sqflyer

I'm thinking of getting one of those heat rejecting window tinting done on my 8, but when I was researching tinting films, I learned that most of them work on the principle of reflecting IR and UV light. So I'm wondering if the window tinting would make my car easier to target by traffic laser (laser is used extensively where I'm located ). Anyone can offer any advice/comments?

truemagellen

reflective tinting isn't legal in any state anymore...but as for normal tinting that will provide a reduction of heat go for it just check the laws

your screwed anyway with laser so get a laser jammer such as the escort ZR3 or Bel Laserpro and then get whatever tinting you want

I'm getting a laser jammer in the next 2 weeks

sqflyer

Well the window tinting is not reflective to visible light, but rather just the UV and IR which is what causes the heat in the car.

I agree that there's not much you can do about a laser hit. I'm concerned that the laser jammers might not have the coverage if the smart cop targets the windshield, which leads me to the question of whether window tinting might make it easier to target with a laser gun.

StealthTL

iTrader: (1)

You can put any kind of tint on your windows, it will be irrelevant from a 'laser' point of view.

They aim for the headlights, never the windshield.

Try it yourself - face the car 50 metres away with a cheapo laser pointer. Flash it around, you will see where the 'payoff' reflections are.

Headlights = 'kaCHING!'

S

speedweasel

Stealth is right...and also dont forget your front license plate. And as for that laser jammer, the baskcatter from the laser measurement device is keyed to the axis, phase and pulse repetition frequency of the the laser llight pulse. Unless the nice police officer decides to accomodate you by aiming at your jammer, turning the emitter just so and tuning his laser frequency to the exact Doppler shift ratio for 55 MPH above your jammer....you are just SOL and about $350 poorer (plus the ticket cost).

Look on the bright side...the RX-8 does not have reflector type headlights and if you are lucky enough to live in Alabama...no front plate either! Because of that...the police dont use laser. I have never heard my laser detector go off here. Roll Tide!

truemagellen

I'm talking about a laser jammer NOT radar jammer
there is no doppler shift on laser

MazdaManiac

iTrader: (3)

Of course there is (of the FSK, anyway). How do you think they figure out your speed?

In any event, they don't even need a very reflective surface, just a light-colored one.

speedweasel

Laser radars transmit pulsed laser light to measure target range. The time it takes for a laser light pulse to travel (at the speed of light) from the ladar to the target and back is used to compute the distance from the lidar to target and back (distance pulse travels = speed of light x time). Target range from lidar is half of this distance (Range = 0.5 x speed of light x time). The change in target range over time (1/3 second typical) equals target velocity. Laser radar must transmit a minimum of 2 pulses to get at least 2 range measurements at 2 different times to compute speed. In reality laser radars transmit tens to hundreds of pulses per second.

Apertures for lidars are optical focusing devices (lenses, prisms, and/or mirrors) used to collimate laser energy into a narrow beam. Some models use the same aperture for transmit and receive; some use separate apertures (one for transmit and one for receive). Lidars use a semiconductor diode (typically 3 diodes) to generate laser light. Most traffic lidars emit laser light around 904 nm wavelength.

Depending upon the model of the lidar, the receive wavelength must match the transmitted collimated wavelength to stimulate the avalanche photodiode and indicate a received signal. Since an 80mph car will shift reflected light wavelength approximately -0.3 nm...this may cause the jammer wavelength to be rejected at the detector in favor of the transmitted base frequency.

So yes...you need to take doppler shift into account.

truemagellen

doppler shift is the difference in size of wavelength of the radio signal from when it is sent out to when it is received after it bounces off an object

laser simply sends a pulse of light that the time it takes to travel to the car and reflect back is a the simple equation of distance/time=speed

doppler shift as a concept is not used in laser speed acquisition devices

Sputnik

You aren't adding any tint to the windshield, except for that little band up top, correct? It should be a moot point from that perspective.

---jps

truemagellen

extremely good point...you are rarely fired at from the back anyway

but still get a laser jammer/shifter otherwise you are driving blind

sqflyer

Actually, the tinting film has to be applied all around on all windshields and windows (not just the top band). It's to block out the UV and IR light so it has to be on all exposed glass surface. To be honest, I'm wondering if it's a mute point because the drive tunnel and proximity of the engine already radiates so much heat into the cabin after engine shutdown.

