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
