making a clear lens red

[Tim Hall]

Back when I was selling marine aids to navigation we reckoned the light output of a filament lamp seen through a red (or green) lens was 30% of the light through a clear lens.

 

[Chris S]

Tesco value pudding?

Nothing as classy - it was an Aldi pudding

 

[presta]

[QUOTE 5007025, member: 9609"]I'm more thinking of that moment before dusk when you go under the shade of trees and then you hear someone coming, as its not properly dark it needs to be an intense light and an intense light would be energy hungry, too hungry to leave on for a 4 hour ride.[/QUOTE]
I bought an automatic so that I wouldn't have to choose between stopping to put the light on at dusk or wasting batteries by switching on before I set off. It wastes batteries anyway because it switches on at about 2pm - before I set off.