|
|
Definition: chiaroscuro: [It., f. chiaro clear, bright + oscuro dark, OBSCURE a.].
2 The treatment or disposition of
the light and shade, or brighter and darker
masses, in a picture; an effect or contrast
of light and shade in a picture or in
nature. L17. [The Oxford Interactive Encyclopedia.
(c) 1997 TLC Properties Inc.]
|
Since at least the Renaissance (but maybe
earlier and we just do not have any
physical evidence) it has been customary
for painters to do tonal studies, black and
white sketches while planning the
composition of future major works.
Chiaroscuro is arguably the most powerful
technique at a painter's disposal for
evoking mood with-in the composition. [ see here for others ]. The mood so created by the play of light and shade within the composition, has the added advantage of being independent of any culturally biased colour symbolisms.
By
the mid nineteenth century different tonal
schema had come to-be associated with
particular genres (classes of subject
matter) of paintings, or works by a given
painter during phases of the life, such as
Goya's black paintings, or Rembrant's
golden landscape. Then in the mid twentieth
century a musical metaphor of scales
was employed to distil the various
templates like "camp fire scene", "bright
sunny day" into approximately eight 'tonal
keys'. The terminology 'tonal key'
was unsatisfactory for a number of
educational and other reason, so [ as explained elsewhere ] I settled on the designation "value regime".
But before examining 'value regimes' one needs to better
understanding of what exactly is meant by 'value'. Traditional
discussion of this topic was clouded first by a dichotomy of
'highlights & shadows' or 'light & shade'. 'Tonal steps' then
became the common description, but 'tone' was exclusively
associated with achromatic (non-colour) compositions, with the
dichotomy persisting in the colour realm as 'pastels, tints & shades'.
Over the twentieth century "Value" then slow displaced the previous
clutter of terms to provide a uniform descriptor for gradations of
shading in both achromatic and chromatic worlds.
While not obligatory to any understanding of 'value regimes'
the eleven step gradation of value from absolute black at zero to
blinding pure white light at ten, as applied by Albert H. Munsell is the
easiest to use.
{A note of caution, is that some graphic arts text,
reverse this ordering so that one is the lightest value, as it has negligible cross-hatching to nine being a
lot of cross-hatch and thus the darkest value}.
Limiting our selves to nine (from pigment black at one
to pigment white at nine) value step of the every day world, these can be further clustered as three
bands of three steps each {see figure}The "Low" band is; black (1), 2 & 3, then 4, 5 & 6 make the
"Intermediate" band, leaving the "High" band as 7, 8 and pure white pigment as 9.
|
All 'value regimes' as described by
a two part name. The first part of
the name tells you which band the
greatest part of the composition is in
. If most of the composition is
found to have values in the 'High'
band, then it is proper to speak of a
work as using a 'High value regime'
or to be in a 'High Regime'.
The second part of the name
indicates the importance of contrast
to the schema. It is a common pitfall to regard any and every little highlight or line of shadow within the
frame as critical in determining an image's value regime. Rather what must be focused on is areas of
value that are substantial enough to impact on the overall value schema. There can be no hard and fast
stipulation about how large an area has to be before it becomes significant to the value regime, as the
style (hard-edge versus softer touch), scale and complexity of chiaroscuro within the work all subtlety
alter perceptions of importance. However total areas for a value step around 10% ~ 20% ( of available
surface area) is a reasonable rule of thumb |
So
to ascertain the 'contrast reach' in
question, examine the range in value steps
between, the brightest 'significant' area
compared to the darkest 'significant'
area. A contrast reach of greater than
six steps is designated as a "Major", thus
'Low Major' , 'Intermediate Major', and
finally a 'High Major' are the only three
Major value regimes.
|
Compositions with maximum value reaches less than six steps
make up the remaining five "Minor" value regimes.
High
Minor, Low Minor are fairly easy to understand, High Minor
is a composition that is mainly in the High band with the
darkest value being no lower than the Intermediate. Then Low
Minor is just the reverse of the High Minor situation.. The
three remaining Intermediate Minors are somewhat more
complex.
To recap an Intermediate Minor composition will be
one where over-all impression of the image belongs to the
Intermediate value band, as well as having a Minor contrast,
that is to say a
compressed value range or reach between the brightest
and darkest significant spots in the image field. If the value
distribution is on the lighter side it is a Intermediate-High
Minor (aka High-Intermediate Minor). Whereas if the if
the bias is towards the shadows it is a Intermediate-Low
Minor (aka Low-Intermediate Minor). When the value
range is clustered fairly evenly then it is an Intermediate
Minor (aka Intermediate- Intermediate Minor). {see figure
}.
Returning to the emotive effect of 'value regime' choice,
the Major & Minor Regimes parallel the common association in music of Major & Minor Keys /
Scales. Additionally Major Regimes tend to be dramatic, compared to the some-what subdued Minor
Regimes. Low band Regimes are more depressed, tied or foreboding than other band regimes. High
band Regimes often have a airier, lighter sometimes frivolous quality. But in the final analysis the
emotive potential of value regimes is only one of many visual elements & principals that are artist
marshal's to their creative ends.
|
|