I'm not tryng to score debating points Adam. Merely citing an example
of how one very good retoucher works. She can alter the color response
very effectively by changing the color before conversion. She can also
do it by masking individual areas -- a sky for example -- and altering
the tonality after conversion. Her method isn't necessarily simple. It
can be quite complex. I only mentioned it as an aside. What I did say
was that you can achieve a very nice conversion by using the photoshop
grayscale conversion and then applying tonality adjustments with curves
after conversion. It will give you results that are indistinguishable
from what can be achieved with the channel mixer in most cases.
Paul
On Oct 31, 2005, at 8:47 PM, Adam Maas wrote:
Paul,
That's an argument to authority. And incorrect. I'm sure she's quite
competent, but in this case, she's also wrong. This is the sort of
argument that I see very often among computer consultants.
Simply put, her method simply can't deal with an image that would
require filtration with B&W film. Even my basic channel mixer method
(which takes maybe 10 seconds longer than her method for most images)
allows me to balance the three channels to taste. Her method allows
tonality adjustments to the final mix, but absolutely no adjustment of
colour response which, as most serious B&W Film shooters will attest,
can be extraordinarily important to a final image. considering that
many people used to choose film just for it's colour response (See the
difference between SFX200, Tri-X 400 and an Orthochromatic emulsion
for starters)
-Adam
Paul Stenquist wrote:
No, you're incorrect. My retoucher friend knows exactly what she's
talking about. She does fantastic work and is in great demand among
pro shooters at about $200 an hour. Sometimes she will go back and
alter the color image to change the conversion , but she's more
likely to tinker with it after the fact. She frequently uses curves
and masks after the fact if more control is needed. But she points
out that the PhotoShop grayscale conversion provides an accurate
translation of a given color scene. It's quite close to what the
values would have been if shot without filtration. She did the
conversion and some after the fact tuneup on my shot of the shoe
shine man. http://www.photo.net/photodb/photo?photo_id=3451662
On Oct 31, 2005, at 5:25 PM, Mark Roberts wrote:
Cotty <[EMAIL PROTECTED]> wrote:
On 31/10/05, [EMAIL PROTECTED], discombobulated, unleashed:
Thanks to all who commented. By the way, this BW conversion was
done the
fast and easy way: A simple mode change to grayscale followed by
adjustment of the tonal range in curves. In that this simple
procedure
allows complete control of tonal range and that any more elaborate
method
takes you to the same place -- grayscale -- I fail to see the need
for
elaborate "recipes." I mentioned some of these elaborate
procedures to a
professional photo retoucher a couple of weeks ago. She simply
said,
"That's all a lot of bullshit for people with too much time on
their
hands." That being said, I sometimes use the channel mixer because
it's
fun. But I don't think it's necessary.
That's very interesting you say that. I have often suspected it.
But it ain't true. This "professional photo retoucher" doesn't know
what
she's talking about. There are some tonal changes that can *only* be
accomplished before the image is converted to grayscale. That's why
those of us who use B&W film often use color filters when shooting.
A trivially simple example: You can paint an object in 3 shades of
gray,
red and green each of which will translate to exactly the same shade
of
gray with a particular B&W film or greyscale conversion. Once the
image
is in greyscale, you can play with the levels and curves controls
until
the heat death of the universe without them ever changing in
relation to
each other, but using a color filter when shooting B&W film, *or*
adjusting color balance in Photoshop before converting a color image
to
greyscale, will give you control of their relative density. This
applies
to all colors to some extent, and control over these characteristics
are
what the channel mixer procedures and other recipes accomplish.
What you're dealing with isn't "bullshit for people with too much
time
on their hands" but rather "bullshit from a photo retoucher
attempting
to conceal a lack of understanding of some very basic photographic
concepts".
BTW: You can't use digital color balance changes to *exactly*
duplicate
the effects of a physical color filter applied during shooting, but
you
can get pretty close (and that's an entirely different discussion.)
--
Mark Roberts
Photography and writing
www.robertstech.com
