Flight 11 For Wise Guys
Perspective Testing The
Introduction
In this article
we will examine the claim that the object seen in the Naudet Bothers
"Fireman's Video" is not a real object because it does not conform to
the laws of perspective.
Defining Perspective
Firstly let's
define "perspective" to find out what people actually mean when they
use the word. The source used here is from the "DK Illustrated Oxford
Dictionary" and includes some graphics.
perspective n. 1 - the art of drawing
solid objects on a two dimensional surface so as to give the right impression
of relative positions, size, etc. 2 - the apparent relationship between visible
objects as to position, distance , etc.
Here's a picture
from the dictionary of Battista Alberti's "The Hunt In
The Forest" (c 1460)...
...and a simpler
graphic using a chessboard:
In our
chessboard example there are lines of demarcation between the black and white
tiles across the chessboard. I've marked in a few of these lines with blue to
make them more noticeable. The further away from the viewer these lines of
demarcation are, the closer together or more compacted they appear to be to the
viewer. You can also see that the black King in the background appears to be
smaller than the white King in the foreground but in both cases the size of
both Kings is identical, as are the distances between the blue lines of
demarcation.
For the purposes
of this article we won't consider the vanishing point but concentrate on
apparent sizes and apparent distances as determining factors in the observation
and measurement of perspective. If these 2 previous examples of perspective are
confusing, don't worry, I'll try and simplify them before analysing the
"Fireman's Video" in such a fashion that it should be relatively easy
to understand, as you'll see in the next paragraph.
Concepts of Perspective for Analysis
Perspective Effect 1 - Increased distance
from viewer produces apparent decrease in size
If you were to
stand on a motorway bridge and watch the cars passing beneath, you would notice
that as these cars get increasing further away from you they seem to getting
increasingly smaller in size.
This is the same
effect as in the previous chessboard example where the black King looks smaller
than the white King because it is further away from the viewer. These effects
are an optical illusion. In reality both the chess piece and the cars
travelling down the motorway have fixed sizes that don't change in relation to
their respective distances from the viewer.
Perspective Effect 2 - Apparent
compacting of linear spaced objects with increase viewing range.
If we assume
that the cars are travelling at a more or less constant speed down the
motorway, then as the cars get further away the distance between each car
appears to decrease from the viewers point of view.
It's as if the cars are clustering together tighter and tighter together as
they travel further and further down the motorway.
This effect is
similar to the blue lines of demarcation between the white tiles and the black
tiles on the chessboard that appear to be closer together the further they are
from the viewer, as if they are compacting themselves. These effects are an
optical illusion. In reality the distance between the cars remains constant if
we assume they are travelling at a constant speed. The distance between the
lines of demarcation on the chess board remain the same regardless of how far
they are away from the viewer.
Analysing the Flying Object in the Fireman's Video
Now that we have
some 2 simple definitions of perspective handy we can turn our attention to the
flying object seen in the Fireman's Video.
If the flying
object is to conform to Perspective Effect 1 then it should be larger when it
first appears in the camera's field of view and smaller when seen just before
it disappears into WTC1. In other words it should decrease in size at it moves
further away from the camera.
Here's the
exercise repeated again with a different scale:
The flying
object conforms to Perspective Effect 1 in that it decreases in size as it
moves away from the camera.
If the flying
object is to conform to Perspective Effect 2 then the apparent distance between
each image of the flying object shown at linear time intervals should decrease
as it moves further away from the camera and towards WTC1, resulting in the
"compacting" effect, just like cars on the motorway as they move
further away from the viewer.
In each of the 2
images below the flying object has been captured at regular time intervals and
has been measured from a fixed point on the flying object. It is highly
unlikely that the flying object would have experienced any significant change
in air-speed over the time interval analysed. We are therefore assuming that
the speed of the flying object is constant.
Here it is again
with a repeat analysis using different frames from the video at linear points
in time and at a different resolution:
In both examples
the flying object conforms to Perspective Effect 2 in that the apparent
distance between each successive image of the flying object captured at regular
time intervals is decreasing resulting in an apparent "compacting"
effect of the flying objects as they move further away from the camera.
Question…
Why does the
flying object look as if it does not conform to the laws or perspective when it
obviously does?
Answer …
When we look at
the flying object in the "Fireman's Video" we probably don't view
each individual frame in relation to one another. Perhaps we prefer to watch
the video at full speed, or in slow motion observing the frames in a linear
fashion just as we would have seen the flying object in reality (assuming of
course the video is not a fake). The low resolution of the flying object in the
video doesn't allow us to clearly see that it is decreasing in size as it
travels down its flight path and perhaps it is this low resolution that
discourages us from further investigation.
In this case it
is much easier for the viewer to rely on a subjective method of analysis rather
than to take an objective stance by utilising straight forward measurement
coupled with a comparative methodology for identifying any changes in
perspective. As a result the flying object appears to fail the perspective
test, but in reality is passes with flying colours as has been clearly
demonstrated in this article.
Conclusion
When an object
behaves in such a fashion as witnessed in the Fireman’s Video it is behaving in
accordance with the laws of perspective as defined in this article. Every
object in an environment behaves in this fashion whether we see it with our own
eyes, or we see it through the medium of film or video.
