white light VS yellow light

[lester]

Why do Chinese cities prefer yellow street lamps rather than white ones? White light looks more bright and glorious. What do you think?

Beijing

Guangzhou

Chongqing

Shanghai



Tokyo

[bonnie ip]

Why do Chinese cities prefer yellow street lamps rather than white ones?
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How did you notice that ?

[Huhu]

Most cities in North America use "yellow" street lights. I think it's because it saves energy and is less eye-piercing for drivers (safety issue).

[no1gizmo]

hm.... yellow looks more warm, white more cold....

Interesting question!!

[lester]

Originally Posted by bonnie ip

Why do Chinese cities prefer yellow street lamps rather than white ones?
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How did you notice that ?

Most Chinese city photos do prove

Originally Posted by Huhu

Most cities in North America use "yellow" street lights. I think it's because it saves energy and is less eye-piercing for drivers (safety issue).

I think energy saving light bulbs produce soft-white lights.?

Originally Posted by Huhu

less eye-piercing for drivers (safety issue).

Think about your car headlight, white is much clear

Originally Posted by no1gizmo

hm.... yellow looks more warm, white more cold....

Interesting question!!

good to use white in summer

[Huhu]

Originally Posted by lester

I think energy saving light bulbs produce soft-white lights.?

You're thinking interior compact florescent bulbs versus incandescent bulbs. Streetlights are sodium vapour lamps not incandescent.

Originally Posted by lester

Think about your car headlight, white is much clear

Actually headlights are slightly yellow or gold in colour I believe. Some people install intense white headlights for 'good looks' but that's actually illegal and will get you a ticket.

Okay, I've done some more research. It appears that yellow lights are produced from sodium vapour lamps, and they are easier to filter out in terms of light pollution (there is only one wavelength). White versions of such lamps are used but are more expensive to manufacture and have shorter lifespans as well as lower efficiency. On the other hand white lights seem to improve peripheral vision and reaction time in terms of road hazards, however powerful white lights are less desirable for car headlights because of the glare caused for oncoming drivers. In fact highways have very few streetlights because they cause drivers to lose night vision and makes it difficult to distinguish oncoming headlights (easier to see a light on a black background than a gray background).

I've found this explanation for the different kinds of lights used:

High Pressure Sodium Lamps: These lamps provide a golden colour. They are used where a more natural colour is required.

Low Pressure Sodium Lamps: The majority of lamps are of this type. It is the most efficient in converting electricity to light and produces the familiar orange colour.

Compact Metal Halide: This type produces a white light giving good colour rendering and is useful in town centres and conservation areas.

Compact Fluorescent Lamps: These lamps are used to illuminate traffic signs and the advent of higher wattage versions is finding increasing use for street lighting using the advantageous white light.

In conclusion, yellow lights are more energy efficient and better for the natural environment. White light provides better contrast for road hazards but can reduce driver's night vision and the visibility of headlights.

IMO selecting city streetlights should be determined by safety, conservation, and environmental protection; in that order. Aesthetics come after.

[lester]

Thank you for your research Huhu its clear to me now

[staff]

Haha, in the photos shown in the original post it is a matter of white balance used in the camera. It has nothing to do with the colour of the actual street lights.

Although, China might have more yellow-ish lights than Japan for example, I don't know.

[bobdikl]

Originally Posted by staff

Haha, in the photos shown in the original post it is a matter of white balance used in the camera. It has nothing to do with the colour of the actual street lights.

Although, China might have more yellow-ish lights than Japan for example, I don't know.

Go ask the danes... scandinavian are the masters of lighting and lamp design.

[rajhdfgd]

Originally Posted by staff

Haha, in the photos shown in the original post it is a matter of white balance used in the camera. It has nothing to do with the colour of the actual street lights.

Although, China might have more yellow-ish lights than Japan for example, I don't know.

great news, i love my seed upgrade.

[Scion]

I like yellow street lights. Feels classier than white.

[z0rg]

I prefer white, looks more sophisticated imo.

[drunkenmunkey888]

Very true, if you take a look at pictures of NYC, you'll notice that it uses yellow lights too.

[Sabanban]

That is a science question. Yellow light is often preferred because human eye is most sensitive to yellow light. Therefore, using yellow street light is most energy efficient. Yellow street light are generally from sodium lamp.