What LED digits color You like? <poll inside> - Page 1
Forum section: electronics / testgear

author: 001
author_rank: Super Contributor
timestamp: September 12, 2018, 09:34:04 am
content: What LED digits color You like?For Power Supply, counters, volmeters?

author: Muttley Snickers
author_rank: Unknown
timestamp: September 12, 2018, 10:14:26 am
content: I cannot find it now but somebody recently posted an image of a bench meter which had an orange seven segment display, it was the best I have ever seen so I need to go find that picture again.I voted for orange.

author: capt bullshot
author_rank: Super Contributor
timestamp: September 12, 2018, 10:26:27 am
content: Quote from: Muttley Snickers on September 12, 2018, 10:14:26 amThat might be one of the Datron 1061 or similar:

author: RoGeorge
author_rank: Super Contributor
timestamp: September 12, 2018, 10:36:17 am
content: NOT blue. Blue is the worst color for a display. I will also avoid white. The rest are OK.Your poll should allow to pick more than one color.

author: capt bullshot
author_rank: Super Contributor
timestamp: September 12, 2018, 10:56:16 am
content: That kind of white is acceptable:Otherwise, I second the opinion blue and white LED displays are not acceptable. Blue LED displays hurt my eyes.

author: GeorgeOfTheJungle
author_rank: Super Contributor
timestamp: September 12, 2018, 10:58:48 am
content: Yellow, orange, and red.

author: bloguetronica
author_rank: Frequent Contributor
timestamp: September 12, 2018, 11:00:23 am
content: Red is a classic. But I tend to favor orange and yellow (or orange yellow) too.Kind regards, Samuel Lourenço

author: Fungus
author_rank: Super Contributor
timestamp: September 12, 2018, 11:07:19 am
content: Quote from: capt bullshot on September 12, 2018, 10:56:16 amI think it depends almost 100% on the brightness.Retro red LEDs tend to be dim so they're relaxing.Anybody who puts modern blue LEDs on anything is usually the sort of person who makes them far too bright. Bright blue makes eyes hurt. Dim blue? That can be OK.Same goes for green. Dim green is quite nice, bright green isn't.Really bright red is probably horrible, too.Whatever you choose: Add a brightness control.

author: GreyWoolfe
author_rank: Unknown
timestamp: September 12, 2018, 01:37:46 pm
content: Almost everything is red except the GW Instek GDM-8251A meter, it's green. It's not a dim green nor a bright green but sort of in the middle. I like it but I prefer red. Interestingly about blue, Mrs GreyWoolfe's Hyundai Sonata has blue LEDs in the center console. Set at the right level, it is actually quite nice and I like it. At full brightness, not so much, it is painful as Fungus says.

author: emece67
author_rank: Frequent Contributor
timestamp: September 12, 2018, 02:53:57 pm
content: .

author: JPortici
author_rank: Super Contributor
timestamp: September 12, 2018, 03:05:42 pm
content: Orange = Best color ever.Lecroy, anybody?Also, my old car (fiat grande punto) had all the instrumentation lights orange. One of the few things i miss from that carBut since there was no option for orange i voted for whiteMy new car (skoda octavia) has all the instrumentation with the white LEDs, the monochrome display is white on black, too. Very pleasing to my eyes. Many times more pleasing that the red they use in the volkswagen assembly of the instrumentation clusterQuote from: GreyWoolfe on September 12, 2018, 01:37:46 pmone friend of mine has a honda but for the life of me i can't remember the model. The instrumentation cluster is a bit strange and many blue lights inside. The first time i went in i was somewhat puzzled (and kept looking around for cops.. damn blue lights) but after a bit i liked it. futuristic... in a good sense!

author: james_s
author_rank: Super Contributor
timestamp: September 12, 2018, 04:00:52 pm
content: Quote from: capt bullshot on September 12, 2018, 10:26:27 amThose aren't LED though, they're Sperry neon 7-segment displays. Unique and very attractive displays, but the lifespan is finite and replacements are virtually impossible to find.

