Desk/Lab lighting tips?

[GreyWoolfe]

Are the bulbs standard T-5 or the HO bulbs?  Watch the heat output of those bulbs.  T-5 HO bulbs are popular in aquarium lighting but almost everything I have read about them is that they give off a lot of heat.  That is why I didn't go with T-5s in my office.  I didn't want to make the window air conditioner work any harder than it has to.  The office was an addition on the house by the previous owner and is not tied into the house AC.  The T-8 bulbs work almost as well with less heat output.

[enz]

I'm using a dual head graphics card.  What are you running?

ATI Radeon HD5700 with these monitors:
1. IIyama Prolite E2670WSD with 1920 x 1200
2. Benq FP91GX with 1280 x 1024

[Marco]

Wow, never knew some LED monitors used PWM at such ridiculously low frequencies ... that doesn't make any sort of sense, they already need a DC DC converter any way for the LEDs why then follow that up with some hacky PWM?

[eKretz]

Are the bulbs standard T-5 or the HO bulbs?  Watch the heat output of those bulbs.  T-5 HO bulbs are popular in aquarium lighting but almost everything I have read about them is that they give off a lot of heat.  That is why I didn't go with T-5s in my office.  I didn't want to make the window air conditioner work any harder than it has to.  The office was an addition on the house by the previous owner and is not tied into the house AC.  The T-8 bulbs work almost as well with less heat output.

Yes, this is very true. My main workbench lighting is a 4-bulb 48" T5HO fixture running the 54W bulbs @4100K. I love the light, it makes for an amazingly bright work area, but it definitely kicks out some heat. I have my work area in the basement so it isn't a problem for me - it actually helps warm it up a bit. Originally the fixture was installed over a 72 Gal. aquarium in my living room - that caused a litany of heating issues, the living room was certainly the warmest room in the house then, but the chiller on the aquarium ran a lot! There are also lower wattage T5 (non-HO?) bulbs available too, but then one might just as well run a T8 fixture really.

[mrflibble]

Wow, never knew some LED monitors used PWM at such ridiculously low frequencies ... that doesn't make any sort of sense, they already need a DC DC converter any way for the LEDs why then follow that up with some hacky PWM?

Main reason I can think is of color. If you PWM the led at a certain fixed current then the spectrum of the light emitted will be constant. If you lower the led current by going DC then you will get a color shift. So basically PWM-ing the leds makes color management easier.

[owiecc]

If you PWM the led at a certain fixed current then the spectrum of the light emitted will be constant. If you lower the led current by going DC then you will get a color shift. So basically PWM-ing the leds makes color management easier.

But this does not answer why they use _low_ PWM frequency.

[mrflibble]

If you PWM the led at a certain fixed current then the spectrum of the light emitted will be constant. If you lower the led current by going DC then you will get a color shift. So basically PWM-ing the leds makes color management easier.

But this does not answer why they use _low_ PWM frequency.

Beats me.  I was just responding to Marco's question on why they would use PWM at all.

... they already need a DC DC converter any way for the LEDs why then follow that up with some hacky PWM?

Incidentally, how low a frequency are we talking about here?

[c4757p]

If you PWM the led at a certain fixed current then the spectrum of the light emitted will be constant. If you lower the led current by going DC then you will get a color shift. So basically PWM-ing the leds makes color management easier.

But this does not answer why they use _low_ PWM frequency.

EMI?

[AndersAnd]

If you PWM the led at a certain fixed current then the spectrum of the light emitted will be constant. If you lower the led current by going DC then you will get a color shift. So basically PWM-ing the leds makes color management easier.

But this does not answer why they use _low_ PWM frequency.

The lower the switching frequency, the less switching losses.

[AndersAnd]

Wow thanks for that information

I am getting constant headaches and 24/7 vertigo which worsens by certain factors, I have had 4 MRI's, Lumbar punctures etc, they don't really know what's going on but some things trigger it like mad, such as LED monitors, Macbooks (tried a few and could not use them), they all seem to be okay at full brightness but it's as soon as I dim them I can see the flicker and get intense headaches, which is obviously due to the duty cycle of switching the LED's, this other technology looks interesting.

Some shop lighting drives me mad, I can't shop in Tesco due to their lighting, incandescent lighting is fine even if driven by PWM, but due to the nature of those lamps you would probably never see the flicker as they will glow between stages, where as an LED is instantaneous.

I have a Ducky mechanical keyboard, but cannot use the backlighting as the flickering is obvious, years ago I couldn't use a PC with the refresh rate on a CRT @50/60hz, would drive me nuts.

I have been looking at running some LED lighting, are yours directly driven or any form of PWM, I am susceptible to migraine and any flickering sets me off.
I am stuck with CCFL monitors.

Have you tried one of the newer flicker free LED backlit monitors?
Eizo and BenQ both make a range of flicker free LED monitors.

The Latest on Computer Screens and Eye Fatigue http://www.eizo.com/global/library/basics/eyestrain/index.html

LED backlight causes eye fatigue?

Since the popularization of LED backlights, the number of people who report eye fatigue caused by flicker has increased. Some people perceive the high speed at which the LED backlight flashes as flicker. Of course, even those who cannot perceive flicker may also be affected by it without realizing it.

How does flicker work?

Dimming (brightness control), is separated into 2 categories: PWM (pulse-width modulation) and DC (direct current).


LED monitors often use PWM. The design is simple and easy to mass produce.



Does flicker really cause eye fatigue?

We conducted an experiment to find out how users felt about viewing variable light.

Source: Kitasato University (Japan), School of Allied Health Sciences (n=10)

Did you perceive flicker?


Did you feel eye fatigue?


Lastly, which was the easiest to view?




At EIZO…

We have developed a hybrid model that combines the pros of PWM and DC dimming.

http://www.eizo.com/global/products/flexscan/ecoview_microsite/easy_on_the_eyes/index.html

Flicker-Free Images

Due to the way brightness is controlled on LED backlights, a small number of people perceive flicker on their screen which causes eye fatigue. The FlexScan EV series utilizes a hybrid solution to regulate brightness and make flicker unperceivable without any drawbacks like compromising color stability.? Availability varies by model.

Lower Blue Light Reduces Eye Fatigue

In the visible light spectrum, blue light has wavelengths adjacent to ultraviolet light. Compared to the factory preset setting of 6,500 K of typical LCD monitors, Paper Mode is closer to the spectral distribution with long reddish wavelengths so it reduces the amount of blue light, a cause of eye fatigue, and helps prevent eyestrain when reading documents. Availability varies by model.

http://www.benq.com/product/monitor/bl2710pt/

BenQ BL2710 World's First Custom-built CAD/CAM Monitor

BenQ BL2710, the first tailored CAD/CAM monitor is the ultimate solution carefully designed to meet all demands of every professional working with PTC, SolidWorks, AutoCAD, Maya or other CAD/CAM software.



Flicker-free

The Flicker-free technology eliminates flickering at all brightness levels and effectively reducing eye fatigue. Conventional LCD screens flicks 200 times per second. Your eyes may not see flickers, but they can certainly feel them. Free your eyes from flickers by switch to CAD/ CAM Monitors and let your eyes do less work while you are working on CAD/ CAM designs.

BenQ currently has 16 ”flicker-free” monitors on the market [Danish article from December 10]: http://www.flatpanels.dk/nyhed.php?subaction=showfull&id=1386661177

Business:
GL2450HT 24” / