experchange > linux.hardware

Bobbie Sellers (11-02-16, 03:52 AM)
Hi guys and gals,

Sad news but remediable. Should be spread around...

<https://www.scientificamerican.com/article/blue-leds-light-up-your-brain/?WT.mc_id=SA_HLTH_20161101>

DEA is going to be after this deleterious stimulant. ;^)

bliss
Doug Laidlaw (11-02-16, 11:44 AM)
On 02/11/16 12:52, Bobbie Sellers wrote:
> Hi guys and gals,
> Sad news but remediable. Should be spread around...
> <https://www.scientificamerican.com/article/blue-leds-light-up-your-brain/?WT.mc_id=SA_HLTH_20161101>
> DEA is going to be after this deleterious stimulant. ;^)
> bliss

It isn't just screens. "White" incandescent globes emit light with a
yellow tinge. "Whuite" LEDs in torches (flashlights) and in the modern
automobile lighting are at the blue end.

Doug.
TJ (11-02-16, 02:38 PM)
On 11/01/2016 09:52 PM, Bobbie Sellers wrote:
> Hi guys and gals,
> Sad news but remediable. Should be spread around...
> <https://www.scientificamerican.com/article/blue-leds-light-up-your-brain/?WT.mc_id=SA_HLTH_20161101>
> DEA is going to be after this deleterious stimulant. ;^)
> bliss

Oh, great. Now I'll have even MORE trouble staying awake through a prime
time TV program.

These people who have so much trouble falling asleep at night should try
doing a little physical labor once in a while. Believe me, after a day
of that, a couple of blue lights aren't going to stop you from sleeping.

TJ
Bobbie Sellers (11-02-16, 03:23 PM)
On 11/02/2016 02:44 AM, Doug Laidlaw wrote:
> On 02/11/16 12:52, Bobbie Sellers wrote:
> It isn't just screens. "White" incandescent globes emit light with a
> yellow tinge. "Whuite" LEDs in torches (flashlights) and in the modern
> automobile lighting are at the blue end.
> Doug.


Some people are required by the needs of study or occupation these days
to spend a lot of time looking at screens. This is basically
a problem for the indulgent parent who must deal with the effects of
late evening exposure to the tablet screens. Most workers in the IT
field have pretty much enough exposure at work.
No one is going to be staring at the new LED headlights.
The yellow tinge of incandescent bulbs does not have the
same effect as the blue-white of the LED.
You do not seem to have read the article. On my notebook I have
messed with the settings in display hardware to alter the gamma and
today have a faintly pink screen.
The f.lux software varies the screen color from whiter to redder
throughout the day and can be set for night workers in the opposite
direction(white in the evening and redder after dawn). Some Linux
version have f.lux in the repositories.

bliss
Bobbie Sellers (11-02-16, 03:28 PM)
On 11/02/2016 05:38 AM, TJ wrote:
> On 11/01/2016 09:52 PM, Bobbie Sellers wrote:
> Oh, great. Now I'll have even MORE trouble staying awake through a prime
> time TV program.
> These people who have so much trouble falling asleep at night should try
> doing a little physical labor once in a while. Believe me, after a day
> of that, a couple of blue lights aren't going to stop you from sleeping.
> TJ


Well when possible that is fine. When I was younger I pursued
physical activity. After I was in my 46th year that became impossible
and now at 79+ I am barely able to ambulate and carry home a few lbs
of food which I must then find the energy to cook. I also have had
injuries or simple wearing out of joints to contend with.

bliss
The Real Bev (11-02-16, 07:16 PM)
On 11/02/2016 02:44 AM, Doug Laidlaw wrote:
> On 02/11/16 12:52, Bobbie Sellers wrote:
> It isn't just screens. "White" incandescent globes emit light with a
> yellow tinge. "Whuite" LEDs in torches (flashlights) and in the modern
> automobile lighting are at the blue end.


I had wondered about people selling yellowish "gaming glasses". Is this
possibly what they're for?
Moe Trin (11-03-16, 02:18 AM)
On Wed, 2 Nov 2016 in the Usenet newsgroup alt.os.linux.mageia, in article
<c5poed-2oq.ln1>, Doug Laidlaw wrote:

>Bobbie Sellers wrote:


>> Sad news but remediable. Should be spread around...


Actually, several of the flat-panel monitors on the desktops here have
a setup menu that includes a 'color' feature - this HP2009M lets me
set the illumination to 9300K, 6500K, "sRBG" and a "custom" setting.
The Acer is somewhat similar, as is the LG.