author: bitseeker
author_rank: Super Contributor
timestamp: September 12, 2018, 05:19:06 pm
content: Quote from: james_s on September 12, 2018, 04:00:52 pmAlso goes by the trademark, Panaplex. Very cool displays but, like VFD, they don't last. I still like 'em, though.Quote from: Muttley Snickers on September 12, 2018, 10:14:26 amMight you be referring tothis HP 3457A conversion(click image to enlarge)?I really like the yellow LEDs for that meter.So, to answer the poll question, for me the color depends on the device it's going into.

author: Bud
author_rank: Super Contributor
timestamp: September 12, 2018, 05:59:52 pm
content: Orange is missing from the vote list. My choice is Orange.

author: Gyro
author_rank: Super Contributor
timestamp: September 12, 2018, 07:37:07 pm
content: Yep, Orange (the colours are a lot closer than they look in the photo). Orange LEDs look very nice too though.Quote from: james_s on September 12, 2018, 04:00:52 pmTheir finite lifespan is considerably longer than VFD though, although to be fair, they will probablyalreadyhave lived a very long time!

author: Sylvi
author_rank: Regular Contributor
timestamp: September 12, 2018, 08:13:29 pm
content: HiI do not understand the fashion for blue lights on everything?Blue is actually a very difficult colour for us to see and it often sort of vibrates. This is really bad when you have blue lights on the front of a grey or black vehicle since the light is almost like a cloaking device.AMBER is the best display colour as it has the same soft appeal as neon.

author: tautech
author_rank: Super Contributor
timestamp: September 12, 2018, 08:15:43 pm
content: Nipple pink of breast flesh white !I know, I'll grab my hat and coat.....bye.

author: DaJMasta
author_rank: Super Contributor
timestamp: September 12, 2018, 08:34:04 pm
content: I've always liked the sort of amber yellow, and for lower light situations, green is good too. You can't really go wrong unless your blues/whites are so bright they leave afterimages when you look away....

author: tkamiya
author_rank: Super Contributor
timestamp: September 12, 2018, 09:11:27 pm
content: I like every color EXCEPT for RED. When placed behind a red plastic, contrast is too low to see well. I have a B&K DVM like this. I think human eyes are less sensitive to reds as well. I understand, that's why, cockpit of small aircraft are often illuminated with red. Your eyes does not adjust to red much, so your night vision is unaffected to watch for traffic.

author: rf-loop
author_rank: Super Contributor
timestamp: September 12, 2018, 09:29:53 pm
content: Orange - amber.In some special cases, dark red (if necessary keep eyes very well adapted to deep darkness)If I see the blue LED. I know it works with smoke. When I take out the smoke it will no longer work.

author: mmagin
author_rank: Frequent Contributor
timestamp: September 12, 2018, 09:41:39 pm
content: I would generally prefer any of amber, yellow, green. Red isn't bad but the eye is a lot less sensitive at those wavelengths. With blue, I find it harder to focus on it in some lighting conditions, the eye is also less sensitive, and if it's bright enough it can mess with circadian rhythms if viewed at night.

author: 001
author_rank: Super Contributor
timestamp: September 13, 2018, 01:06:34 am
content: yeaI hate blue LEDs too! Who is evil inventor of blue LED indicators? But I see blue LEDs are popular in Asia - see car examples above and all crap audios from ebayWhat about amber and orange? I write 'yelow' in the pool since it is the basicaly same orange/amber LEDs but in high bright modeLooks attractive but why industrial meters didn`t use them? Is it for some ergonomix problems?

author: David Hess
author_rank: Super Contributor
timestamp: September 13, 2018, 02:28:22 am
content: Anything is generally acceptable except blue. Blue can die in a fire.

author: james_s
author_rank: Super Contributor
timestamp: September 13, 2018, 03:20:10 am
content: Quote from: Gyro on September 12, 2018, 07:37:07 pmIn either case it depends on how hard they're driven. I have a VFD based alarm clock that has been in service for over 30 years and the display still looks nice. It's not quite as bright as a new one but it's perfectly usable. The neon based displays can last a long time too if you under-drive them a bit. Panaplex is the name for the multi-segment displays that are internally wired for multiplexed drive.

