Re: filmscanners: RE: filmscanners: Pixels per inch vs DPI

[Arthur Entlich <artistic@ampsc.com>]

SKID Photography wrote:

 > Art,
 > I'm not trying to be difficult, but  I don't understand what you are 
trying to say with the below post
 > relative to film grain.
 >
 > Are you saying that because inkjet printers employ a schoastic 
dithering pattern to represent pixels that film
 > grain and scan pixels (samples, whatever) are equivalent in regards 
to the amount of information they impart
 > to an inkjet printer?
 >


I wouldn't mind if you want to be difficult ;-)

But no, I'm, not saying that they are equivalent.  But I am saying that
inkjet printers get around the defined pixel array and rectangular
aspect of pixels (and their defined borders) by using a printing method
which randomizes the edges and placement of the dots (as much as by
1/2880th of an inch).

Therefore, some of the rigidity of the pixelized nature of digital
images is mitigated by the printing process used.  One could argue that
film isn't continuous tone either, since the size of the dye clouds are
random but relatively predetermined by the silver grain size, and they
also do not have a full variation of levels of color density.  It is the
random nature of the three different layers of the grain/dye clouds that
creates the analogue result which we find more pleasing, because, as you
stated, an array with rigid sized and shaped "steps" is more obvious to
our eye.

Unless one works hard at trying to create steplike diagonals, (for
instance), which certainly can be visible in a screen image at certain
magnifications, it is relatively hard to reproduce these in the inkjet
printed image, unless one works at very low resolution.

I both ran a color lab and did custom Cibachrome images using fairly
good Nikon EL lenses on a Beseler enlarger at home, so I have a fairly
good sense of what good prints look like.  Using a several year old
Epson 850 printer with there photo paper I've been producing 8x10s from
scanned 35mm slides, and I'd be hard pressed to pick them out from a
reasonable custom type "C" lab print.  Maybe not as good as a Ciba, but
fairly close.  Other knowledgeable people I show them to agree.  The
"secret" for me is to use 1440 dpi, the photo paper  setting and the
"microweave/super" printing feature to prevent banding, and error
diffusion, and make sure the heads have no clogged nozzles.   Sure, with
a loupe you'll see some dots (the printer uses down to 4 picolitre
dots), but that's smaller than most photo grain appears on a 8x10" print.


Art