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Fig. 1 -The "moon buggy" is a general purpose wheeled
cart used on film sets. It resembles the MET transporter that was
used on Apollo 14. (Zig Zag Productions and Clavius)
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This and the following pages describe the webmaster's involvement
with the production of The Truth Behind the Moon Landings from
Zig Zag
Productions. The webmaster participated in only one segment of
the program.
THE MOON BUGGY
While hauling rocks around the set in order to demonstrate certain
shadow effects, the webmaster noted some interesting aspects of the
lighting provided by the single large 18 kW studio light. These
features mimicked some of the lighting effects seen as "anomalous" or
"problematic" in Apollo photography.
The cart in which the rocks were hauled is a standard piece of
grip equipment coincidentally called a "moon buggy" (Fig. 1). It's a
bit like a wheel barrow, but fully stable on four wheels. The rocks
we carried in it were reasonable facsimiles (in color and texture) of
Apollo samples taken from the lunar highlands.
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Fig. 2 -The apparently luminous tracks of the "moon
buggy" in the desert dust. (Zig Zag Productions and Clavius)
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Fig. 3 -The Apollo 14 MET leaves glowing trails on the
lunar surface. This photo is shot mostly up-sun. (NASA:
AS14-64-9057 detail)
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In Fig. 2 the camera looks back along the path of the buggy from
the truck in the direction of the light, or "up-sun". The tracks made
by the pressurized rubber buggy wheels seem to glow; they are markedly
brighter than the surrounding terrain.
The same effect can be seen in the Apollo photograph in Fig. 3.
The MET has been pulled along with the astronauts, and the astronaut
has taken a photo looking back along where they came from.
The tracks appear to glow because of a combination of phase
effects and texture effects. When the light comes principally from
one direction, objects are strongly lit on one side and strongly
shaded on the other side. This applies also to elements of a textured
surface: the little hills and valleys that make up the texture.
If you happen to be looking into the sun (up-sun), you're seeing
the shaded sides of the texture elements. The individual elements are
too small to see in photographs. But the overall cumulative effect of
seeing only the shaded sides of all those tiny texture elements is a
dim surface. The same effect doesn't occur if you're looking away
from the sun (down-sun) because you're seeing the lighted sides of all
the texture elements.
If you mash the texture flat -- by rolling over it with a tire,
for example -- the effect largely goes away too. And so the now
smooth surface presents no shaded sides to the viewer and, in the
cumulative effect, appears much brighter.
In our reconstruction the tracks don't appear as light because the
dust in the California desert is not as fine as the dust on the moon.
So the moon buggy wheels weren't able to mash it as flat as dust can
be mashed on the moon.
PUTTING THE TEXTURE
THEORY TO THE TEST
Those texture effects happen on Earth too, especially when the sun
is low in the sky. But because of atmospheric diffusion, the
difference between light and shade is not as pronounced on Earth as it
would be in space, so the effect tends to go unnoticed.
But since we had a textured surface and a directional light
source, we were able to test the theory. In Fig. 4 a grip is
assembling the dolly track that will be used later to shoot
videotape. The ground in front of the track shows the original
texture of the desert floor mixed in with the texture created by
footprints. Note the wood scraps.
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Fig. 4 -The general desert floor texture looking into
the light. (Zig Zag Productions and Clavius)
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In Fig. 5 the same patch of ground (note the wood scraps) is
photographed from exactly the opposite direction. In the area near
the photographer's head -- where the phase angle is nearly zero -- the
desert floor appears textureless and thus uniformly bright. Even
though the exposure settings are the same, the ground in Fig. 5
appears brighter in the frame than the ground in Fig. 4.
Note also the gradual increase in visible texture toward the
bottom of the photo. The phase angle is increasing, allowing the
camera to "see over the top" of texture elements to their shadows.
Farther in the distance, where the phase angle is close to zero, the
objects hide their own shadows.
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Fig. 5 -The general desert floor texture looking away from
the light. (Zig Zag Productions and Clavius)
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Here the texture elements are big enough to see. The same is
true in other Apollo photographs that are considered problematic.
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Fig. 6 -The view out of the Apollo 11 lunar module
looking down-sun. (NASA: AS11-37-5454)
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In Fig. 6 the camera is looking down-sun. The surface appears fairly
bright and uniformly smooth. This is because the same thing is
happening here as is happening in Fig. 5. The texture is there, but
it is invisible because of the small phase angle.
Fig. 7 represents the photos considered to be anomalous because
they show an apparent fall-off of light on the surface toward the
horizon. In other words, conspiracists argue that this must have been
taken with artificial light because artificial lights lose intensity
the farther you get from them.
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Fig. 7 -The famous photograph of Buzz Aldrin.
(NASA: AS11-40-5903)
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This one especially is interesting because of the bright patch
just behind Aldrin. As we've learned, the loss of texture gives us an
increase in apparent brightness, if we happen to be looking up-sun as
we are in Fig. 7. Reconstructing the last moments of Eagle's
descent, we discover that this patch of ground was swept by the
exhaust from the descent engine a few seconds before touchdown. That
erased a lot of the texture and therefore we see the same sort of
effect as in the tracks in Figures 2 and 3. The tracks have a sharper
edge that makes them more prominent than the soft-edge exhaust
effect.
