Is the best rear light, a front light.

[KM2]

Because a normal rear light doesn't give much indication of what you are, would a forward facing front light mounted on the back of whatever rear bag you have, give a better chance of survival whilst commuting? Especially it pointing at the reflective bits of a good commuter jacket.

[tatanab]

Sounds similar to the front light that also illuminates the front of the rider by a wash of light backwards. This was on the market only a year or so ago and may still be so. Why shine lights onto reflective patches? Isn't that what motor vehicle lights will do much more effectively?

[meic]

The things that are a danger to you have great big headlights on the front, which would make the added light pretty inconsequential.
The reflective material would bounce the light from your lamp back towards the lamp, not to the eyes of the danger sources. The reflectives are very directional.

[thirdcrank]

Meic is right about the reflectives. IME, it's the sort of thing that would attract unwelcome attention from the occupants of overtaking cars, especially during the night. I suppose that if this system became widely used, it might attract less unwelcome attention.......

[KM2]

"
"The reflective material would bounce the light from your lamp back towards the lamp, not to the eyes of the danger sources. The reflectives are very directional."

Working on that principle, the reflected car light would never enter the drivers eyes. Unless the reflective are not as directional as imagined.

[thirdcrank]

You can try this for yourself. Hang your reflective garment at one end of a darkened room, the longer the better, and standing as far away as possible, hold a torch at the side of your forehead and shine it on your reflective garment. Then extend your arm and you will see a reduction in the reflected light. At "on the road" distances, a car driver's sightline is just above the beam of their headlights, so the angle of reflection is very acute.

Alternatively, do the darkened room test with a torch shining up from below and it will demonstrate what meic and I are saying.

[KM2]

I was thinking that any chance of illuminating the object beyond the normal dipped headlight distance, would give drivers more time to react.

[Brucey]

IIRC the semi-angle for best reflection from retroreflectors is between about one degree and three degrees, depending on the type in use (broadly prismatic moulded plastic or glass beads respectively ). This means that if the light source and the viewer subtend the same angle to the reflector (plus or minus that semi-angle) then the viewer will see a bright reflection. This means that (for example) sat in an ordinary passenger car anything retroflective reflects with optimum efficiency back towards a driver provided it is over 25 metres away. Closer than that and you should be in range of the headlights anyway. IIRC glass beads reflect slightly less efficiently but can be seen over a bigger range of angles.

It is an interesting idea to have a fixed light and a retroreflective target surface; I suspect that most viewers would see something like a 'narrow ring' of reflected light from the target (surrounding the illuminating light in some cases) and from many angles they would see nothing; eg as soon as an incident light strikes a prismatic reflector at 45 degrees or more, the reflector stops working altogether.

If you get a chance to try your scheme and compare it with the same target illuminated by (say) a dipped beam, so that the target is above the 'cutoff' (which means there is still some light rather than no light BTW) I'd be interested to see comparative photos. FWIW I think photos may only be compared if they are exposed in the same way, i.e. with the same f-stop and shutter speed etc. Not all modern cameras will allow this type of exposure.

cheers

[thirdcrank]

At closer distances, the height of the reflective makes a big difference. Seen from a car, the feet of a jogger with reflectives on their trainers will be highly visible when reflectives higher up are virtually invisible. This is because of the very acute angle of reflection.

[KM2]

Perhaps getting bogged down in reflective strip, whereas I would see this as a way of illuminating the cyclist, outside the normal range of car driver vision. It simply gives shape to an object, as opposed to a small but possibly bright light in the distance.


I can remember a suit made of,I think, glass beads stuck to the garment. The idea was to give shape to the cyclist so that drivers wouldn't waste life saving time trying to interpret what is ahead.

[tatanab]

I would see this as a way of illuminating the cyclist.

I suspect it would have to be rather bright to show the shape of the rider. This would the cast a shadow ahead, just like riding in company when the rider behind has a hyper light.

[thirdcrank]

Over the years, we've had several threads with links to non-conventional lighting systems for making riders more conspicuous ie not depending on the usual front and rear lights. IIRC, we've had at least one where a light under the bike shone upwards to light up the bike and rider.

PS tatanab makes an excellent point

[reohn2]

I've found the only thing that's cut down on close passes to a minimum is to make me look wider than I actually am.
The widest part of a rider is the elbows so I fitted a bright rear light(Smart 1watt) on a band(elasticated trouser straps are idea) on the upper outside arm just above the elbow as an addition to a rear light fitted to the bike.

[mattsccm]

Two lights on a trike makes it look wide. ( yes I know it is but you get my drift) why not one of those flag things that stick out? Easier than slapping something on the elbow.

[reohn2]

Two lights on a trike makes it look wide. ( yes I know it is but you get my drift) why not one of those flag things that stick out? Easier than slapping something on the elbow.

The other thing about a rear light on the elbow is that it's at the motorists eye level.