Re: filmscanners: File sizes, file formats, etc. for printing 8.5 x 11and 13 x 17...

[Arthur Entlich <artistic@ampsc.com>]

Austin Franklin wrote:

>> There is a big difference between halftoning and dithering.  Most of the
>> printers we use, inkjet, home laser printers, etc, use dithering.
>> 
>> Halftoning involves having each ink color screened into dots and then
>> each of these dots is further matrixed to create different color
>> density.
> 
> 
> Not necessarily.  You are describing an implementation, not a process.  I
> still contend, and what sources I have checked, concur that the process is
> called halftonging, and that dithering is a technique that can be used in AN
> implementation of halftoning.
> 
> 
>> No inkjet printer can produce true
>> halftone, yet.
> 
> 
> I believe you are, again, referring to an implementation of the halftone
> process, namely varying the drop size, as opposed to building the halftone
> cell from a number of dots.

I suspect we are getting into a war of semantics, which, personally, I'm 
not interested in.  I suspect the term halftoning has different meanings 
depending if you are speaking to someone in the fine-art, digital, press 
backgrounds.  I know in speaking to manufacturers and reading reviews in 
press related trade journals, there is always discussion of the eventual 
possibility of inkjet printers producing half-tone screens, but that 
they cannot currently do so.

Words like halftoning probably have numerous interpretations, and it 
would not surprise me that Adobe, a company that came of age in the 
digital realm uses the term in a broader fashion than perhaps it would 
be in the press media.  Ultimately, what is of interest to me, is not 
which term is used, but how the processes might differ, and why, for 
instance, certain lpi and epi cannot directly translate to dpi on an 
inkjet printer, for instance.

Most printers refer to halftone (or the implementation thereof, to use 
your words) which involve a matrix of equally spaced cells which have 
varied dot size.  I would refer to the process used by inkjet printers 
as dithering.  And now I'm going to dither onward... ;-)


> Also, why would inkjet be any different than laser?  They both print in dots
> at a particular resolution.

Some top end high res laser printers (I believe HP owns the patents) can 
actually vary dot size within a set matrix to produce a half-tone 
screen, although the control of dot shape and size on a laser printer is 
still not to the quality of a imagewriter. I was specifically speaking 
of monochrome laser, where there would be no issues of moiré due to 
overlay of several inks. I don't know if any color laser printers can do 
so yet.  Laser printers, using an electrostatic dry toner system can 
produce potentially very small dots, much smaller than the 3-4 picolitre 
droplet inkjets produce.  Further inkjet dots can be quite distorted in 
shape, and bleed in a major consideration, which is very minor with a 
fused laser toner dot.

Although the current line of Epson inkjet printers do have variable dot 
size, hey do not use them in what I would call a half-tone matrix, and 
if they did, the result would be rather course, based upon the dot size.

Art