Re: Nikon D-1 Colorsync workflow
Re: Nikon D-1 Colorsync workflow
- Subject: Re: Nikon D-1 Colorsync workflow
- From: email@hidden (Bruce Fraser)
- Date: Sat, 28 Oct 2000 12:53:49 -0700
At 10:46 AM -0700 10/27/00, John Gnaegy wrote:
C. David Tobie said:
Unless you are working in a studio with fixed lighting, and a
custom profile
built for those conditions, then you might as well open the file directly
into your Photoshop workingspace, and adjust visually on a
calibrated monitor.
I'm no photography expert, but are you sure? I can understand that
without controlled lighting and a profile for that condition that
the white point will vary, so it'd be impossible to use one profile
to turn camera-subject-white into monitor-image-white, because
camera-subject-white will vary with time of day outside, lighting
indoors, etc. So you'd have to treat everything like absolute
matching...if it was 5pm when you took the picture of the white
plate on the picnic table, it's going to be a yellow plate onscreen.
But I'd think you'd still want to use a profile to take care of
behavioral anomalies within the gamut of the camera. Let's take an
extreme case, say there's something about the light gathering chip
in your camera that makes it overly sensitive to green, this big
spike in a small section of the green frequency response. That'll
affect all your images no matter what the lighting condition is. If
you had a profile that took care of that then you're back at !
a one to one correspondence of input to output, at least in an
absolute sense. So to test the camera profile I guess you'd shoot
a target in controlled lighting at say 6500, then open the image in
that profile space (softproofing to your screen). The extent to
which image that looks like the original target under 6500 (did you
get rid of that green spike?) should tell you how well the profile
behaved during the softproofing proof operation. I'm just
theorizing here, but does that sound reasonable?
John,
Most of the pro cameras let you do a gray balance either prior to
shooting (preferable) or when you convert the raw camera file (which
with one-shot cameras is a grayscale file) to RGB. Profiles can work
well in controlled lighting situations, but outside of that, just
about every photographer I know has wound up concluding that doing a
gray-balanced capture into a well-chosen working space and editing
from there is an easier and more practical alternative.
Digital cameras don't really have a gamut -- they have a color mixing
function. They'll produce some kind of response to any stimulus that
has enough light for teh sensor to record. Input profiles work well
on scanners (assuming you're actually trying to reproduce the
original, which any scanner operator will tell you is usually the
client request but rarely the client desire) because while the
scanner doesn't have a gamut, the film that's being scanned does. The
scenes at which we point digital cameras don't have a fixed gamut.
In many ways, it makes more sense to treat digicam captures like
negatives -- raw images that have to be rendered for tone and color
-- than like transparencies, where the image has already been
rendered in the capture to film.
Maybe spectrophotometers will get small and cheap enough to embed in
cameras, but until then, unless you're dealing with a controlled
light situation, it probably makes more sense to rely on
gray-balancing and a well-calibrated editing environment.
Bruce
--
email@hidden