An increasing awareness of Colour Management issues, (possibly provoked by the changes in Photoshop version 5.0
and the increase in the use of digital images in the professional
workflow) has led
to many customers asking questions about the colour space of the
D-1when images are processed in-camera.
Before addressing this question, it is important to
begin with a clear understanding of the implications of the term
"colour space" and the principles of colour
management.
Colour Management
When a digital image is rendered onto a computer
screen, the particular interpretation of the numbers representing the
values of Red, Green and Blue of each pixel should, somehow, be defined.
If this is not the case, then no guarantee can be given that the image
is being viewed with the same colour interpretation as it moved from
computer to computer, or even program to program. The control of this
mapping of the numerical values of the image to the reproduced colour is
called "colour management", and the goal is to ensure that an
image is interpreted consistently as it passes along a production
workflow.
Colour Space
Any particular mapping RGB values to colours is called a colour space
and the parameters that define this mapping are often stored in a file
called a colour profile.
In the
world of professional colour reproduction, for example in advertising,
working colour spaces must be precisely defined so that product brand colours are
correctly matched with the original article. To ensure this, strictly calibrated
colour profiles, defined by the scientists of the International
Colour Consortium (www.color.org) may be
employed. By adopting the same colour space at each point in the
workflow, the RGB values of the image may always be displayed with the
same visual colour composition.
The D-1 is capable of producing colour in any of the most common ICC defined colour spaces, using the colour management engine of Nikon Capture with
a raw file as input and by selection of an appropriate colour profile.
This method is the preferred and recommended route for any production
environment where the accuracy and consistency of colour is paramount.
The D-1
Although colour management is important once an image has entered a
workflow (for example after critical corrections have been made),
the need is not always so paramount or even possible at the point where
the image is
first viewed and assessed.
For instance, the near-instantaneous in-camera processing of the D-1
body - which is capable of producing a finished JPEG image within about a half
second - does not produce an image file that can be claimed to be accurate to within
the strict scientific limits of the ICC definitions. In this mode, the
camera has been designed for speed of operation, and not as a calibrated
studio device: for that application, Nikon Capture is the appropriate
route.
However, it may be
of use to know that the in-camera processing of the D-1 was designed (in
Japan) in an environment where high quality monitors with NTSC-type
phosphors were employed. This does not mean that the RGB, YCbCr and JPEG
files from the camera are necessarily in a calibrated NTSC colour space, but it does imply that the
closest commonly-available colour environment for D-1 images
produced in-camera will be one
set to the NTSC 1953 profile.
Users who are working in a colour-managed environment might like to
experiment with converting (using Photoshop's "Profile to
Profile conversion" function) D-1 files (produced in-camera) from the NTSC colour space to their
chosen working colour space and assess the results.