author: David Hess
author_rank: Super Contributor
timestamp: September 13, 2018, 03:37:01 am
content: Quote from: james_s on September 13, 2018, 03:20:10 amControlling the drive by itself is not enough. VFDs and neon displays suffer from electrode sputtering which eventually makes the less used electrodes dim and fail. Test patterns can be used to minimize or reverse this.

author: james_s
author_rank: Super Contributor
timestamp: September 13, 2018, 03:47:14 am
content: Generally the poisoned cathodes will recover with use, sputtering normally refers to cathode material being vaporized and depositing on the glass or other internal structures. VFDs have multiple mechanisms responsible for the fading. One is phosphor aging which is directly related to how hard it is driven, the other is cathode emission dropping, which can often be recovered at least for a while by overdriving the filaments for a few seconds. It's true that both display techs have finite lifespans although LED displays don't last forever either.One thing I forgot to mention earlier is white LED displays. They look cool when new but they deteriorate faster than any other display type I can think of other than possibly OLED. Some of the products we made at a previous place I worked had white 7-segment displays for the clock on the front panel and within a year the more used segments/digits had become considerably dimmer and grayish looking. They looked like crap.

author: Gyro
author_rank: Super Contributor
timestamp: September 13, 2018, 07:43:04 am
content: I normally reduce the operating current of my panaplex display equipped gear when I get it - they are normally a bit too bright for a small domestic lab anyway. Luckily, the standard DS8881 drivers have a programming pin for this. Yes, I've successfully recovered poisoned incompletely lit segments on standard Sperry / Beckman displays with a bit more drive to clean the surface. Luckily the stuff I have uses standard pinout 1 1/2 to 3 digit displays. I know the custom Datron 106x/7x display can cause problems and because they're multiplexed, it can be difficult to revive them.I've only ever seen one Beckman display that was visibly sputtered (cathode material deposit on glass) but that still worked fine, with no apparent loss in brightness.It's sad to see a failing VFD, they can be filtered to a rather sickly yellow but you loose a lot of light output. One tip I got from a Noritake rep several years ago is to avoid phospors other than green. Red apparently poisons the display (not sure if it is cathode or phosphor poisoning), that's why you typically only see a single tiny red record icon etc. on VCR displays.

author: GeorgeOfTheJungle
author_rank: Super Contributor
timestamp: September 13, 2018, 08:26:26 am
content: The Victor desktop calculators of the 70's had those displays too.

author: Bud
author_rank: Super Contributor
timestamp: September 13, 2018, 02:23:23 pm
content: Quote from: Sylvi on September 12, 2018, 08:13:29 pmNot sure if that is the case. In Toronto the public transit buses have two blue lights placed just below the roof line at the front of the cabin. They are blue, not whity washed ones. When you are waiting for a bus and look up the street you can see lights from the approaching bus in traffic at quite a distance, even at day time, so you see that a bus is coming.

author: Fungus
author_rank: Super Contributor
timestamp: September 13, 2018, 02:39:20 pm
content: Quote from: Bud on September 13, 2018, 02:23:23 pmI have no problem seeing the sky, or anything else that's blue.(the sky is usually blue where I live, YMMV)

author: xrunner
author_rank: Super Contributor
timestamp: September 13, 2018, 02:41:18 pm
content: White is the best choice - that's why it's winning in the poll.

author: Fungus
author_rank: Super Contributor
timestamp: September 13, 2018, 03:00:25 pm
content: Quote from: xrunner on September 13, 2018, 02:41:18 pmIs that because there's no "orange" option?Maybe if we add red+yellow together it'll beat white.

author: GeorgeOfTheJungle
author_rank: Super Contributor
timestamp: September 13, 2018, 03:21:57 pm
content: Blue is ugly, and a sure sign of chinesium inside :-)

author: Fungus
author_rank: Super Contributor
timestamp: September 13, 2018, 07:11:45 pm
content: Quote from: GeorgeOfTheJungle on September 13, 2018, 03:21:57 pmYeah, no western designer ever specified blue LEDs for anything. Right?

