Like many things in life, this is one of those topics that makes you realise how little you understand about it!
Exactly what does 10, 20, 50% brighter look like? Do LEDs look brighter because they’re whiter? Does a whiter light actually improve night vision, or does it just ‘look’ brighter? Etc.
There’s no question they look brighter and they’re MUCH better at making you MUCH more visible to half asleep / distracted car drivers, day or night, so they’re worth it for that alone. I don’t know if you guys have noticed, but these days some bicycle lights are brighter than some older motorcycles lights, with super bright lights everywhere, dim lights make you harder for car drivers to spot, especially in busy cities.
But whether or not they improve the riders vision at night, and if so, by how much, I really don’t know yet, my assumption at the moment is they’re quite a lot better, but I gotta get out and see.
Kommando, I think you’re right about dipping the beam a tad, that’s something I’ll experiment with.
Nigel - I tried to write up all my old and somewhat stale photographic knowledge, on how light works, but I deleted it as it was too complex and poorly written.
Exactly what does 10, 20, 50% brighter look like?
Lumens are how light is measured, the total quantity of visible light emitted by a source per unit of time.
The lumen can be thought of casually as a measure of the total "amount" of visible light in some defined beam or angle, or emitted from some source. The number of candelas or lumens from a source also depends on its spectrum, via the nominal response of the human eye.
A light is x% "brighter" because it gives of x% more lumens.
Second, we cant talk about Watts - like we have always done for incandescent or halogen bulbs. Look at this chart to see how watts affect output (lumens) in differing bulb types. This is from home-type bulbs, but the principle applies.
Do LEDs look brighter because they’re whiter? Does a whiter light actually improve night vision, or does it just ‘look’ brighter?
Perception is how you deal with the objective of lumens and color spectrum in your eyes/mind. It depends on the environment, your eyes, and color. But the simple answer to your question is Yes.
"White" light from LED or HID lights is actually more balanced and thus more blue than incandescent/halogen light (yellow) or sodium street lights (orange). Blue light boosts attention, reaction times, and mood and can disrupt your circadian rhythms (sleep patterns) by 1-3 hours with nighttime use (which is why phones and tablets are bad for sleep before bed).
Studies have shown that people perceive an orange-lit street as darker than a white-lit street, even when identical levels of luminance are provided. It’s also been shown that white light
doubles a driver’s peripheral vision and reduces their braking times by
25 per cent when compared to sodium orange.
Read this - a simple two minute read that should help you understand the basics a bit more.
https://blog.amerlux.com/4-things-architects-should-know-about-lumens-vs-perceived-brightness/
