Digital BW, The Print

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Austin 
Franklin" <darkroom@i...> wrote:
> 
> > Think of it this way - at maximum printer resolution it can only
> > represent 46 distinct tonal values in the surface area of the
> > paper
> 
> I'm not sure who wrote this, but it's simply wrong as a general 
statement.
> The printer resolution really has nothing to do with how many 
distinct tonal
> values can be printed, only the dithering algorithm does, and it is
> technically infinite. 

The printer resolution has a LOT to do with how many distinct tonal
values can be printed in a given spot on the paper!  That's why I 
said, above, "in the surface area of the paper".


Imagine a printer with 600 DPI resolution trying to print two gray 
pixels with different values a 600th of an inch apart with just 
black ink.  The best resampler+dithering algorithm in the world 
can't solve that because it would take a pattern of dots to create 
each gray value and the printer doesn't have enough physical 
resolution to make that pattern in that much space. 

Now imagine a printer with 1200 DPI resolution doing it.   If the 
dots were sufficiently different values of gray it could print two 
different-looking adjacent dots but the gray values would only be 
crude approximations because in 1/600th of an inch it can't make 
much of a dither pattern.  

Now imagine a printer with 6000 DPI resolution.  That gives the 
dithering algorithm a lot more to work with so it can do an even 
better job. 

That's why I said all dithering algorithms are tradoffs between 
tonal resolution and spatial resolution.


> If you want more tones, you simply use more area. 

I.e., less resolution.