In message , Graeme
writes

NOT TRUE.

2 standard colour 35mm exposures using flash illumination. Nothing infrared
involved with Gatsos.

So are websites such as http://www.termsys.demon.co.uk/gatso.htm wrong
when they claim ...

The photographs taken will be both normal and infra-red. (The
infra-red will 'see' your registration mark when the vehicle is
caked in dirt.) Also, to collect the proof, two photographs are
taken in quick succession, so that the distance travelled can be
seen.

And http://www.benlovejoy.com/speedtrapdetectors.html ... with its
picture of "A forward-facing infra-red Gatso hidden behind a sign"

Gatsometer's own site claims that they make GATSOs "with optional
infra-red flash", but I have no idea if these are used in the UK.

Other systems using Automatic Number Plate Reading Video cameras (such as
SPECS average speed enforcement system) use infrared illumination. Gatso
doesn't.

I believe the Truvelo system also uses I-R.

Basically, if I-R is being used at all, and it certainly appears to be,
then I cannot see how a reflective spray varnish will help to avoid it.

--
Paul Terry