Digital BW, The Print

----- Original Message -----
From: "Anthony Atkielski" <atkielski@...>
To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
Sent: Sunday, August 04, 2002 12:15 AM
Subject: Re: [Digital BW] Number of tones was Re: Do inkjets dither or not?


> Martin writes:
>
> > If the same 256 levels of gray pixels are fed
> > to the printer and it has four channels each
> > with a different shade of gray ink, it would
> > seem to follow that each channel will print
> > those 256 levels differently resulting in
> > overall tonal interpolation. Lower than 1024
> > but greater than 256.
>
> If an image is printed at its original resolution, the number of gray
levels
> will never exceed the number present in the original.  So if the original
> has 256 levels, the print will have 256 levels as well.

Anthony,

Even when it is converted to CMYK and with six different shades of gray ink?
I think that it would be highly unlikely in any circumstance that input
exactly matched the output.
>
> If an image is printed at a resolution different from the original, or if
it
> is manipulated in any way prior to printing as part of the printing
process,
> the printed version may have more gray levels than the original.

The data is always manipulated when we print. This is the function of the
printer driver and is the only way we can print gray scale or RGB or even
CMYK files to out CMYK and CcMcYK printers. I am sure that even the dye-sub
printer drivers are manipulating the data as well.

> The overall quality of the printed image is never improved by this
process, but
> it may enhance the visual impression created by the print.

If the visual appearance of the print is enhanced then what else do we need
to be concerned about?

>  For example, if
> the original has only half the resolution of the printer, the printer or
its
> driver may interpolate the original to produce a printable version with
> higher theoretical resolution.  This interpolation will typically involve
> creating new pixels that may have gray levels intermediate to those
present
> in the original; so an original with 256 levels may be printed as an
> interpolated image with 1000 gray levels or more.  However, this doesn't
> improve the quality of the image; it simply makes pixellation less obvious
> in the result.

But it does improve the appearance of the print to the point that they are
of photographic quality. Beyond that I don't see that it matters. I am
getting more information out of my negatives by scanning them and printing
them with inkjet than I can get from my enlarger.

>
> There are no circumstances in which printing with more gray levels than
the
> original image contained results in a better printed image (in terms of
> resolution or useful tonality).  You cannot create useful information that
> was not already in the original image.  There are no exceptions to this
> rule; it is a consequence of information theory.

If the information being created results in a more pleasing print then I
would say that is the exception to the rule. This is photography and not
information theory after all and it is only the quality of the end result
that counts. The camera, negative, scanner, software and printer are all
simply tools for artistic expression. Understanding how they work is an
important part of the craft but only to the extent that it allows us to
influence the end result.

At this point I gather that most people on this list find the B&W digital
output from the inkjet printers and other technologies to be extremely
satisfying. After all that is why we are here to see what we can learn from
each other to improve our printing techniques. I believe a good portion of
us feel that the output from the inkjets and digital contact neg processes
equal or exceed traditional printing, or we would not have switched.

It seems that you do not agree and are still looking for a way to go digital
with your printing. If inkjet does not meet your own standards, why not try
one of the other approached such as contact negatives from imagesetters to
make silver prints, have enlarging negs output from a LVT or try having your
files output on one of the "laser enlargers".

Martin Wesley