What LED digits color You like? <poll inside>

[james_s]

Why are daytime running lights a bad idea? They certainly increase visibility of oncoming cars to me.

[thm_w]

Why are daytime running lights a bad idea? They certainly increase visibility of oncoming cars to me.

Daytime running lights are clearly a good idea, unless you have some problem with reducing crashes by 5 to 30%.

Daytime running lights also protect the most vulnerable road users. Studies have found that they reduce certain motorcycle crashes by 23 percent and pedestrian accidents by 12 percent.
However, only 27 percent of the passenger vehicles currently on sale in the United States are fitted with daytime running lights as standard equipment.

https://www.ibiblio.org/rdu/DRLs/studies.htm
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2850978/
https://www.carnellfirm.com/blog/2017/09/daytime-running-lights-save-lives-and-reduce-accidents.shtml

[bitseeker]

But on the other hand why are we debating - use these in the device and pick your own color. 

https://www.adafruit.com/product/1399

Sure, as long everyone doesn't start putting them in everything with each segment a different color like that.

[xrunner]

Sure, as long everyone doesn't start putting them in everything with each segment a different color like that.

It might go good like that with that new Rigol DG800. No - I guess it doesn't need more bling. 

[TheUnnamedNewbie]

Isn't there a thing with red light not changing your eyes 'exposure' level? Which is why it is also (used to be?) used for torches for people doing searches at night, it doesn't break your night vision. I guess that might be a reason to go for red?

[bitseeker]

Yes, it's that low levels of red light (as opposed to other colors or white) reduce your retina's sensitivity less after it has already adapted to very low ambient light levels.

However, unless your lab is always really dark (that'd make for challenging work on small components), I don't think red LEDs vs. other colors will really matter. For astronomy or late-night stakeouts, it makes more sense.

[David Hess]

I also prefer the 'dot' style LEDs that HP used to use to more conventional seven segment units:

I like the dot style LED displays Tektronix used on their early instruments shown below.

[rdl]

I don't like yellow much, so I don't like the older green color LEDS because of the yellowish cast. I usually refer to them as snot green. You can get green LEDs with shorter wavelength that have a more blue look which I do like, but few companies seem to use them. Blue LEDs are fine as long as they are not too bright. My cable modem has LEDs that are green, blue and orange. The blue ones are the dimmest of the bunch and don't bother me at all.

[Fungus]

Isn't there a thing with red light not changing your eyes 'exposure' level? Which is why it is also (used to be?) used for torches for people doing searches at night, it doesn't break your night vision. I guess that might be a reason to go for red?

That's true for any primary color. Green and blue work just as well.

It's all down to brightness, IMHO. Add a brightness control and any color will do.

[Kleinstein]

Blue LEDs tend to be chosen rather bright. Some people have problems with blue, as it is scattered more and also chromatic aberrations of the eye can confuse focusing a little (not so bad with LEDs, but with blue / black contrast on the computer screen).  I usually prefer red, as the colored cover is usually best and helps with contrast.

[GeorgeOfTheJungle]

 

[bson]

Why are daytime running lights a bad idea? They certainly increase visibility of oncoming cars to me.

It also makes it obvious if a parked car has its engine running - if not, it's not a candidate to suddenly pull out in front of you.  Even if the driver turns the wheels.  Or, if the lights just went off it's because the engine was turned off, so expect a door to fly open and someone to step out into the street.  Basically, you can drive past entire blocks of parked cars, and any potential hazards advertise themselves with their headlights.

[TheBay]

Red or Amber for me, why is there no Amber option on this poll?
One thing I've always liked about the BMW's I've owned, they have always had Amber illumination.

Blue LED's are awful, they only belong in a RGB array.

[001]

why is there no Amber option on this poll?

See my previous post:

I write 'yelow' in the pool since it is the basicaly same orange/amber LEDs but in high bright mode
Looks attractive but why industrial meters didn`t use them? Is it for some ergonomix problems?

Theme became hot 

[TheBay]

why is there no Amber option on this poll?

See my previous post:

I write 'yelow' in the pool since it is the basicaly same orange/amber LEDs but in high bright mode
Looks attractive but why industrial meters didn`t use them? Is it for some ergonomix problems?

Theme became hot 

But you can get Orange, Yellow and Amber LED's, not being pedantic but they are all different.

[Cerebus]

Isn't there a thing with red light not changing your eyes 'exposure' level? Which is why it is also (used to be?) used for torches for people doing searches at night, it doesn't break your night vision. I guess that might be a reason to go for red?

