DOW-UAP-D102: Project Blue Book File on Tremonton Film, Utah, 1952

·code 01/Jrtrw/lbh
J12
UNCLASSIFIED
Serial:
Subj: Interpretation o:f Movies of Unidenti.f'ied Objects;
progress report on
b. Densitometric teets:
Densitometric data were obtained with a Densichron, Mod.el 2150
manufactured b : - the Welch Scienti.f'ic Company. The 'D,nsichron has a scale
range or 0-3 . The procedure was to project each f'rame at approximately
22 times magnification onto a finely-grained-glass screen. The back
ground. (sky) was then measured at several places and the density set to
3.0 (variations in background densities were in the order of 0.02 and
were regarded as uniform) . A set of three readings were made of each
of seven objects in Part I, and of the single object in Part III of
the Utah Film. Readings were made o:f the entire Montana film.
Enclosure (6a and 8b) are graphs ot the density readings
obtained of the two lower groups of objects in frames l-129 of the
Utah film. Enclosure (9) is a density graph of the single object (94
frames) in Part III. Enclosure {10) is a graph where six successive
Densichron readings were averaged and advanced one reading each deter
minant.
Of the M:>ntana film, densities were plotted as above and are
enclosures (ll) and (12).
The results of' the density readings may be questioned in that
these objects varied in size so that at the minimum sizes the densichron
probe was measuring the entire object, and at the maximum size the probe
was measuring only a portion of the objects . Because of this situation
only the largest readings obtained b scanning the objects were uaed.
It is understood that normal procedure would be to read the entire object.
This was illlpossible with the equipment on hand.
In addition the film, with which this investigation was conducted,
is a duplicate of a copy. Thie raises the question as to whether the
central portion of the objects were burnt out during the duplication
processing. Density readings were made to compare the clear areas and
the objects. It was :found that the minimum difference is 0.4. This
indicates that relative luminosity may still be obtained with the pro
cedure used. Concurrent with the density readings, relative sizes of
the objects were noted in order to correlate distance and luminosity.
Enclosure (13) is a plot of the same object wherein the relationship of
distance and luminosity can be detected in Utah .film. •
l>OWNGRADED AT S YRAR ~'.J,...T"T>Y n .-n.
DEC.LASS - ~ L"i"''
3 Answers to Questions IFIED AFTER 12 YEARS.
• • DOD DIR 5200.10
Answers keyed to the questions contained in enclosure {7) of
reference {a) are hereb:,- presented. They supercede those contained in
reference (c) and present the final analysis as requested.
UNCLASSIFIED