Lets end this now.
I have just called my mate (lets refer to him as Al Knacker of The Yard) who is in the official 'know'.
The older cameras still flash. These are either big tall vertical square boxes or smaller square boxes with 2 lenses one above the other. They use good old fashioned X or K band radar.
There are some new, smaller box type radar units on some of the minor roads, which are painted white, instead of grey and still have the twin vertical lens configuration. These are newer technology, but they still flash.
There are one or two prototype units on test. These look like little square dustbins, are painted cream and only have a single hole in the front. Inside are 2 rangefinder lenses and they do flash but you cannot see it! They operate on doppler infra red principle and will record your speed day or night as well as taking an infra red digital image of your number plate.
The latest and greatest units everyone is talking about are the German built units that look like a big stripey shiny pole. These are the mutts nuts when it comes to relieving you and I of our hard earned cash and sticking little black marks on your license! They use the infra-red technology and also feature a panning head unit! Bloody sneaky! You can slow down before the camera, then speed up afterwards...and it'll have you up the *rse! THEY DO NOT FLASH!
The portable roadside units are still circa 1850 and use a camera where the guy hides under a big black cloth and pulls the cover off the shutter. But they can still have you!
We're all dooomed!
Knight