On the contrary, here we get targetted from behind A LOT. We're practically sitting ducks from behind. We get lasered from bushes, blind corners, overhead bridges, etc (all from behind).

I drive within "limits" most of the time, but I wanna know how often I get targetted. I'm sure it's a helluvalot...

MazdaManiac

iTrader: (3)

That is exactly what the Doppler shift is.

truemagellen

the laser gun isn't measuring the difference in light frequences instead just light reflected so no doppler

MazdaManiac

iTrader: (3)

It is measuring the shift in the frequency of the pulses. What, exactly, did you think it was measuring about the "light reflected"?

truemagellen

Laser is not at all like radar, so calling it "laser radar" is not correct (i've heard it on this forum before ). Laser (or lidar as it's sometimes called, LIght Detection And Ranging) uses invisible infrared light sent out in pulses. It does not use radio waves or the Doppler shift principle like radar does. It works based on the time-of-flight of a pulse of laser light. The operator aims at your license plate, as an aiming point nothing more.

The computer inside the laser gun measures the time between sent and reflected pulses. It sends out over 400 pulses per second, and an average of those pulses is computed and displayed as speed. Since time is constant and distance is known (laser guns also calculate distance, something police radar can't do), the only variable is your speed.

There are slight variations in the numbers for pulses per second depending on the laser acqusition device.

A company called Lasertech designed the technology to measure distances...it was designed for a ship docking on the international space station...and it is used on an object that is moving a few feet an hour

Lasertech was pressured by insurance companies to modify the technology to compute automatically a distance and time of pulse on a moving vehicle...their company went into bancruptcy because they could not produce accurate results on objects moving at speeds above 20mph

as they were planning the dissolve of their company Geico Insurance (the bastard Gecko commercials...one of the insurance companies that do not provide insurance for those who use radar dectors or laser jammers) bought them out and threw millions of dollars to get the project complete...they did but by the basic rules of physics laser technology is inherently flawed

Sputnik

??? Oh... Singapore. I didn't realize that, sorry. Here in the states it's illegal to tint the windshield (except for Nevada, IIRC, unless that changed). I can tell you from personal experience in places like Texas, New Mexico, and Colorado (the sun is much stronger at higher altitudes), just having the side and rear windows done makes a big difference, so I think it would be worth it for you, even with the heat put out by the engine.
People get lasered from behind here too (and alot of people don't realize it). Front or rear, detection alone is practically worthless. And there are plenty of places to target on your car, and adding tint isn't going to make you any more of a target. Besides, tint that rejects IR and UV doesn't necessarily reflect laser like a mirror, it normally scatters it instead. It's simply designed to not let it pass through.

---jps

truemagellen

laser jammer laser jammer laser jammer laser jammer

did I mention...

army_rx8

if only i wasn't moving back to a state where and form of detector or jammer is illegal Dang Virginia. sniff sniff I would so love to have a jammer / detector. oh well

truemagellen

they are illegal in minnesota too...doesn't stop a stealth installation

truemagellen

well just the laser jammers are illegal...but it is on shaky legal grounds...I'm sure it could be knocked down in court since the statute is so wish washy

azharo

Has anyone tried the the laser vil product? www.laserveil.com

truemagellen

it says it reduces the effectiveness to under 500ft...um in many states (including NJ and TX where this came to a district court level) the max distance you can target a vehicle with laser is 800ft

they say typical targeting distance is over 1200 ft...that is true for RADAR and true for mis-trained law enforcement personal but the reality is if you walk in court and they have taken a reading over about 900-1000 ft you can get it thrown out easy

also people get tagged under 500ft all the time

and do you really want to paint something on your car? what if it yellows over time? what if it waxing makes it inefffective

save the $90 and use it towards a laser jammer/shifter...unfortunately that is where things are nowadays

azharo

You make your points. That is why I asked. Just to get feedback. What is a good laser jammer then? Would it drive my V1 laser detector bezerk?

truemagellen

did I sound volatile? sorry I was trying to be informative...instead I sounded smart *** like

the light that is sent from the jammers is sent out to the front and back of the car...unless you have the light relfect of another object and back to the v1 you should be fine...it will rarely happend

good jammers include: escort zr3. bel laserpro (similar to zr3 since bel bought out escort), and I've heard the blinder series is good to but super expensive (they sell them in BMW dealerships around here)

good luck