Test Report No. WCEFP-2-4,
Physics Branch,
Sensitometry Unit 29 Nov
1951
Subject: Evaluation of 35 mm.
Negatives
FACTUAL DATA
1. Four negative frames were
submitted from the Air Technical
Intelligence Center for photographic evaluation by the
Sensitometry
Unit. These negatives were exposed at approximately 2330 CST, 30
Aug.
1951, at Lubbock, Texas. The
camera was the familiar Kodak 35 with coupled range-finder and a
50 mm
(2
inch) f/3.5 Anastor Kodak lens. The Plus X film was exposed for
1/10th
sec
with
lens aperture wide open, presumably with the camera hand-held and
the
film
was processed in Panthermic 777 developer for 15 min. An
interpretation
of
the configuration of spots was requested, in addition to general
sensitometric notes.
2. A preliminary microscopic
examination of the negatives
disclosed the
presence of patterns of spots, the patterns on the four frames
being
generally
similar. Roughly 20 spots were visible on each negative in a flat
"V"
formation.
In 3 negatives the formation consists of two rows, while the
fourth
shows
all spots lined up in a single row. All negatives show evidence of
camera
motion during exposure, since the spots all are similarly blurred
on
the
same negative, and the blur shape is different for each negative.
3. To resolve the formations and
detect internal motion of the
spots,
each negative was examined on a large comparator microscope. The
rectangular coordinates of each spot, relative to a convenient
origin
of coordinates, were read and then plotted on coordinate paper. It
is
emphasized here that the resulting plot is erect, but a mirror
image,
from left to right, of the actual object photographed.
9. Although the image size in Frame
8 is about 2% less than in
Frame 7,
suggesting that the objects are receding from the camera, the
aspect of
the
"V" formation does not correspond to a horizontal "V", travelling
parallel
to the earth's surface unless at an enormous altitude. Such motion
at
conventional
altitudes would require the "V" to flatten, eventually becoming a
straight
line, but the "V" in Frame 8 is a slightly smaller angle than in
Frame
7.
10. The orientation of the "V"
formation is the same on all
negatives.
If the formation did actually pass directly over the camera
station,
all
photographs were taken either before or after, but not both. It is
obvious
that the image would be inverted on two successive negatives if
they
were
taken on an approaching and then a receding slant angle.
11. The pattern of spot brightness
is such as to prove
conclusively
that all 3 frames —5, 7 and 8—were exposed to the same object
pattern
of
spots. However, the relative positions of these spots varies, as
described above.
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