Digital BW, The Print

Yes, size matters.
Imagine a smooth gradient, across a cloudless sky for example.  It came from
a very clean drum scan of tech pan at 16-bit.  Now you downsample to 8-bit,
_without_ dither, and this gradient goes from 226 to 240 i.e., 15 steps.  It
’s a large print, so this section is 15” long.  That’s one 8-bit step per
inch.

Now, what does the printer dither pattern do at the distinct transition
between steps?  A very keen eye might see posterization, which can be
“corrected” by adding noise to the image.
If you did not downsample to 8-bit, you would not have the need to “fix” the
posterization because the step size is well below human eye detection.

The same print is now much smaller, and the gradient is only 0.5” long.
There are now 0.5/15 steps per inch, or about 0.033” per step.  The printer
dither over this short distance will blend in with the adjacent steps,
making it much harder, if not impossible to see.

This of course depends on your RIP, paper, profile, and image.  Tyler has
commented in the past that “better” systems can actually look worse, for
cases like this, since the system is finely tuned to put down precisely what
is in the file.  I hope I have not misstated his point with this example.
In any case, it is very subtle, and you need to be looking hard it to find
it.

Best regards,
John Moody

-----Original Message-----
From: DigitalBlackandWhiteThePrint@yahoogroups.com
[mailto:DigitalBlackandWhiteThePrint@yahoogroups.com]On Behalf Of john dean
Sent: Monday, November 13, 2006 3:50 PM
To: DigitalBlackandWhiteThePrint@yahoogroups.com
Subject: [Digital BW] Re: the times, they aren't a-changing-so can we start
over again?

16 bit output?

Would the size of the print come into play in this?



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