author: tautech
author_rank: Super Contributor
timestamp: September 13, 2018, 07:30:39 pm
content: Quote from: xrunner on September 13, 2018, 02:41:18 pmI started that !Others have devious minds too.

author: floobydust
author_rank: Super Contributor
timestamp: September 13, 2018, 07:35:47 pm
content: I'm surprised LED display manufacturers are not offering anything different.First place is blue-green, it's a blue LED with VFD-coloured phosphor. Rarely seen, I think it's a custom part.Kingbrightoffers pastel colours for discrete LED's, we should talk them into making "ice blue" 7, 14-seg displays.Second place is white, with a tinted display window/bezel to get many colours.

author: lowimpedance
author_rank: Super Contributor
timestamp: September 14, 2018, 12:03:12 am
content: Quote from: Gyro on September 12, 2018, 07:37:07 pmAmber/orange just feels right for me, just looks the part. But I'm showing my age here as I have used gear with glowing orange 'tube' displays when it was still current tech.@ gyro ,I see an EW604 from Feedback Test Inst. on the top shelf there, I have one as well (with the old death style binding posts too, not the recessed sockets as on yours). And I also the manual if you don 't have a copy !.

author: Fungus
author_rank: Super Contributor
timestamp: September 14, 2018, 12:15:38 am
content: Quote from: lowimpedance on September 14, 2018, 12:03:12 amOK, as long as you add a motor to move the 7 segments backwards and forwards to match the displayed number.

author: lowimpedance
author_rank: Super Contributor
timestamp: September 14, 2018, 12:44:35 am
content: No need for motors ! , just move head to get correct perceived/wanted number.

author: pilotchup
author_rank: Unknown
timestamp: September 14, 2018, 02:32:53 am
content: I am thoroughly surprised Yellow (Orange) is doing poorly, looks the best by far IMO. Amazing how diverse the opinions are haha.

author: floobydust
author_rank: Super Contributor
timestamp: September 14, 2018, 02:36:45 am
content: Quote from: Fungus on September 14, 2018, 12:15:38 amI have a 7-segment display that is completely mechanical. It is from a 1970's alarm-clock radio. Backlit by #194 lamps and a mechanical shutter arrangement and a 1rpm motor.I kept it to someday disassemble and figure out.

author: james_s
author_rank: Super Contributor
timestamp: September 14, 2018, 03:27:29 am
content: Quote from: floobydust on September 14, 2018, 02:36:45 amI have a clock like that too, it's the only one like it I've ever seen though I did see a picture of the same mechanism in a clock radio somewhere online. I found it in a thrift store for $5 "needs repair", the bulbs were burned out of course. It seems these are exceedingly rare, it's one of my favorite clocks in my collection.

author: Brumby
author_rank: Unknown
timestamp: September 14, 2018, 03:54:37 am
content: My only problem with blue LEDs is not with the colour. It's the fact that they seem to be implemented at brightness levels that approach the intensity of landing lights for a light aircraft.SWMBO has a computer tower that has blue LEDs for power and disk activity - and, at night, they can cast a visible shadow of someone passing by on a wall 5m away.

author: james_s
author_rank: Super Contributor
timestamp: September 14, 2018, 04:05:03 am
content: Quote from: Bud on September 13, 2018, 02:23:23 pmBlue is easy to see, but difficult to focus on. It tends to look blurry and causes eye strain. I remember setting up the old CRT projection TVs and the blue always looked out of focus no matter how sharp it was. I see the same effect with bright blue LEDs.

author: Cubdriver
author_rank: Unknown
timestamp: September 14, 2018, 07:08:00 am
content: For seven segment LED stuff, I'm partial to the classics - red, green and yellow/amber.My favorites remain nixies, followed closely by Panaplex. Incidentally, the Panaplex stuff I have all has them filtered with red rather than amber.This image is a bit blown out exposure-wise, but shows the red filtered Panaplex:And this is a bare three digit Panaplex display:I also prefer the 'dot' style LEDs that HP used to use to more conventional seven segment units:I think it's wonderful that blue LEDs were developed, but would like to string up the designers/marketers who insist on using them at eye searing brightness on EVERYTHING! It's supposed to be an indicator, not a cutting laser!-Pat

