Creating Themed Environments: How fiber optic lighting can
create a magical illusion of night The creation of a believable
simulated starfield, as with any aspect of environmental effects
lighting, involves the presentation of visual cues designed to
approximate mental pictures stored in the mind of the viewer.
When done successfully, whatever the viewer "sees" is
some version of the stored picture in his or her mind, not the
technical reality of what has triggered that picture. This all-important
mental picture is generally influenced by two factors: 1. Reality;
what we observe about the real world through our senses 2. Media
imagery of the real world experience, which may or may not approximate
reality.
DESIGN CONSIDERATIONS How many stars are really visible in the
night sky?
The vast majority of the population that we must concern ourselves
with lives in suburban settings. Most suburban skies show only
stars brighter than magnitude 4 or 4.5, even at zenith. There
are fewer than 1,000 stars in the entire sky brighter than magnitude
4.5, of which 500 are above the horizon at any one time (actually
slightly fewer in the Northern Hemisphere, slightly more in the
Southern Hemisphere). Of these 500, many will be so low in the
sky that they are either not visible or are hidden by buildings,
trees, or other obstructions along the horizon. Out of all the
stars that might theoretically be considered "visible"
to the naked eye, at any given time, you can probably see only
about 200 at any one time from your home.
Prior to the age of industrialization, under ideal dark night
conditions, far away from terrestrial sources of light, water
vapor or pollutants and surrounded by flat ground, it was theoretically
possible that about 2800 to 3000 stars could be visible to the
naked eye, horizon to horizon in all directions. In the 20th century,
given gradual global increases in pollutants and overall sources
of surface light, few if any of us, even under the same conditions,
have ever seen more than 1400 or 1500 stars at any given time,
throughout the entire celestial "dome". Naturally, to
the degree that only a portion of that "dome" is visible,
the actual count of visible stars could be substantially reduced.
This is reality; but reality is only part of the equation. Very
few of us spend our time staring at the night sky or counting
stars. Idealized images that we carry in our heads influence our
perception of reality. Such idealized images arise out of a variety
of experiences such as occasional trips to rural areas, television
and movie images (themselves idealized) as well as photographs
and renderings in books and magazines, which are almost always
telescopic or space views.
What is the Starfield Distribution Within the Night Sky?
The distribution of stars within any given field of view is truly
random, a fact that the human mind recognizes as a retained image,
even if it never contemplates the fact. That randomness includes
sizable "gaps" or voids in the distribution; significant
areas where no stars or very few stars are visible. In designing
believable starfield presentations, these "gaps" are
one of the most important and problematic elements we must deal
with. The modern human seems to abhor a void. Without external
controls, this quirk of human nature tend to make us want to fill
in such voids, a fatal mistake where starfield design is concerned.
The natural gaps or voids that occur in nature are critical to
the believability of the presentation.
Knowing our distinctive "fill in the gaps" tendencies,
we can see that we must employ some form of external template
or control that precludes human rationalization during the critical
design process.
Star Magnitude?
Astronomers describe the brightness of stars with a scale built
on a historical base which has it origins in ancient Greece and
which has been mathematically refined through the centuries. While
a few stars are brighter that Magnitude "1", the brightest
designation of old, the visible range of star magnitudes can be
said to run from Magnitude 1 at the brightest to Magnitude 10,
the very faintest. Magnitude 6.0 is generally accepted as the
very faintest magnitude visible to the naked eye under the darkest
and most ideal conditions, even in ancient times. In the 20th
Century, a magnitude of 5.5 seems to be the extreme limit of visibility.
Each whole number increase in the magnitude scale represents an
increase in overall light energy of 2.51 times the next lower
magnitude. Interestingly, (and fortunately, for us) the relationship
of fiberoptic conductor sizes follows an almost identical pattern,
with each size producing 2.5 times the total light output of the
next lower size.
Why do stars twinkle?
Planets usually seem to shine steadily while stars twinkle. Twinkling
is an effect of turbulence in the earth's atmosphere; the atmosphere
bends the starlight passing through it and, as small regions of
the atmosphere move about, the intensity of a star's light varies
slightly but rapidly. The reason why stars twinkle and planets
do not is because stars are so far away that they look like points,
even when viewed through large telescopes. Planets, though, are
close enough to earth that their images are tiny discs. As the
light from each different part of a planet's disk twinkles, it
averages out and makes the planet appear relatively steady in
both brightness and position. The key message here is that stars
shimmer, they do not blink on and off. Any attempt to duplicate
a starfield must accurately reflect this characteristic shimmer.
Methodology?
Each starfield design starts with careful considerations of the
space within which the starfield is to be created. Context, ceiling
height, available field of view and type of activity within the
space are all factors which play heavily upon final recommendations
as to how the scene should be set. The first question that must
be answered is "Is this to be a terrestrial view or one,
which would be typical of a "porthole" view from outer
space?". The answer to this point provides us with the proper
"context", a key foundation for our efforts.
Ceiling height and field of view are additional key factors. They
define the portion of the "celestial dome" that a viewer
would see from any given point. That input can then be translated,
at scale into actual starfield distribution within that specific
ceiling area.
Anticipated use of the space is also important. A passive audience
within a seated theater format with extended periods of waiting
time prior to or during a performance would suggest a presentation
quite close to actual reality. In such a setting there is the
opportunity for gradual absorption of the overall scene and we
find that very little reality is necessary to produce a believable
and satisfying effect. On the other hand, guest on a moving dark
ride, encountering a starlit scene for only a few seconds, as
part of a succession of high impact images and scenes, will require
a much exaggerated depiction to produce the same level of recognition
and believability.
The use of active, dynamic effects is a final consideration. Nothing
gives vibrancy and life to a night sky scene like animated special
effects appropriate to the context and setting of the space. The
most basic essential form of animation is, of course, the unique
and pearly shimmer typical of all stars. Even here, serious consideration
must be given to the type of attraction or space involved. The
shorter the exposure or the more the theatrical the presentation,
the greater may be the degree of necessary exaggeration.
A second form of active special effect that deserves consideration
within any starfield presentation is the inclusion if "shooting
stars" within the scene. These realistic, proven crowd pleasers
provide an unquestionable and unexpected sense of realism that
never fails to amaze viewers of the scene.
Other active effects that can be employed include ghostly swirling
"nebula" effects, exploding "novas'" and quite
realistic aerial fireworks displays, complete with synchronized
digital sound effects.
Truly, fiber optic lighting is a valuable and necessary tool for
the successful creation of many themed environments.
Written by Terry Zinger and his staff of fiber optic starfield
experts