Digital BW, The Print

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Paul Roark" 
<paul.roark@v...> wrote:
> 
> >... at Bowhaus (the guy behind OPM/IJC) he
> >would work on the photo in 8-bit, and only convert it back
> >into 16-bit for the actual printing. ...
> 
> This must be the reflection of a strange driver/RIP.  It makes no 
sense to
> me otherwise.
> 
> Once you convert to 8 bit you've lost the additional 
information/grayscale
> steps 16 bit can hold.  Conversion back to 16 bits from 8 bits does 
not
> restore those lost steps; it does not add information.  You have the 
same
> number of grayscale steps you had in the 8 bit image, but with a 
file that
> is twice as big.  Why would one do this?
> 
> I agree that 8 bits is all that is needed for a fine B&W print, but 
it is in
> the manipulation stage where there is a major loss of information.  
When you
> apply curves, etc., you lose grayscale steps.  The purpose for 
keeping the
> file in 16 bit as long as possible is usually to have enough extra
> steps/information so that when you're done you have at least close 
to the
> 256 gray levels that 8 bits can hold.
> 
> If you drop much below 256 levels, the quality of the image may 
suffer.
> Take a look at a print of the 100-step test file.  You can clearly 
see those
> steps.  That means that 100 levels is not sufficient for a very fine 
grain,
> clear sky.  (Grain will help to mask this problem if it surfaces -- 
but that
> is not a very attractive remedy.)
> 
> Paul
> http://www.PaulRoark.com

Hi Paul,

What you say makes total sense, of course. Especially since I consider 
you one of the Godfathers of Digital Black and White Printing! I'm 
curious myself. I'm going to forward your opinion here onto Joe at 
Bowhaus and see why he works this way in OPM/IJC. All I know is I 
can't see the difference between his prints he does from 16-bit and 
8-bit files (acknowledging this is irrelevant on photos that have 
already lost the information due to having been converted to 8-bit 
early on.)

Nick

.