Lights on prewar British tanks

Originally posted by Richard Farrant
Hmmm. not entirely convinced with that as both lights are side by side over the rear number plate and blue would be just as visible as red. But maybe that was why they turned to a white light shining on white down below.

Richard

Maybe, however, the eye is most sensitive in the low end of the spectrum which is red (700nm) and at its least at the high freq end which is blue (390nm). A 3W bulb behind a dark blue lens would be quite feeble and probably inconspicuous at any distance.

R.