author: Gyro
author_rank: Super Contributor
timestamp: September 14, 2018, 08:49:52 am
content: Quote from: lowimpedance on September 14, 2018, 12:03:12 amWell spotted. It's always fun to run a curious eye over other stuff lurking in the background of photos.Yes, I converted the deathtrap input terminals (1kV rated instrument) to shielded sockets myself. I needed to open out the holes with a step drill (or possiby taper reamer) but was able to do it carefully by hand without dismantling. I used the Hirschmann ones with threaded studs so the wiring loom can be simply transferred without modification, eg.https://uk.farnell.com/hirschmann-testmeasurement/972354101/banana-socket-32a-4mm-panel-red/dp/1011402?st=socket%204mm. Feedback did introduce the EW1604 to address the safety issue but bodged the fuseholder in a silly place on the front panel, much better keeping it at the back:https://fenix.tecnico.ulisboa.pt/downloadFile/3779571779276/LAB_IMd_Feedback_EW1604.pdfThanks for the offer, but there's already a scan on KO4BB...http://www.ko4bb.com/getsimple/index.php?id=download&file=06_Misc_Test_Equipment/Feedback_EW604_Electronic_Wattmeter_Service_Manual.pdf. I've also just noticed a nice clean original PDF one athttp://www.ee.bgu.ac.il/~intrlab/manuals/Feedback%20EW604.pdf.P.S. If yours has the O/P 1VFS socket to the right of the meter movement then it's best to disconnect that too as it becomes live at high voltage (it was deleted from later meters)!

author: lowimpedance
author_rank: Super Contributor
timestamp: September 14, 2018, 11:00:11 am
content: Thanks for the info.The later model 1604 did remove those dangerous posts and looks like you're meter.Will do the same mod to mine.

author: xrunner
author_rank: Super Contributor
timestamp: September 14, 2018, 02:08:50 pm
content: 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

author: Sylvi
author_rank: Regular Contributor
timestamp: September 14, 2018, 02:43:10 pm
content: Hey BudThe TO Blue-line buses were ones that ran all night.It is a mystery that blue lights are allowed on vehicles other than snow plows and cop cars? There seems to be zero regulation regarding vehicle lighting, now with the blue lights and silly white LEDs everywhere. Just because a municipality or big business decides to do something does not mean it is a good idea. Driving lights are a really bad idea. Daytime running lights are a bad idea. Blue LEDs are a bad idea.On equipment, blue flourescent displays were the rage in the eighties or so, but these were a softer blue - maybe more greenish - than modern blue LEDs. Then LCDs came out and you couldn't read anything.Another bad idea is the laser-etched text on nearly all consumer electronics and components. Burning the surface a little does not create a high-contrast print as you had with silk-screening. Sure lasers are faster and cheaper, but the panel text is invisible and part numbers are really difficult to read.One of the nicest car interiors was a jetta from about 2016 with its red LEDs. There are too many lights inside a car but these were unobtrusive at night despite not being able to dim them.

author: Gyro
author_rank: Super Contributor
timestamp: September 14, 2018, 04:17:35 pm
content: QuoteThat amazed me the first time I visited Korea. I saw trucks, large and small, displaying lights of pretty much every colour you could think of! You'll definitely get pulled if you display blue lights in the UK (emergency vehicles as you say) and I think, Green (Doctor).

author: james_s
author_rank: Super Contributor
timestamp: September 14, 2018, 04:35:17 pm
content: Why are daytime running lights a bad idea? They certainly increase visibility of oncoming cars to me.

author: thm_w
author_rank: Super Contributor
timestamp: September 14, 2018, 09:59:39 pm
content: Quote from: james_s on September 14, 2018, 04:35:17 pmDaytime running lights are clearly a good idea, unless you have some problem with reducing crashes by 5 to 30%.Quotehttps://www.ibiblio.org/rdu/DRLs/studies.htmhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC2850978/https://www.carnellfirm.com/blog/2017/09/daytime-running-lights-save-lives-and-reduce-accidents.shtml

author: bitseeker
author_rank: Super Contributor
timestamp: September 15, 2018, 01:27:43 am
content: Quote from: xrunner on September 14, 2018, 02:08:50 pmSure, as long everyone doesn't start putting them in everything with each segment a different color like that.

