convenience:
- Many output sizes. (You're limited to the size of your in-camera negative
in the traditional way...)
- Many process choices. (In contrary, you have to tailor your in-camera
negatives to a specific process...)
- Better / easier manipulation possibilities (burn-dodge under strong UV
light with long exposure times isn't fun at all...), with much more control.
- Saving the original negative (image) from harm due handling / exposing to
strong UV light and what not. Digital negatives are dispensable...
- ...???

Regards,
Loris.


-----Original Message-----
From: alt-photo-process-list-bounces at lists.altphotolist.org On Behalf Of
Christina Anderson
Sent: Tuesday, April 13, 2010 6:58 AM
To: The alternative photographic processes mailing list
Subject: [alt-photo] Re: New Platinum Prints

Loris,
This is one case where "small is better" :)

I get a 1x1 pixel target with pt/pd and cyanotype--actually any process
where the solution sinks into the paper.  WIth gum I get a 2x2.

Christina Z. Anderson
christinaZanderson.com

On Apr 12, 2010, at 2:37 AM, Loris Medici wrote:

> ...
> I can see the dithering with cyanotype whereas I 
> can't see it with pop pd, and the pd prints aren't less sharp than 
> cyanotype prints at all... (Both will show 2x2 pixels checkerboard 
> pattern in 360ppi file resolution, which makes ~7 lines per mm print 
> resolution. This is the max I can get from my printer anyway.)
> 
> Regards,
> Loris.