Digital BW, The Print

Austin -- The mere fact that some prints have more tones than others 
doesn't have anything to do with the dynamic range of the medium 
(digital inks on paper) does it?   

Don't we have to distinguish between the dynamic range in the digital 
image itself (i.e., in its electronic form) and the dynamic range of 
the analog image that gets printed by a digital system?  For example, 
a black and white digital image may be composed of four different 
tones (in the computer) and when it's printed the image on the paper 
displays four different tones.  But that doesn't tell you anything 
about the dynamic range of the printing process (i.e., the 
combination of printer driver, digital printer, ink, and paper).  

For that you'd need to get an electronic image that itself had more 
tones than could be distinguished in the image of it that gets 
printed, AND you'd have to compare the two and see that the printed 
image doesn't have as many tones as were present in its electronic 
representation. Then you'd know that the paper/printing process had 
lower dynamic range than what was present in the electronic image.  

Isn't this related to the process of calibrating our printers with 
256 step wedges, making sure that each of the tones is 
distinguishable from the rest AND THUS maximizing the dynamic range 
of the printing system?  We can't tell whether the dynamic range of a 
printing system is low just because we see an image it printed that 
has low dynamic range (the source image might be the link with the 
low dynamic range).  But we can tell that a system has high dynamic 
range if we see an image printed by it that has subtle gradations in 
tone (dynamic range is at least as great as what's observed in the 
printed image).

Question:  assuming that we can calibrate digital printers to 
distinguish between the 256 shades of gray in a step image, how much 
more dynamic range is there in them?  We can use source images with 
up to 2^16 shades of gray in Photoshop (what is that, 65536 
shades?).  Can any of the print drivers make use of the extra bits?  
If so, then we could test just how much higher the dynamic range 
was.  

-- Herb
   



--- In DigitalBlackandWhiteThePrint@y..., "Austin Franklin" 
<darkroom@i...> wrote:
>I've
> always talked about dynamic range and number of tones in analog 
imaging.  It
> really doesn't take an eagle eye to see that some prints can have 
more tones
> than others!
> 
> Austin