There are a lot of photos on the web of atomic explosions taken with
Edgerton's "mechanical shutter" camera, and even photos of the device
itself. But, I can't find any web sites that state exactly what kind
of shutter it was. The links that come closest to indicating that
they might describe it turn out to be blank -- i.e., I get the 404
not found message. (Is this Homeland Security in action?) The
troublesome phrase is "mechanical shutter," which I would not apply
to a Pockel (or Kerr) cell device which depends on the imposition of
an electrical field. The lag time between event and exposure (i.e.
10ms, 20ms, etc.) would not be difficult to achieve, even with a
mechanical shutter, it seems to me, but the subsequent exposure times
with the intensity of the nuclear blast would be a challenge. My Q-
clearance lasted only for one summer in 1966, and I didn't have "need
to know" even then, so I can't be more definitive than this.
Roger
Roger Eichhorn
eichhorn@xxxxxx
On 13 Feb 2006, at 19:40, Andrew Davidhazy wrote:
I believe (not positive) that this camera used a Pockels Cell
(solid Kerr cell) shuttering mechanism. All electromagnetic. Angle
of polarization of light passing through a "glass" block was
briefly rotated by an electromagnet so that it would match that of
a second polarizer which was oriented so its plane of polarization
was crossed to that of the first or front polarizer. So, under
normal conditions transmission of the system as very low. When
angles were aligned transmission was better ... but still pretty
low! But when you have a lot of light to start with (nuclear blast)
low transmission of an optical system is generally not a problem.
Now, note that this is off the top of my head and there seems to be
less and less "stuff" there.
cheerio,
andy
Oh ... operator could be a rapper, sure.
How does a Rapatronic camera achieve such short exposures?
And is the operator a Rapper?
Steve
