On 08/06/2018 10:43, Dave Plowman (News) wrote:
In article ,
dennis@home wrote:
Its just a case of getting the exposure correct.
To do so may be impossible with some cameras.

It's not. Having the light source - in this case infra-red - beside the
lens means it reflects straight back into the lens.


Which is the point of retroflective number plates. AIUI, the problem is
avoiding other light sources from reflecting off the outer face of the
plate. That is why they fitted a filter matched to the wavelength of the
IR emitters to the number plate camera on my industrial estate.

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Colin Bignell