Lightness and Brightness and Other Confusions

measured either trichromatically with a colorimeter or, for an even more
precise result, with a spectrophotometer. Both methods can instantly reveal
colour differences that are hard to detect with the naked eye. Another possibility
is to use a visual colour matching system such as Munsell or the NCS. In
the case of measurement, the meter is placed over the target, a calibrated
light flashes to illuminate the target according to very exact preconditions,
and the reflected light is analyzed into components of spectral energy emission
by the meter’s microprocessor. 87 . The result is either a series of three
numbers indicating the proportions of short, medium and long-wave radiation
as detected by the human eye (colorimeter) or a series of some 40 or
more numbers (depending on the precision required) indicating the presence
of radiation at specific wavelength intervals, weighed against a theory of the
spectral sensitivity of the human eye (spectrophotometer). In the case of
visual colour matching the target is compared to a sample from a colour system’s
standardised collection. This too is ideally done under standardised
viewing and lighting conditions.
These kinds of colour measurement provide highly accurate information
about whether a colour is the same or different than a sample or another
target. But does it tell us what is the ‘real colour of the object’? If by colour we
mean what humans see in the real world here and now and in context with
other colours, the answer must be no. Measuring data are abstract series of
numbers that have no connection to the experience of colours in context.
Colour sample matching is a step closer to real experience, but it still misses
out on the contextual issues in perception. As mentioned earlier, colorimetric
and spectrophotometric measurement, as well the underlying CIE-system,
were in fact never developed for precise colour identification, but for the
purpose of attaining highly precise information about colour differences.
Visual colour systems, such as the Munsell and NCS systems, on the other
hand, were developed for the very purpose of providing a reliable system for
identifying, comparing and communicating colours of objects and surfaces in
the real world. Visual colour systems, with their collections of systemized and
standardized colour samples, are no doubt the best way to go about this
task. 88
It was mentioned in the section on vividness of colour (p. 84–91) that colours
can be examined either as non-related or related phenomena. An example of
This may seem like a fairly straightforward physics and maths task, but there are
many hitches and obstacles to be avoided before anything near a ‘correct’ reading is
obtained. Just consider the difference in appearance and reflectance pattern of a piece
of red fabric and polished red metal. The same kinds of difficulty are involved in visual
colour matching.
Painting or high-quality colour photography can render the contextuality and hence
the general impression or ”atmosphere” of spaces and environments much better than
any colour notation system, but this happens inevitably at the expense of accuracy in
real colour, as explained in the above example of the green apple.
94