question about dashboard lighting

hsk1610 · 06-13-2014, 07:42 AM

Hi, recently noticed that at night, the gauges are red but at dusk or dawn, the odometer and the trip computer part of the dash will change back to white while the tach and the speedo stay red. Any idea why it does this? I have the extended cluster on my car.

Ali Shiralian · 06-13-2014, 07:48 AM

Quote:

Originally Posted by hsk1610

Hi, recently noticed that at night, the gauges are red but at dusk or dawn, the odometer and the trip computer part of the dash will change back to white while the tach and the speedo stay red. Any idea why it does this? I have the extended cluster on my car.

White is better to see during the day, it changes when it gets dark again for better visibility

Tonitron335i · 06-13-2014, 09:33 AM

Quote:

Originally Posted by Ali Shiralian

White is better to see during the day, it changes when it gets dark again for better visibility

+1

stormlv · 06-13-2014, 09:36 AM

To add to Ali's reply, why red (or orange) is a lot better to have at night.

As you know there are two types of photo receptors in our eyes. Rods and cones...
Cones are used for daytime color vision and rods are used for night black-white vision.
We have 3 types of cones (for red, green and blue hence color vision) but only one type of rod (hence black and white vision)

Rods are a lot more sensitive than cones, but because of that they quickly "bleach" in strong light and become useless during daylight. This is why you have to wait a while in a dark room so that the rods can regenerate the pigment sensitive to light.

Anyway, if you want to illuminate something at night, but not mess up your night vision, you have to illuminate it using a wavelength of light that the rods are not sensitive to.

Look at this image

Rods are most sensitive to blue-green and little to red.
If you use red light to illuminate something at night, the red sensitive cones will see it, but not the rods and keep your night vision intact.

This is the same reason why BMW uses orange for dials. It prevents you to "de-sensitise" your night vision....

JimmersBimmer · 06-13-2014, 10:32 AM

Stormlv,

Awesome reply!

visor · 06-13-2014, 10:45 AM

Stormlv has an excellent answer.

But back to the question, it's because you have the headlights set to auto. When they turn on automatically (when it's dark enough) or if you turn the switch to on, the orange LEDs are lit. Otherwise the white LEDs are on, eg during the day.

I know, I thought I was going crazy or seeing things during the first week.

f30GTR · 06-13-2014, 11:02 AM

Can any of this been coded to make it stay white the whole time? Just wondering.

hsk1610 · 06-13-2014, 11:53 AM

Thanks for all the great responses.

tturedraider · 06-13-2014, 12:56 PM

Quote:

Originally Posted by stormlv

To add to Ali's reply, why red (or orange) is a lot better to have at night.

As you know there are two types of photo receptors in our eyes. Rods and cones...
Cones are used for daytime color vision and rods are used for night black-white vision.
We have 3 types of cones (for red, green and blue hence color vision) but only one type of rod (hence black and white vision)

Rods are a lot more sensitive than cones, but because of that they quickly "bleach" in strong light and become useless during daylight. This is why you have to wait a while in a dark room so that the rods can regenerate the pigment sensitive to light.

Anyway, if you want to illuminate something at night, but not mess up your night vision, you have to illuminate it using a wavelength of light that the rods are not sensitive to.

Look at this image

Rods are most sensitive to blue-green and little to red.
If you use red light to illuminate something at night, the red sensitive cones will see it, but not the rods and keep your night vision intact.

This is the same reason why BMW uses orange for dials. It prevents you to "de-sensitise" your night vision....

Great answer. Just a little information diddy - in the Army your flashlight comes with a red filter for nighttime map reading and other uses. They teach you to immediately close one eye if you suddenly experience bright light at night in order to preserve your night vision in that eye.

rjpeaks · 06-13-2014, 01:22 PM

wow - that is informative Storm

EvenKeel · 06-13-2014, 02:33 PM

Quote:

Originally Posted by hsk1610

Hi, recently noticed that at night, the gauges are red but at dusk or dawn, the odometer and the trip computer part of the dash will change back to white while the tach and the speedo stay red. Any idea why it does this? I have the extended cluster on my car.

There is an ambient light sensor built into the instrument cluster.

This sensor operates independent of the auto headlight sensor.

This is why there can be a scenario when your headlamps automatically turn on, but, the instrument cluster remains white.

Want to observe the instrument cluster sensor in action? At nighttime take a flashlight and point it at the center of the cluster. A few seconds later, it will switch to white illumination as the sensor will perceive the flashlight as daylight.

visor · 06-13-2014, 02:38 PM

^ Kewl! Never knew that.

fecurtis · 06-13-2014, 03:43 PM

To my complete shock, my sales associate when I first test drove the car explained this to me, not quite to the depth that you guys did but he used the nature of the dashboard lighting working independently from whether or not the headlamps are on to explain the meticulous nature of how BMW thinks of things.

