Kelvin

[Yoda]

I'm considering putting some HIDs into the pair of Hella Micro DE's that are used as auxillary lights.

But I'll confess to being a tad confused over what colour temperature would give the maximum amount of light.

Searching the boards would indicate that 6,000K is the weapon of choice, however the various bulb specifications would appear to indicate that maximum lumens are at around 4,500K.

What's what in the real world of commuting down country lanes in the rain with lots of glare from headlights coming the other way reflecting off the wet surface? The Micro DE's have helped immensely, but I want to put even more light down to counter every bugger else's HIDs!

 

[Bigtwin]

Well I have a 6K one and it's like daylight - I was wewl chuffed innit. Not tried any others, but I'd get the 6k again no question.

 

[Flipfly]

I use a 4700 and it is less blue than 6000k but it does put out slightly more lummens. Either will do but for a pure white light I would go lower and for looks I would go higher.

 

[Cole]

This is a bit of a cross-post so forgive me for duplicating.

There is always a lively discussion about light temperature but the reality is this:
- Midday sunlight is typically between 5400 and 5800K depending on your latitude.
- TV and film lighting are typically HMI lights. HMI lights are a form of HID lighting that operate at specifically 5600K - as that represents white light.
- camera flash operates at 5500 - 5600K... again as that is "white" light.
- The lowest standard lighting temp used in photography is 5000K

Basically it all means white light is that which is between 5000 and 6000K. If you want your HID lights to be "white", you have a choice: 5000K or 6000K.

The human eye is more sensitive to yellow light (lower temperature) so the lower colour temperature 5000K offers a touch more contrast than 6000K. Thus for most people, erring on the lower side of the 5600K white benchmark is probably the better option.

Anything below 5000K or above 6000K is not proper white light.

On the lumen side of things ... lumens are measure of the light as seen by a human eye ... not a measure of light emitted. All 35w HIDs will emit the same amount of light, but those around 4100-4300K emit the most in the spectrum where the human eye is more sensitive, therefore lights in that range have a slightly higher lumen output. The HID light below 5000K has a slight yellow tinge and produces slightly more visible light.

3200 lumens is the visible output of a 35w HID around 4100-4300 K area. This falls slightly to 3000 lumens at 6000K and 2800 lumens at 8000K.

Realistically in my experience with HIDs there is no visible difference in light output at 4300K, 5000K or 6000K. But there is a visible colour difference. Overall I think 5000K is the probably best tradeoff for most people, but I prefer running 6000K - it has a kind of purity about it.

 

[Cole]

Just another thing to consider re light temperature ...

If you replace the W5W parking light bulb with a white LED bulb on the front of the bike you will need to consider that if the colour of the LED clashes with the colour of the HIDs, it will affect the "perception" of the colour of both. As mentioned in another post, the "colour" of the HID lights to the human eye is very much a relative thing, not an absolute thing.

White LEDs typically operate at 6500K. If you have a 5000K HID next to a 6500K LED, then the 5000K HID will look more yellow than it would otherwise. If you have white LEDs, then 6000K HIDs should be taken more seriously as it is pretty much a match for the LEDs.

A filament W5W bulb, even halogen ones totally coated in blue tint, look a sickly yellow next to a 5000K or 6000K HID burner.