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Digital BW, The Print

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RE: [Digital BW] Re: Convert to B&W plugins

2002-12-04 by Austin Franklin

Hi Stan,

> Austin:
> Do you seriously mean did I look at the image???
> What else would I do? Am I missing something here?

It wasn't meant that if you didn't, you were a dunderfutzen!  It wasn't my
first thought do simply thumb through the channels...

> I am fairly competent in Photoshop, have been printing traditional color
> and black and white for about 40 years and have studied with Ansel
> Adams. My monitor is carefully (and regularly) calibrated with an
> EyeOne, I build profiles with real software and take my vitamins and
> Wheaties each day.

OK, you get a gold star!

> Despite this, I still see only very minor differences
> in the channels of a grayscale image scanned as a color neg and I
> attribute these to a base color.

I'm not sure what you mean by "base color", as in the actual color of the
film?  The majority of differences I saw in the one B&W negative I scanned
as RGB were in the mid-tones.  How would the base color manifest it self
prominently different in the mid-tones?

> A grayscale is just
> that..gray.neutral.no color, and if someone can show me how scanning a
> BW neg as an RGB image would allow any (other that very minor) changes
> in the image, I'd love to learn this.

Perhaps you could explain why "convert to grayscale" in Photoshop uses a
"mix" of the three channels, instead of just using one...

The scanner (at least all but the Leaf, that I am aware of) scans everything
as RGB anyway...whether you have selected B&W or color, and then converts
the RGB data to grayscale using some canned "mix" of the three color
channels.  Perhaps there is a scanner that simply takes one of the color
channels and calls that grayscale...and sends you only that channel when you
ask for grayscale data.

What people are saying, is they get better results by getting the RGB data
from the scanner and applying their own "mix" of the three channels in PS
when they convert to grayscale.  This makes sense, as different films will
have different "colors", and simply using a single mix in the scanner will
give inconsistent results across films.  I also believe you certainly can do
at least as equal a job in PS using your own mix, if the mix the scanner has
chosen happens to be perfect, but somehow I doubt it, so it leads one to
believe you certainly could do better.  It's also subjective.  What's
important in the image to one person (such as using a lot of the red channel
may make the image fuzzier) may be different to another.

Regards,

Austin

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