Digital BW, The Print

Hi, Austin,

Thanks for your thoughtful and helpful reply. 

A couple of questions re: red, green, blue channels. 

1. I've been thinking that the blue channel is the "least sharp," or 
can introduce the most unsharpness into photography, not the 
red, because of the nature of blue light and what happens 
especially with telephoto optics - unless low-dispersion glass is 
incorporated in the lens design. I also thought that this had been 
discussed earlier on the Piezo and Digital B&W groups, and I 
thought I had understood that the blue channel was least 
desirable (am I mistaken?).

2. When I look at the histograms individually for the red, green, 
blue channels from a B&W negative scanned as a color negative 
on the Multi Pro, the histogram for the red channel seems to 
have the highest "spike" in its curve, higher than either the green 
channel or blue channel. This is what led me to consider that the 
red channel, on the Multi Pro, may be giving the most contrast - 
more than the green (which in turn seems to provide  more 
seeming "contrast" than the blue channel). Of course, this could 
also mean the red channel is providing more data in particular 
regions of the scan, and that this is not an indicator or measure 
of contrast at all.

3. What is the basis for the red channel being "fuzzier" and "less 
sharp" than the green? I certainly am happy to use the green 
channel: I'd just like to have a little more theoretical and practical 
information why.

4. What do you know about Vuescan, in terms of how it 
translates the raw scan data into a 16 bit B&W output: does Ed 
Hamrick just select for a single channel? If so, is it the green 
channel? (Perhaps I should ask him directly; just thought you 
might know. Vuescan does list support for Leafscan; do you use 
Vuescan sometimes?)

As for film developer, I have used FG-7 with sulfite at 1 to 15 
most of the time for the past 15 years (I also use Ilfotec when I 
want/need to push HP-5). This is a compensating developer. It 
has worked very well for me (or at least it did in the chemical 
darkroom). I may switch to a more straight line developer, as I've 
largely abandoned the chemical darkroom in favor of Piezo now. 
Most of my work is editorial and documentary (social, political, 
environmental). I exhibit my documentary work fairly widely (30+ 
solo shows to date).

Best regards,
James


--- In DigitalBlackandWhiteThePrint@y..., "Austin Franklin" 
<darkroom@i...> wrote:
> 
> Hi James,
> 
> > I'm finding that I'm getting "better" (cleaner & less grainy look)
> > when I scan my B&W silver negs (Ilford HP-5 & FP4) as color
> > negs.
> 
> That makes perfect sense, since scanning in color will typically 
make for
> softer scans, and therefore will take the "edge" off the grain, 
smooth it
> out...  What developer are you using?  Might I suggest D-76 
1:1?
> 
> > (the red channel seems to give a little
> > more contrast than the green;
> 
> That doesn't make sense.  The red channel is inherently the 
fuzziest, as
> well as the green has inherently the best contrast...typically.  
Green is
> also the sharpest...
> 
> > The
> > scan using the B&W setting looks like it was partially 
solarized;
> > the scan from the color neg setting looks clean and "normal."
> 
> That certainly could be part and parcel of the software...  
Remember, no
> matter WHAT you select, B&W or color, the scanner will scan 
EXACTLY the
> same, it will scan IN RGB, and convert to B&W using its own 
mix, if you have
> selected a B&W output...
> 
> Regards,
> 
> Austin