06-13-2014, 07:42 AM	#1
hsk1610 Lieutenant 108 Rep 524 Posts Drives: 2013 328i xDrive Join Date: Sep 2013 Location: Chicago, IL iTrader: (0)	question about dashboard lighting Hi, recently noticed that at night, the gauges are red but at dusk or dawn, the odometer and the trip computer part of the dash will change back to white while the tach and the speedo stay red. Any idea why it does this? I have the extended cluster on my car.
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06-13-2014, 09:36 AM	#4
stormlv Human 932 Rep 1,200 Posts Drives: Yes Join Date: Nov 2013 Location: Geneva iTrader: (1)	To add to Ali's reply, why red (or orange) is a lot better to have at night. As you know there are two types of photo receptors in our eyes. Rods and cones... Cones are used for daytime color vision and rods are used for night black-white vision. We have 3 types of cones (for red, green and blue hence color vision) but only one type of rod (hence black and white vision) Rods are a lot more sensitive than cones, but because of that they quickly "bleach" in strong light and become useless during daylight. This is why you have to wait a while in a dark room so that the rods can regenerate the pigment sensitive to light. Anyway, if you want to illuminate something at night, but not mess up your night vision, you have to illuminate it using a wavelength of light that the rods are not sensitive to. Look at this image Rods are most sensitive to blue-green and little to red. If you use red light to illuminate something at night, the red sensitive cones will see it, but not the rods and keep your night vision intact. This is the same reason why BMW uses orange for dials. It prevents you to "de-sensitise" your night vision.... __________________ 2023 BMW M4 CP xDr \| 510HP / 650Nm \| Isle of Man Green \| Photo album Sold 2018 BMW M4 DCT / ZCP\| 450HP / 550Nm \| Sakhir Orange \| Photo album \| Tribute Sold 2014 BMW 435xd \| 360HP / 710Nm \| Estoril Blue \| Photo album 2010 BMW Z4 sDrive35i DKG \| 306 HP / 400Nm \| Space Gray \| Photo album
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06-13-2014, 10:32 AM	#5
JimmersBimmer Private First Class 3 Rep 125 Posts Drives: 2017 M240i X-Drive Join Date: Mar 2014 Location: East of GTA, Ontario, Canada iTrader: (0)	Stormlv, Awesome reply! __________________ 2017 F22 White M240i on Black Leather 2016 F30 Silver 328 on Black Leather 2015 F30 Jet Black 328 on Coral Leather 2007 E90 Silver on Black Leather
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06-13-2014, 10:45 AM	#6
visor BMW, can I have some LSD please? 88 Rep 1,591 Posts Drives: 2017 F30 340i xDrive Join Date: Jun 2005 Location: Vancouver, Canada iTrader: (0)	Stormlv has an excellent answer. But back to the question, it's because you have the headlights set to auto. When they turn on automatically (when it's dark enough) or if you turn the switch to on, the orange LEDs are lit. Otherwise the white LEDs are on, eg during the day. I know, I thought I was going crazy or seeing things during the first week.
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06-13-2014, 11:02 AM	#7
f30GTR First Lieutenant 51 Rep 341 Posts Drives: 2014 AW F30 335i M-Sport MT Join Date: Oct 2008 Location: Chicago iTrader: (1)	Can any of this been coded to make it stay white the whole time? Just wondering.
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06-13-2014, 11:53 AM	#8
hsk1610 Lieutenant 108 Rep 524 Posts Drives: 2013 328i xDrive Join Date: Sep 2013 Location: Chicago, IL iTrader: (0)	Thanks for all the great responses.
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06-13-2014, 01:22 PM	#10
rjpeaks Lieutenant 14 Rep 577 Posts Drives: F30 335i M-Sport 6pd Join Date: May 2014 Location: Huntington Beach iTrader: (0)	wow - that is informative Storm __________________ 335I M-Sport 6spd EBII MPPK MPE DHP HK PDC ZTP ZPS ZPP ZDA ZPK 802.11ac ABC123
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06-13-2014, 02:38 PM	#12
visor BMW, can I have some LSD please? 88 Rep 1,591 Posts Drives: 2017 F30 340i xDrive Join Date: Jun 2005 Location: Vancouver, Canada iTrader: (0)	^ Kewl! Never knew that.
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06-13-2014, 03:43 PM	#13
fecurtis Banned 3262 Rep 6,299 Posts Drives: 2014 BMW 335i M-Sport Join Date: Jan 2014 Location: Arlington, VA iTrader: (0)	To my complete shock, my sales associate when I first test drove the car explained this to me, not quite to the depth that you guys did but he used the nature of the dashboard lighting working independently from whether or not the headlamps are on to explain the meticulous nature of how BMW thinks of things.
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