Re: For those who are interested in making digital negatives using pigmented inksets

Jeffrey Mathias wrote:

>
>The following link shows a simple way to measure the resolution of
>the paper. In this case, the paper is Crane's Cover-90. It seems
>to be able to resolve somewhere between 300 and 600 lpi. A 600 ppi
>negative should have enough resolution so as not to be detectable
>when using this paper. I would not recommend 360 ppi as this would
>not yet be beyond the resolving capability of this paper.
>

I have printed 1 Pixel, 2 Pixel, 3 Pixel and 4 Pixel grids on
Pictorico with the Epson 2000P, scaled for 150ppi, 360dpi, 480dpi,
600dpi, and 720dpi, using settings designed to give maximum
resolution. Based on analysis of the grids with a 15X loupe the
maximum resolution of this combination appears to be slightly greater
than about 300ppi, but definitely less than 360ppi.

I also tested the negative with Clearprint Vellum, which probably
gives about as much resolution as one can get with any Pt/Pd paper.
Here again the maximum resolution is slightly greater than 300ppi but
definitely less than 360ppi.

My conclusion from these tests is that there appears to be no
practical reason to work at a resolution of over 360ppi since the
theoretical maximum resolution is below this figure.

The resolution of the Epson 2000P is 1440/720dpi. Current generation
Epson pigmented printers are 2880/1440dpi, or even higher. It might
be possible to achieve higher resolution with these printers on
Pictorico, but even if so the paper of the print itself will still
limit resolution to around 360ppi or slightly less.

Sandy King
Received on Fri Jan 2 13:23:42 2004