Digital BW, The Print

Bruce hit the heart of the matter.  Higher bit depth means a better
result after editing.  When you affect the pixel values in the image
by applying Curves, Levels or other adjustments, the more information
the computer has to work with the better the result will be.  Working
with an 8 bit file, if you make adjustments and look at the histogram,
you're quite likey to see the "comb effect".  The spaces between the
histogram values represent missing information.  Make the same
adjustments on a 16 bit file and the histogram will remain smooth and
continuous.  What this means in the end result is more continuous
tone, better gradation and an overall better print.

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, hogarth@s... wrote:
> How many shades of gray is a religious issue, so I'm not going to 
> address that.
> 
> I will say that how many shades of gray you have to print isn't the
most 
> interesting thing. What is most interesting is how many you have to 
> manipulate in an image editor. If you do much editing at all, such as 
> applying a contrast adjustment curve, having more bits gives the 
> software more to work with, and often results in smoother tones, and 
> less chance of posterization.
> 
> With most manipulations, you end up with fewer individual shades of
gray 
> than you started with. If you start with exacly the number you need, 
> then you end with less than you need. And *that* is why more shades of 
> gray is better than fewer shades of gray, IMHO.
> --
> Bruce Watson
> 
> 
> 
> Seth wrote:
> 
> > I really must differ on that.
> >
> >Since B&W film printing is based on the premise that there are 128
shades of
> >grey plus black and white (and your 150 shades certainly fits
there), 256
> >shades is certainly adequate.
> >
> >If we stay away from those that want to use a loupe, or look at a
16x20 from
> >6" away, we surely accomplish with 256 what was done by the old
masters with
> >130 shades.
> >
> >Seth
> >
> >==-----Original Message-----
> >==Behalf Of Martin Sluka
> >==
> >==Humans recognize about 150 different greys. But problem is, 
> >==they recognize them on full picture and on small detail too. So 8
bits
> >==(256 greys) is not enough for smooth BW picture.
> >==
> >==> In short, the view was that while 16 would be better, 12 was ok.
> >
> >  
> >