That's true for any primary color. Green and blue work just as well.

It's all down to brightness, IMHO. Add a brightness control and any color will do.

Er no, blue and green don't work as well. It's down to the fact that you have two vision systems rods (scotopic) and cones (photopic). The scotopic system works in low light conditions (think moonlit mcd/m² or starlit µcd/m²) and only gives you monochrome vision, the photopic system works in brighter light and gives you colour vision. If you look at the spectral sensitivity curves for the two systems you'll see that scotopic vision (V'(λ) in the graph) is almost completely insensitive to red.



The pigments in the visual system that respond to light suffer from bleaching, depletion in bright conditions where it takes time for the pigment to be regenerated. You can see this for yourself by looking at a bright object, close your eyes and you'll see an image persist on your retina for as much as several seconds. In daylight conditions the scotopic pigments are in a semi-permanent 'bleached out' condition which is why it takes time for your vision system to adapt to low light.

The scotopic system fails to absorb at long wavelengths so does not suffer the bleaching effect if it is only exposed to red light and thus red doesn't ruin your dark adaption. Expose yourself to bright monochromatic green or blue light and you will destroy your scotopic dark adaption. Following the response curve for the scotopic pigments, the shorter the wavelength (up to around a 480 nm peak) the more effect it will have on your night adapted vision.

If you're in low light, but bright enough to still be photopic conditions then monochromatic blue, green or red light would all be partially protective of low light colour vision as long as they were used singly as there are three photo-pigments involved in the photopic regime.

In daylight conditions the scotopic pigments will still respond to really bright stimuli, which is why some bright blue lights (LEDs) near the sensitivity peak for scotopic vision are irritating as they are partially activating your night vision system while you're actively using your daylight vision system.

[Nisei]

Back in the days when nearly the only color being used was red (particularly alarm clocks) it was cool to see other colors become available.
However, I've been using other colors now and then but I still prefer red nowadays.
I always use 2 layers of Lee 027 medium red filter in front of the display. It looks nearly black when turned off and it perfectly lets the red wavelength pass so it gives great contrast without reducing brightness.

[TheBay]

Red was always best for the bedroom as you can't see it when your eyes are closed, I stayed in a hotel with a Blue LED alarm clock. No idea who thought that was a good idea!

Back in the days when nearly the only color being used was red (particularly alarm clocks) it was cool to see other colors become available.
However, I've been using other colors now and then but I still prefer red nowadays.
I always use 2 layers of Lee 027 medium red filter in front of the display. It looks nearly black when turned off and it perfectly lets the red wavelength pass so it gives great contrast without reducing brightness.

Also colour differences, I took a picture of this earlier on my car.
Orange led compared to Amber led, the colour balance of my camera has skewed it somewhat but in real life the petrol symbol is Orange and the mileage etc is deep Amber.

[001]

September tread is not necroposting isnt it? 
It was very interesting to know yours favorite indicator color 
AND WHAT ABOUT HEIGHT?

[Gyro]

The killing Flukes thread AND this?

[001]

The killing Flukes thread AND this?

what do You mean? 

[Gyro]

I mean it's an utterly pointless question - High enough to be comfortably readable at whatever distance you're reading it - Obviously!

You wan't to know about blowing up Flukes without being bothered to watch the video you were pointed to, now this - it's rather too much from one person in the space of an hour!

[001]

I mean it's an utterly pointless question - High enough to be comfortably readable at whatever distance you're reading it - Obviously!

One my friend put 2" ticker on the bench   
It is not cool for my eyes

[cdev]

A couple of years ago I went looking for info on why my eyes hurt badly when forced to look at ultrabright blue LEDs, and I found a lot of stuff.

https://www.ncbi.nlm.nih.gov/pubmed/?term=%22blue+led%22  (only the deepest blue LEDs have this problem, whitish blues like the ones in VFDs dont!)

Mixed in there I also found some interesting info on other colors. Green LEDs have no problems at all, it seems and green is also the most visible color so you can use dimmer LEDs and maintain sharpness and legibility. I dont like super bright green that much, I always turn it down, but even super bright green does not hurt my eyes like blue does. Also green LEDs seem to last the longest of the non-red colors.

I also like red. Orange is okay too.

[stj]

maybe the chinese will make 7segment displays with near-UV leds.
then we can put "interesting" phosphor doped filters in front of them.