ur
the
on-
en
Ain
on-
gle
til
uld
sti-
ind
'an
ity
the
een
ues
OF
nts
rial
ove
off
hat
ime
'ess
0g-
ted
jy to-
nic
jy to-
tics
for
for
zht,
ent
phy
ots,
ing
r of
oto-
lese
vth,
can
PHOTO INTERPRETATION PICTURE, COLWELL 99
scarcely be discerned by a ground observer; furthermore they are far more readily seen
on this photography than on conventional high altitude photography.
Colwell (1956) has demonstrated that for certain types of photo interpretation it is
desirable to obtain either still or motion picture photography from low altitudes and
Fig.6. An example of the image enhancement made possible by LogEtronic
printing (right photo) in contrast with conventional printing (left photo)
from the same negative. For further details see article by Craig (1955).
(Photo courtesy LogEtronics, Inc.)
from precisely situated camera stations. When attempting to obtain such photography
from fixed wing aircraft, he found that their relatively high rate of travel and limited
maneuverability posed serious problems in (1) framing the target properly, (2) photo-
graphing it from the correct camera stations, (3) minimizing image blur, and (4) ob-
taining sufficient overlap to permit either stereoscopic or motion-picture viewing of the
photo images. He found that each of these problems could readily be overcome through
employment of a helicopter, or in some instances a dirigible, as the aerial camera plat-
form. The main advantage of the helicopter was its greater maneuverability, permitting
wr