>It isn't just screens. "White" incandescent globes emit light with a
>yellow tinge.


That's the nature of the beast - if you look at the wonky-pedia page
(), MOST incandescent
lamps are somewhere in the range of 2400-2600K.

>"Whuite" LEDs


I presume that to be a typ0

>in torches (flashlights)


because they tend to be under-powered - the "standard" torch (two NEDA
type 13AX - a.k.a. "D" cells and a PR-2 lamp) is nominal 1.5 watts, and
0.8 mean spherical candle power - which ain't a whole lot of lumens (if
I recall correctly, a "good" flashlight might have a peak 100 lumens in
the center of a vary narrow beam). The LED replacement may be similar
in light levels, but is 0.063 watts because the coin-cell batteries
aren't especially powerful. Again, looking at the wonky-pedia page
above, the light from a 5000-6500K source APPEARS brighter - meaning
you can see better with the same number of lumens.

>and in the modern automobile lighting are at the blue end.


Again, more APPARENT light for the bux. We just replaced the lamp
over the kitchen sink - we had a 3x40W track light, and it's now a
General Electric "under counter" fluorescent replacement (model 33847,
24 inch/61 cm 823 lumen LED lamp using 9 watts on "high" setting (800
lumens is about a 60 watt incandescent). The fascinating feature of
this particular lamp is the three position (electrical) switch is NOT
the "off/low/high" power switch (this one uses a motion sensor - wave
your hand under one side of the lamp, and it sets off/low/high), but
rather sets the color temperature (choice of Warm-White, Cool White and
Daylight). Playing with that switch DOESN'T change the amount of power
used, so I'm guessing it's two or three sets of LEDs hidden behind the
diffuser. Certainly was not cheap (US$50). With the energy saved, it
will pay for itself in ten or twenty years ;-) Oh, and using my
50 year old Weston Master IV (photographic) light meter, the "low"
light setting is about a quarter of the "high" (guessing 200 lumens(
and the power used doesn't even show on my "Kill-a-Watt" power meter
(less than 2 watts), but the light level is more than adequate for
casual lighting (i.e. not doing the dishes, or similar).

Incandescent lamps are getting harder to find here - if you go to the
lamp section of the hardware or home-improvement store, it's just
wall-to-wall compact-fluorescent-lamps and the more expensive LED lamps
(choice of Warm-White, Cool White and Daylight lamps in 15 to 150 watt
equivalent sizes) and maybe a dozen (total) incandescents (appliance
and reading lamps mainly). Problem is that incandescents will operate
over -50 to +60 C (-60 to +140F) or more, while the CFL and LED types
have electronics in them, and should be restricted to 0 to +40C max
(32 to 104F) which can be a problem outside here. But then, even the
regular (full sized) fluorescent tubes have temperature limits,
especially on the low side.

Old guy
Moe Trin (11-03-16, 02:19 AM)
On Wed, 2 Nov 2016, in the Usenet newsgroup alt.os.linux.mageia, in article
<nvd700$llh$2>, The Real Bev wrote:

>Doug Laidlaw wrote:


>> Bobbie Sellers wrote:


>>> Sad news but remediable. Should be spread around...


>> It isn't just screens. "White" incandescent globes emit light with
>> a yellow tinge. "Whuite" LEDs in torches (flashlights) and in the
>> modern automobile lighting are at the blue end.


>I had wondered about people selling yellowish "gaming glasses". Is
>this possibly what they're for?


Nah - that's to protect your eyes from those alien ray-guns that the
bad guys are using ;-)

Actually, for many years, competitive target shooters (using real guns
on outdoor ranges) MAY wear yellow tinted glasses (safety glasses if
you're smart), but that is to increase the contrast of the black rings
on the white paper target. (You may notice that traffic warning signs
are black on yellow rather than black on white, so that they can be
seen better - same rational.) I think I got my first pair of yellow
shooting glasses in 1955 or so. You need to be wearing a hat with a
large bill (or equal) to keep the sun out of the way though. Yellow
tinted glasses and bright sunlight don't work well together.

Old guy
Moe Trin (11-03-16, 02:21 AM)
On Wed, 2 Nov 2016, in the Usenet newsgroup alt.os.linux.mageia, in article
<nvcmmj$pv8$1>, TJ wrote:

>Bobbie Sellers wrote:


>> Sad news but remediable. Should be spread around...


