|
The downside of recent
camera technology has been the creation of the
nuisance/quasi-illegal class of stalker. Some operate with
shoe
cams
to surreptitiously scope your plumbing. Other perverts operate under
the government umbrella. This latter class use
traffic cams to transfer wealth from you to them.  To my knowledge
neither operate with the victim's permission (has there been a
municipality that first held a voter referendum?). Enough talk.
 It seems that when hit with a laser beam, cameras (any
camera) will
have its vision temporarily impaired. Well, temporary unless you
have one of those jim-dandy lasers that will bring down a ICBM - like
the one we almost had until Obama stopped development.
Whoops. Sidetracked. This guy has done some serious
investigation into this subject, and especially on the cheap.
Below, a few selections. If you're interested in learning more
you can go to How to ZAP a
Camera: Using Lasers to Temporarily Neutralize Camera
Sensors
 |
This cheap laser
pointer emitted an oval-shaped beam (as is often the case) that was
about 2mm by 4mm in diameter at very short distances, and expanded to
over 5cm by 10cm at 100 meters (due to cheap collimating optics). In
medium and bright light, it was difficult to see with an unaided eye.
The obvious solution was to couple the laser to an optical scope and
pre-calibrate them. |
Telescopes and binoculars generally do not have cross-hair reticules
built in, but rifle scopes do. Rifle scopes are available at prices
upwards of $2,000, but like handguns, most of the market appears
targeted at lower-income customers, and cheap rifle scopes can be found
for under $10. All rifle scopes have built-in reticules with some form
of cross-hair or dot at the center, which are internally adjustable
with set screws. The only problem is that, unlike telescopes, rifle
scopes are made to be viewed with the eye several centimeters from the
rear optics, since they are mounted in front of the operator's face.
(This distance is specified as "eye relief," and is typically 2 - 5
inches but is never zero.)
A simple prototype system was built with a $30 mail order 5mw red laser
(635 nm wavelength, which appears much brighter than 670 or 690 nm red)
and a $10 rifle scope with a 4X magnification (Tasco Rimfire, made for
small game hunting). The laser and scope were secured together and the
cross-hair adjusted to center on the laser beam at 100 meters.
|
|
 |
Through the rifle
scope, the glint reflected from the lens was indeed apparent,
particularly when the camera lens was zoomed in. It was easy to
intermittently hit the lens but difficult to maintain aim by hand.
A second prototype expanded in several directions. First, it is
tripod-based, with a precision head allowing independent adjustment of
its 3 axes (Bogen/Manfrotto "Junior Geared Head," complete system costs
around $200). Then, a larger rifle scope was used for a bigger,
brighter image (Tasco World Class 3-9x zoom, $70). Finally, the cheap
laser pointer was replaced with a laser gun sight, which has the same
Class IIIa power rating but much better optics, resulting in a more
circular and collimated beam (Beamshot 1001 for $110). These gun sights
also have adjustment screws to align the beam, durable metal cases, and
many options of mounting hardware. So, for under $400, a rather serious
camera zapper can be assembled. |
|
If either the
camera, or target, is moving, then some form of aiming and dynamic
tracking is required. One solution is to do it ourselves. A third
prototype was built to be small and hand-held for near and medium range
moving cameras
The result was made with a Beamshot 1001 laser gun sight
and a small monocular made for golf range finding (Tasco Golf Scope,
$20), basically a small telescope with a grid-like reticule inside.
Unlike a rifle scope, its eye relief distance is zero, which makes it
comfortable to use hand-held. This new system could fit in a pocket and
was very easy to use. It turns out that precise calibration was not
necessary, since the beam is easily visible in the scope at near and
medium range distances. If one wanted to scare away a news
cameraperson, this system would be ideal.
|
|
I know what some of you
are saying. "But Rodge, how do us girls protect ourselves from this guy ?
Simple.
Insert
this
and go regimental. You're welcome.
|
|
