Digital BW, The Print

I'm scanning some old slides to be made into B&W prints.  I have the
impression if I scan them in "grayscale" mode I'm probably only getting the
green sensors and green information out of the slide.  Is that correct?  If
so, I suspect I'm far better off scanning in full 16 bit color and
converting later.  (Although medium format RGB 16 bit files start to get
slow to work with on my PC.)

 

Paul

www.PaulRoark.com <http://www.paulroark.com/>  

 



[Non-text portions of this message have been removed]

Paul Roark wrote:
> I'm scanning some old slides to be made into B&W prints.  I have the
> impression if I scan them in "grayscale" mode I'm probably only getting the
> green sensors and green information out of the slide.  Is that correct?  If
> so, I suspect I'm far better off scanning in full 16 bit color and
> converting later.  (Although medium format RGB 16 bit files start to get
> slow to work with on my PC.)
> 
>  
> 
> Paul
> 
> www.PaulRoark.com <http://www.paulroark.com/>  

In Vuescan the green part of the data collection is increased
in a greyscale scan. I don't know what other software does. I
doubt it would be wise to completely eliminate the red and
blue part in view of the signal/noise ratio if no multi-sampling
  is done.
Converting the color scan later on is better in this case.

I tried to make some profiles that allowed a conversion from 
AdobeRGB to the QTR RGB Lab space along the spectral 
sensitivity curve of specific films (Tri-X etc) but that asks 
for more knowledge. Would be nice though to do that in one 
step. There was solarisation in some cases, in other cases the 
greywedge translated incorrectly.

                    --
           Ernst Dinkla


www.pigment-print.com
(         unvollendet         )

Personally, I like to scan slides in RGB and throw away the data later... It
does eat up space however... Currently I have four 250 Gb drives with
various types of photographic data on them. That's not so bad, but the
archival and backup of that much data is problematic.

I think it may depend on which scanner you are using and what software as to
how it determines the grayscale values -- whether it takes the green values
only only or whether it averages luminance over all three RBG channels and
combines them. Leaving the decision until later allows you, as the artist,
to make the final determination of how to affect the conversion, whether you
use Channels in PS, a third party plug-in, or a Lab conversion. All work;
it's mainly personal preference I think.

And I'm a Mac guy ;-p

Jim 
-- 
parkerparker :: design | photography
http://www.parkerparker.net


On 12/23/05 4:40 PM, "DigitalBlackandWhiteThePrint@yahoogroups.com"
<DigitalBlackandWhiteThePrint@yahoogroups.com> wrote:

> Subject: Scanning slides for B&W
> 
> I'm scanning some old slides to be made into B&W prints.  I have the
> impression if I scan them in "grayscale" mode I'm probably only getting the
> green sensors and green information out of the slide.  Is that correct?  If
> so, I suspect I'm far better off scanning in full 16 bit color and
> converting later.  (Although medium format RGB 16 bit files start to get
> slow to work with on my PC.)
> 
>  
> 
> Paul