>Oh, great. Now I'll have even MORE trouble staying awake through a
>prime time TV program.


There's something decent to watch on TV??? Wow!

>These people who have so much trouble falling asleep at night should
>try doing a little physical labor once in a while. Believe me, after a
>day of that, a couple of blue lights aren't going to stop you from
>sleeping.


There was an article about this recently - think it was probably in the
AARP magazine. My wife bought a clock-radio some time ago, with the
large (~3 inch) 7-bar display (she can't see well without the glasses).
The display was a greenish-blue, rather than the more common orange or
red. It lasted about two weeks before it was sent to Good-Will. The
replacement is the same size, but red, with the intensity set to low.

Old guy
Charlie Gibbs (11-03-16, 05:39 AM)
On 2016-11-02, Bobbie Sellers <bliss> wrote:

> Hi guys and gals,
> Sad news but remediable. Should be spread around...
><https://www.scientificamerican.com/article/blue-leds-light-up-your-brain/?WT.mc_id=SA_HLTH_20161101>
> DEA is going to be after this deleterious stimulant. ;^)


Hah! They can have it. Now I have scientific justification for my
hatred of the blue-LED craze. (Aside from my eyes' inability to
focus on those wavelengths.)
Charlie Gibbs (11-03-16, 05:44 AM)
On 2016-11-03, Moe Trin <ibuprofin> wrote:

> On Wed, 2 Nov 2016 in the Usenet newsgroup alt.os.linux.mageia, in article
> <c5poed-2oq.ln1>, Doug Laidlaw wrote:
> Actually, several of the flat-panel monitors on the desktops here have
> a setup menu that includes a 'color' feature - this HP2009M lets me
> set the illumination to 9300K, 6500K, "sRBG" and a "custom" setting.
> The Acer is somewhat similar, as is the LG.
> That's the nature of the beast - if you look at the wonky-pedia page
> (), MOST incandescent
> lamps are somewhere in the range of 2400-2600K.


I've been phasing in LED replacements for the 50-watt PAR20 halogens
in our pot lights. (They consume about 7 watts for the same amount
of light, and don't get hellishly hot like the halogens.) The 2700K
models (warm white) work pretty well. At least until you dim them.
The newer ones will dim decently without flickering, but they don't
get redder like the halogens do. This is a bit disconcerting,
especially if you have one of each on the same circuit.
Bobbie Sellers (11-03-16, 06:40 AM)
On 11/02/2016 08:39 PM, Charlie Gibbs wrote:
> On 2016-11-02, Bobbie Sellers <bliss> wrote:
> Hah! They can have it. Now I have scientific justification for my
> hatred of the blue-LED craze. (Aside from my eyes' inability to
> focus on those wavelengths.)


Try adjusting the gamma in System Setting/Hardware/Monitor toward red
and away from blue and green.
Might help.
bliss
Mike Spencer (11-03-16, 08:41 AM)
Moe Trin <ibuprofin> writes:

> Actually, for many years, competitive target shooters (using real guns
> on outdoor ranges) MAY wear yellow tinted glasses (safety glasses if
> you're smart), but that is to increase the contrast of the black rings
> on the white paper target.


Hey, there, Old Guy. You're the guy who bailed me out of a couple of
dialup problems awhile ago. Good to hear from you again.

The yellow shades also help shooting (or doing anything, for that
matter) on sun + snow where the blue is strong. IIRC, there's a
physiological explanation for why filtering the blue out sharpens
focus.

I have a pair here somewhere. I'll have to see what my laptop looks
like with them on.
Mike Spencer (11-03-16, 08:45 AM)
Charlie Gibbs <cgibbs> writes:

> Hah! They can have it. Now I have scientific justification for my
> hatred of the blue-LED craze. (Aside from my eyes' inability to
> focus on those wavelengths.)


I think the focus thing is true for everybody. You're just clueful
enough to have noticed. ;-)
The Real Bev (11-03-16, 08:46 AM)
On 11/02/2016 05:19 PM, Moe Trin wrote:
[..]
> shooting glasses in 1955 or so. You need to be wearing a hat with a
> large bill (or equal) to keep the sun out of the way though. Yellow
> tinted glasses and bright sunlight don't work well together.


My ski goggles are light yellow, and after a while the snow looks white
again through them. Even though I only ski in bright sunlight, I've
never noticed excessive brightness until I take the goggles off.

I just buy them at yard sales for a buck -- the previous owner got to
choose he color.

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