author: xrunner
author_rank: Super Contributor
timestamp: September 15, 2018, 01:45:39 am
content: Quote from: bitseeker on September 15, 2018, 01:27:43 amIt might go good like that with that new Rigol DG800. No - I guess it doesn't need more bling.

author: TheUnnamedNewbie
author_rank: Super Contributor
timestamp: September 15, 2018, 06:31:40 am
content: 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?

author: bitseeker
author_rank: Super Contributor
timestamp: September 15, 2018, 05:02:09 pm
content: 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.

author: David Hess
author_rank: Super Contributor
timestamp: September 16, 2018, 02:09:05 am
content: Quote from: Cubdriver on September 14, 2018, 07:08:00 amI like the dot style LED displays Tektronix used on their early instruments shown below.

author: rdl
author_rank: Super Contributor
timestamp: September 16, 2018, 10:33:09 am
content: 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.

author: Fungus
author_rank: Super Contributor
timestamp: September 16, 2018, 12:07:01 pm
content: Quote from: TheUnnamedNewbie on September 15, 2018, 06:31:40 amThat'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.

author: Kleinstein
author_rank: Super Contributor
timestamp: September 16, 2018, 05:00:27 pm
content: 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.

author: bson
author_rank: Unknown
timestamp: September 17, 2018, 07:11:21 am
content: Quote from: james_s on September 14, 2018, 04:35:17 pmIt 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.

author: TheBay
author_rank: Unknown
timestamp: September 17, 2018, 10:00:55 am
content: 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.

author: 001
author_rank: Super Contributor
timestamp: September 17, 2018, 01:24:28 pm
content: Quote from: TheBay on September 17, 2018, 10:00:55 amSee my previous post:Quote from: 001 on September 13, 2018, 01:06:34 amTheme became hot

author: TheBay
author_rank: Unknown
timestamp: September 17, 2018, 01:25:44 pm
content: Quote from: 001 on September 17, 2018, 01:24:28 pmBut you can get Orange, Yellow and Amber LED's, not being pedantic but they are all different.

author: Cerebus
author_rank: Super Contributor
timestamp: September 17, 2018, 02:26:35 pm
content: Quote from: Fungus on September 16, 2018, 12:07:01 pmEr 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/m2or 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 lightcolourvision 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.

author: Nisei
author_rank: Regular Contributor
timestamp: September 17, 2018, 04:09:09 pm
content: 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.

author: TheBay
author_rank: Unknown
timestamp: September 17, 2018, 04:42:11 pm
content: 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!Quote from: Nisei on September 17, 2018, 04:09:09 pmAlso 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.

author: 001
author_rank: Super Contributor
timestamp: November 28, 2018, 09:15:45 pm
content: September tread is not necroposting isnt it?It was very interesting to know yours favorite indicator colorAND WHAT ABOUT HEIGHT?

author: Gyro
author_rank: Super Contributor
timestamp: November 28, 2018, 10:09:17 pm
content: The killing Flukes thread AND this?

author: 001
author_rank: Super Contributor
timestamp: November 28, 2018, 10:14:17 pm
content: Quote from: Gyro on November 28, 2018, 10:09:17 pmwhat do You mean?

author: Gyro
author_rank: Super Contributor
timestamp: November 28, 2018, 10:17:58 pm
content: 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!

author: 001
author_rank: Super Contributor
timestamp: November 28, 2018, 10:22:06 pm
content: Quote from: Gyro on November 28, 2018, 10:17:58 pmOne my friend put 2" ticker on the benchIt is not cool for my eyes

author: cdev
author_rank: Super Contributor
timestamp: November 28, 2018, 10:40:07 pm
content: 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.

author: stj
author_rank: Super Contributor
timestamp: November 29, 2018, 02:43:00 am
content: maybe the chinese will make 7segment displays with near-UV leds.then we can put "interesting" phosphor doped filters in front of them.