What products or technologies are available to prevent photo radar
from taking a picture of a license plate, and is commercial available
as a product (and not listed below)?

I am aware of the common ones such as radar detectors, radar jammers,
"photostopper" sprays, and license plate covers, and am not
considering those (I explain why below). I am looking more into
something that is more "active", such as an "anti-flash" or similar,
that would not operate normally to obscure the license plate, but
would obscure or make the plate unclear only in an actual photo.

The reason this question is posed is because all the commonly
available solutions are not effective after actual testing.

1) Radar detectors - do not provide sufficient warning time against
photo radars, since they point to the rear of the car and not the
front, and do not actively stop the photo being taken anyway.

2) Radar jammers - illegal almost anywhere, not known to work on Ka
band radar, so this is not considered.

3) Sprays - do not work. I have purchased 5 different types, such as
photoblocker, photostopper, photofog, and others with similar purpose.
None have worked after being tested on 3 different cars in different
situations. Most make the plate glossy/foggy, but do nothing to
prevent or obscure a photo being taken.

4) Covers - While the covers partially work, they are also highly
visible and obscure the license plate even when a photo is not being
taken. Since it is usually illegal to obscure a license plate in such
a way and is also very visible to the naked eye from an angle, this is
not considered.

Therefore, I am looking for something that might be similar to an
anti-flash of some sort, or something that can detect the flash and do
something against it or  only obscure the license plate at that time,
and not obscure it all the time to the naked eye.

It would be best to have a product that is commercially available for
purchase, although I may consider a product that needs some assembly
or work to make/use, but not built from scratch.

---

Clarification of Question by whoami-ga on 28 Dec 2004 11:04 PST

Even if it is not a product widely availabe, and possible even if only
you know how to make it, then that is fine too, as I'd be interested
in buying it off you (provided you explain how it works!)

---

Clarification of Question by whoami-ga on 29 Dec 2004 12:48 PST

I've raised the price... if anyone knows of a product or can BUILD the
said product themselves, you will be awarded.

---

Clarification of Question by whoami-ga on 03 Jan 2005 07:12 PST

Raising the bar again... $45.

Perhaps no one knows of or how to build this?

On a purely intellectual basis, I have wondered about building a
foolproof system which can?t be photographed.

Build a three zoned kerr-cell which is laid on top of the licence
plate. In sequence, switch the cells at say 100 Hz. The eye wouldn?t
easily see the rapid obscuring but a camera would record only one
third of the number. Even two camera systems would only ever see a
maximum of two thirds of the number. The plate would of course be
slightly dimmed but not markedly so.

But since you don?t want to build from scratch, a design exercise of course.

Best

This sounds like an interesting idea guzzi. Do you have the
engineering or tech knowledge to make this work?

Purely intellectually ;-)

I have the wherewithal to explore -- not time though. Traditionally,
Kerr cells are quite thick (using nitrobenzene) so probably need
research on other liquids for thin plates. Maybe upping the field
would work.

Reason I suggested Kerr (another brilliant Scotsman) is that LCDs are
a bit slow to turn off. Welding goggles (search for ?auto darkening
welding" "liquid crystal") could possibly be speeded up. Certainly in
your application, where contrast ratio specs can be relaxed and a grid
of thin wires wouldn?t matter, much faster shutters could be made. To
compensate for slight darkening, the plate could be back illuminated.

Whatever though, the zoning system should work, especially if
synchronised to the twin camera (or photo) delay. One second?

Someone could make a lot of money out of this one I guess.

Best

I am not a technical person but would like to know how these "anti-phots
radar products" work. Should some one tell me without using too much terminology.
Ijaz Ahmad

Waystland-ga : you obviously did NOT READ MY QUESTION. It said:

3) Sprays - do not work. I have purchased 5 different types, such as
photoblocker, photostopper, photofog, and others with similar purpose.
None have worked after being tested on 3 different cars in different
situations. Most make the plate glossy/foggy, but do nothing to
prevent or obscure a photo being taken.

Please do not peddle stuff that does not work. Thank you.

sucks to be you,
because they do work, I used it and still do.
did you try to take teh picture your self?
then post the pictures.

you want the  secret to beat photoradar?

Dont Speed!

Sure, the following are not sales sites but people who actually tried
it and found it does not work:

http://msgboard.snopes.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=20;t=000472;p=1

http://www.museumofhoaxes.com/hoax/weblog/comments/1602/
"The stuff is crap. Channel 12 out of Portland, OR did an
investigative piece on it recently. They sprayed a license plate with
it and could easily see and photograph the wording on the plate. Then
they went further: They actually found the guy selling the stuff and
he admitted, on camera, that the stuff doesn't work. He conceded that
it was "for suckers." This is not second-hand info; I saw the story
myself--twice--on Channel 12 (KPTV). Their website, KPTV.com, may well
have the story on it.
Posted by crankymediaguy  on  Wed Dec 08, 2004  at  05:38 AM"

Plus I have a can left over... about half full... my friends already
tried it and it didn't work for them, and i'd be willing to ship the
can to someone at shipping cost to them. Its useless anyway.

yah don't speed, cheapest way wihtout being busted for covering up
your plate is the spray.what tests did you do?