Will lights be limited?

[Davidc]

Aye, I think that is how it works. I'm don't have any lumens figures handy, but the low setting is 10 lux and the high setting is 40 lux (which I think is about 200 lumen). I assume the high setting is for offroad?!?

Seems strange, as the CYOs are Germany legal and they are 40 and 60 lux. 10 is more or less what filament lights could manage.

BTW lux and lumens don't measure the same thing so you can't convert simply. You need to know the area being illuminated.

 

[magnatom]

Seems strange, as the CYOs are Germany legal and they are 40 and 60 lux. 10 is more or less what filament lights could manage.

BTW lux and lumens don't measure the same thing so you can't convert simply. You need to know the area being illuminated.

I've looked at the blurb and yes the low level is at the limit. The lux was measured at 10m from the light.

Oh and I know about the differences between lux and lumen. I am a physicist! (although in a completely different area!)

 

[Bollo]

I've looked at the blurb and yes the low level is at the limit. The lux was measured at 10m from the light.

Oh and I know about the differences between lux and lumen. I am a physicist! (although in a completely different area!)

You're a magnet-waving fop!

Another (lapsed) physicist here who spent many a happy year developing radiation transport models for gamma-ray detectors. Lucky me.

 

[sunnyjim]

You're a magnet-waving fop!

Another (lapsed) physicist here who spent many a happy year developing radiation transport models for gamma-ray detectors.  Lucky me.  

Us traindrivinfridgerepairinheatinventinplumbinsparkyindirtyfingernailin engineers & grubby quantum mechanics  can only gaze with open mouthed admiration..

 

[ufkacbln]

I've looked at the blurb and yes the low level is at the limit. The lux was measured at 10m from the light.

Oh and I know about the differences between lux and lumen. I am a physicist! (although in a completely different area!)

Fizzy Cyst!

 

[ufkacbln]

You're a magnet-waving fop!

Another (lapsed) physicist here who spent many a happy year developing radiation transport models for gamma-ray detectors. Lucky me.

Get some Mans' radiation!

F[sup]18[/sup] rules!

 

[Bollo]

511keV colinear photons kick ass! Twas PET detectors that I did sums on. Also did a lot of image reconstruction stuff. Fabulously interesting, but all the real detector research was happening in Japan and the States, so I bailed out in the mid 90s.

 

[sunnyjim]

511keV colinear photons kick ass! ...

Maybe so. - But there's buggerall emission at them pissy liddle wavelengths down at  2046K where all them candles & lumens is.  Co-linear photons s'no problem- it's all them  little boggers wandering off to the right dazzling the motoring populace.

 

[Trumpettom001]

yes but can you explain the significance of e=mc^2?

 

[sunnyjim]

yes but can you explain the significance of e=mc^2?

Hell I can't even explain the significance of F=Ma but it seems to work if I pedal hard enough & lay off the pies.

 

[Davidc]

Oh and I know about the differences between lux and lumen. I am a physicist! (although in a completely different area!)

I'll apologise and shut up then!

(So was I once but it didn't pay the bills well enough.)

 

[Shut Up Legs]

Maybe I misunderstood your post. I assumed that you believed that oncoming drivers flashed you because of your lights. If it's for some other reason, then not relevant to this thread.

Yes, you misunderstood my post, and it is relevant to this thread.

Dazzling (=temporarily blinding) someone isn't justified just because someone else once dazzled you. If they are dazzled, they may not even know what type of bike/vehicle you are.

How on earth did you draw that conclusion? It certainly wasn't from anything I said. I would never deliberately "dazzle" anyone with my headlights just because they did it to me, so please stop misquoting me.

The supernova website gives no data on beam pattern or intensity, so it's impossible to say what the off-axis intensity of your light is without measuring it, but if not controlled like a car headlamp, it's probably a lot brighter than a dipped beam.

I've seen it from the front, and also in photos, and I've seen enough to tell me its brightness is not too much. If you also have first-hand observations, feel free to share them. Secondly, I clearly stated in my previous post that I had it dipped to illuminate the road in front of me, so you must have missed that bit.

A simple way of checking whether it's too bright off-axis for oncoming vehicles would be to cycle along a dark & not too busy road & see if many oncoming drivers flash at you - that would be a good indicator that it needs adjusting. A simple baffle taped to one side might help.

500lm is comparable to a car headlamp, so definitely not 'only'. You need to be carefull to avoid illuminating the other side of the road, just as car headlamp optics are designed to do. It doesn't need much intensity to dazzle someone at night, and the effect can last for some time afterwards.

Just for the record, I knew all the above (except for the bit about "comparable to a car headlamp", which is incorrect), but thanks for sharing it anyway. Car headlamps are typically a lot more than 500lm, more like 700 or 1000+. I don't want to rehash yet another bike vs. car headlamp discussion, though - if you're interested in the details, do an internet search.

 

[sunnyjim]

Yes, you misunderstood my post, and it is relevant to this thread.


How on earth did you draw that conclusion? It certainly wasn't from anything I said. I would never deliberately "dazzle" anyone with my headlights just because they did it to me, so please stop misquoting me.

I cetainly didn't misquote you - although I may have misunderstood. Some of your statements appear to contradict the original comment that  (QUOTE) I've had motorists flash their lights at me a few times, and I suspect it's because of this light. (/QUOTE), which is where I jumped in.

Whatever, we can agree that motorists who don't dip for cyclists or other motorists are a pain.


(QUOTE)
Just for the record, I knew all the above (except for the bit about "comparable to a car headlamp", which is incorrect), but thanks for sharing it anyway. Car headlamps are typically a lot more than 500lm, more like 700 or 1000+. I don't want to rehash yet another bike vs. car headlamp discussion, though - if you're interested in the details, do an internet search.

I can't be expected to spend all day checking & correcting the internet...

The apparent difference is  probably  that the numbers advertised for bulb output aren't what's actually put on the road. A standard H4 bulb has a specified minimum light power from the dip beam filament of 1000lm. (ref BS-EN60809)
After allowances for manufacturing tolerances & ageing, than could be as low as 750lm. Headlamp optical efficiency is unlikely reach 50%, and may be as low as 30 %. Losses include collection efficiency, reflector, scattering in complex beam shaping optics, and transmission through front glass/cover, not to mention general muck on the lens.
Hence 500lm on the road wouldn't be abnormally low for an ordinary car lamp. Yes there are higher power bulbs available, and  some probably do put out 1000lm from the headlamp.

Your bike lamp is sold as a complete unit, so a quoted 500lm should mean 500lm on the road.

That's why I said 'comparable' - because it is.

 

[Shut Up Legs]

Agreed. Motorists who don't dip their lights are a pain. As for the rest - the problem with internet forums is how easy it is to misunderstand another poster, so if I wasn't clear enough, then sorry about that.

As for whether or not you agree with the rest of my responses - I think we've discussed this enough for now - agreed?

 

[Mark82]

i once had a ticking off from a copper for having them set to high... he told me they dazzled him as he drove the other way..??? ( as above what about these land rovers with bright lights....nothing )they wasnt super power but enough to cause him to moan about it,