Re: Nikon D-1 Colorsync workflow
Re: Nikon D-1 Colorsync workflow
- Subject: Re: Nikon D-1 Colorsync workflow
- From: Dan Reid <email@hidden>
- Date: Wed, 01 Nov 2000 11:08:39 -0700
On Fri, 27 Oct 2000 10:46:23 -0700, John Gnaegy <email@hidden> 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 Gnaegy
>
email@hidden
>
colorsync testing, colorsync user list
Digital camera profiling is about describing how the *camera* responds
to color and not light spectral energy or exposure variance.
The DC Colorchecker is an excellent chart because lighting spectral
energy does not influence the matte color patches. On the other hand the
glossy patches on the chart *are* effected by the lighting conditions and
strong colors on the set. Manually excluding these patches from the chart's
reference file eliminates them from influencing the profile calculations. As
long as white balance is maintained and exposure optimized (calibration)
then the DC profile will be valid.
But what if the photographer under or exposes and decides to retain a
color cast? Should the DC profile be valid, or should a new one be created
for that location shoot?
In DC profiling you want to characterize how the camera responds to
ideal exposure and white balance. The original DC profile is still valid
because we want to retain the creative decisions for lighting and exposure
and not nullify them by creating a new profile that *compensates* for the
scene.
--
Dan B. Reid
RENAISSANCE PHOTOGRAPHIC IMAGING
Color Imaging Solutions Provider
http://www.rpimaging.com | email@hidden
Toll Free: (866) RGB-CMYK [ 866-742-2695 ]