But the general darkness of the surface and the falloff toward the
horizon have prosaic explanations in the behavior of the texture when
lit from a low angle. As seen in our experiment, the ground appears
darker when the textures are backlit. Looking up-sun makes the ground
darker when the lighting angle is low.
The falloff occurs because the general roundedness of the lunar
surface is more pronounced than Earth's. The moon is smaller, and the
horizon is closer. It curves away faster, increasing the phase angle
and thus increasing the texture darkening effect.
THE WORST CASE FOR
DIFFUSE REFLECTION
Conspiracists get a lot of mileage out of the presumption that
reflected light from the lunar surface -- being only about 7% of
sunlight -- is not sufficient for fill lighting. Typically they don't
do experiments to verify this. And we've yet to see any photometry
calculations other than the handwaving reference to albedo. When they
do present empirical data, it's only the data that supports their
interpretation -- stark shade in a few selected photos that were
underexposed. The conspiracists never seem to do any experiments that
test their conclusions. So we have to.
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Fig. 8 -A rock in the moon buggy photographed with
normal exposure.
(Zig Zag Productions and Clavius)
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In Fig. 8 the photographer placed a rock in the moon buggy and
arranged the buggy so that the rock was shaded not only by the back of
the buggy, but by its sides so that no light entered either directly
from the light source, or indirectly from the desert floor. At normal
exposure settings the rock was essentially invisible.
In Fig. 9 the camera exposure was augmented to admit more light.
Predictably the rock was visible in the photograph, but other portions
of the photo -- such as the surface -- were "blown out" and lost a lot
of their detail. This is the dilemma photographers face when they use
film with narrow exposure latitudes. They must often choose whether
to lose detail to shade or lose detail to brightness.
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Fig. 9 -A rock in the moon buggy made visible by
intentional overexposure. Note the loss of detail in the brightly
lit terrain. This is an inevitable side-effect of overexposure.
(Zig Zag Productions and Clavius)
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The important thing to understand from these two photographs is
the role of exposure in the final
appearance of a photo. The ability of the photographer to adjust the
camera and affect the apparent brightness of the final image makes
casual inspection of a photograph a poor method for determining what
the original scene must have looked like to the naked eye, and
consequently whether artificial light must have been used.
Astute photographic interpreters look for signs like "blown out"
detail to determine if a photograph was over- or underexposed, and
from there to calibrate the likely visual appearance of the original
scene. Conspiracists, on the other hand, blindly assume that the
photograph is always a true representation of the brightness and
contrast that the naked eye would have seen. Then they try to
attribute the different appearances to artificial lights or other
nonsense.
The photographer here theorized that reflected light from his
clothing might be affecting the overall lighting. Fig. 10 is the rock
in the buggy photographed from a position where the photographer
himself did not contribute to the lighting. The exposure was set to
make the rock barely visible.
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Fig. 10 -A rock in the moon buggy photographed from
behind, slightly overexposed.
(Zig Zag Productions and Clavius)
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In Fig. 11 the photographer has moved into a position where the
directional light is fully on his clothing, and thus providing fill
light to the rock. The exposure settings were the same as in
Fig. 10. The results show that if an astronaut is standing in the
sunlight photographing a nearby shaded object, his space suit will
contribute quite a bit of fill lighting to the overall scene.
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Fig. 11 -A rock in the moon buggy with the
photographer's clothing providing additional fill. Same exposure
settings as Fig. 10
(Zig Zag Productions and Clavius)
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The ultimate in suit fill is shown in Fig. 12. The ground at the
astronaut-actor's feet is completely shaded from the singular studio
light approximately 200 feet (70 meters) away. But the diffuse
reflection from the suit creates a pool of illumination at his feet.
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Fig. 12 -An actor's space suit replica casts a pool of
reflected illumination at his feet.
(Zig Zag Productions and Clavius)
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But you took your
photographs on Earth, in an atmosphere. The reason you can see the
rock in the "moon buggy" is because Earth's atmosphere is diffusing
the light.
That's a misunderstanding of the diffusive properties of Earth's
atmosphere and their effect on lighting. Yes, air will diffuse light,
but only when there is a tremendous thickness of air. It takes dozens
of miles of atmosphere to create a noticeable diffusion. Even then
only a very small percentage of the light is diffused.
We notice it on Earth's surface because we're at the bottom of
many miles of atmosphere, and because a small percentage of sunlight
-- which is very bright -- is a noticeable amount. The result is our
blue sky. (Blue light scatters more easily than red light.)
The glowing blue sky does indeed contribute to indirect light on
Earth. That's why we can see things in shade and shadow. And so if
atmospheric diffusion is responsible for the indirect light in our
photographs, we have to ask why it softens only shade and not shadow.
The shadows of objects cast onto the ground are still pitch black, as
we would expect them to be if the ground itself is the source of
indirect light. Further, we vary the positioning of the physical
reflectors and note a change in the indirect lighting. This confirms
the source of the indirect lighting as the physical reflectors.
The 200 feet (70 meters) of air between the light and the rock is
simply not enough to produce any kind of significant secondary
lighting by diffusion. The diffusion principle applies only to
sunlight through the full thickness of Earth's atmosphere, resulting
in a blue glowing sky. It has no measurable effect on studio lighting
at night.
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