ay
Deo lg-nm Fastax coneras, incorporating actoamatic expeosere ccetrsl, vere
used.
These cameras, cperated at 2X0 frames ger second, Save a tila capacity
of ~OO fence.
re ia characteristic of
approzisate:y 100 usec.
this sechanisa to orlese acd folisn alrer
The initial iiiter setcing fe made for aderuate exe
posure S:rizng the firse 100 psec.
Additional ta evaluation of the exposure
contre] systea, resulticg fila recores sere interded to provice early-tise radi:
versus-Ltize data as well as documeatazy coverage.
11.3.4
Mitchell Cameras
.
Three Mitchell 35-cam high-speed sction picture caseras were located at
the camera staticn on Johnston Island.
Anscochrese color fila was used.
Gen-
erally, eaphasis was cn radii versus time and later tice phenomena, in addition
to qualitative or doc.mentary coverage.
These caceras afforded a wide field of
view fapproxicately 36 by 48 degrees).
Foz che Crenge event, three off-site Mitchell 35-com morion picture cazeras
were edded.
Two caseras were located at French Frigate Shoals and one vas
placed aboard the USS Boxer.
scale phenocena.
Prine interest was in very late-tizne, large-
Here also, Anscochrese color fila was used.
These cameras
were inteoded to provide qualitative data only.
11.3.5
Ballistic Plate Cameras
Two ballistic plate cameras, especially designed for obtaining positioa-
ing data on 10+ by l2-icch sensitized glass plates were used.
Four sets of
fiducial carks were exposed on the plate for accurate and repeatable reference.
Lens focal length on these cameras is 12 inches.
To assure precise position-
ing, the ballistic camera incorporates a sount for lccatisn of a theodolite
directly over the nodal point of the lens.
One casera vas located at the west
end of Joimston Island and the second was established on Sand Island to obtain
as long a base leg as po:sible.
An explosive capping shutter was designed to close while the mechanical
smtter was still in its ouch slower process of closing.
Exploding che charge
was acccoplisked by a photocell-controlled circuit triggered by the first light
Qs
~~
&
Effective closing time was approxizately 250 usec.
SX)
of the test detonation.