Digital BW, The Print

----- Original Message -----
From: "thedigitaldog" <andrew@...>
To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
Sent: Friday, October 11, 2002 2:18 PM
Subject: [Digital BW] Re: 'combed' histograms in 16 bit ?


> --- In DigitalBlackandWhiteThePrint@y..., "Austin Franklin"
<darkroom@i...>
> wrote:
>
> > But the histogram IS an 8 bit histogram...  It should look the same,
> > providing no tonal adjustments are done, and I don't believe simply
> > converting from 16 bit to 8 bit should do that...it only "lops" off the
> > lower 8 bits.
>
> Photoshop shows all histograms as "8 bit." If it had to show you a level
for
> every possible step in 16 bit (64000 odd levels), the display would have
to be
> the size of a small bus! So when you view a Histogram in high bit (what
> Photoshop calls 16bit), you're not seeing what is really going on in that
> Histogram. But you still have all the data in that file to manipulate.
Once you
> convert to 8 bits per color (on a copy), now you are seeing the "real"
> distribution of the 256 levels of data. So the combs should be long gone.
>
> Bottom line is that when you have a high bit file and you manipulate it,
you
> can use the Histogram provided but the preview showing the data or combing
> isn't accurate. You still have many, many steps that end up producing the
best
> 256 levels once you convert down to 8 bits and you should see a nice,
> smooth histogram.

Andrew,

You are right but what about all the people who work entirely in 16-bit
mode? Or like myself stay in 16-bit as long as possible before going to
8-bit? On a couple of negs I have been forced to stay in 16-bit to get the
tonality I want. Adobe is really missing the need for full functionality in
16-bit for critical B&W work. 8-bit color is fine because you really have
24-bits of data to push around. 8-bit is cutting it much to close for
comfort.

Martin Wesley