JT> You may be able to get away with it at night, but during the
 JT> day, the flash will have little or no effect on the exposure of
 JT> the photo.

 BL> (grin) A photograph uses light reflected from the number plate,
 BL> and day or night this would be overwhelmed by the intense
 BL> flash.

 JT> Not unless it was a *direct* reflection, this is the very
 JT> reason they banned those "bubble" rego plate covers.

  That's the idea of the slave flash mounted on the car; to respond
fast enough to be similar to a direct reflection, and fog the film.

 BL> My idea was to install a "reversing" light and build the flash
 BL> into that (along with the reversing lamp). If the cops suspect,
 BL> simply turn it off.

 JT> Oh, I'm sure if they notice that fucking bright flash coming
 JT> from the rear of your car they will check it out, especially if
 JT> it was a false trigger. 

  How do they check it out? I just turn off the flash function, and
they can flash my reversing light as much as they like. My story is
that it mush have been a reflection or something. Who knows? A
reversing light is not illegal.

  But in any case, the speed camera is a fixed installation. No one
chases the motorist. The cop can't just jump in his car and leave the
equipment. So if they flash me as I go past and my car flashes back...
what do they do? They don't have my number and if they chase me I'll
have a five-minute start by then. I'll have two minutes even if the
cop is mobile... and by then I've turned the flash function off. My
guess is that the cop probably wouldnlt even notice, and if he did
he's just shrug and let his camera photograph the next car in line.

 BL> Yes... this was what stopped me: high-beam from other cars at
 BL> night, and sunlight reflections during the day. My idea was to
 BL> put the sensor down a tube with a lens, to narrow the field of
 BL> view off to the side where the cops would be lurking... but I
 BL> never tried it.

 JT> You would have to rely on them being in a certain position
 JT> though. Not always reliable, especially on a multi-lane road
 JT> where position may change too far off for that technique to
 JT> work.

  My idea was to have the sensor angled away from directly behind, to
avoid high beam and reflection off other cars. It's wouldn't be hard
to test: just set it up and count the hits driving around.

 BL> My fallback idea was black and yellow PVC tape to change the
 BL> number. I actually did this, and it's virtually undetectable
 BL> unless they actually look. 

 JT> Until they stop you for something else, and check your plate
 JT> out. 

  That's the problem, but in my case the oddds are pretty good. In 40
years of driving I've only been pulled over 4 times. If you were
involved in an accident, you could simply strip off the tape.

 BL> That won't work. They lock to the fastest return in a set
 BL> range, and you's have to be phase/frequency locked to their
 BL> signal or they'd just ignore it.

 JT> No, the idea is that your laser is always on. Phases don't make
 JT> for much when using the doppler effect

  Lasers don't use doppler...

 JT> Oh, have you ever looked into a five milliwatt laser? You have?
 JT> What, it doesn't seem so bright? That's because you're blind.

  Bullshit. I don't know what you call a tight-beam laser, but the
ones they use for ranging measurements focus to about 2mm diameter. To
damage tissue in the eye you need 10 kw/sq.m, and that's 125mW.

 JT> My question is, is *that* bright enough to cause even a
 JT> possible problem?

  No. It's called engineering.

Regards,
Bob
___ Blue Wave/QWK v2.12
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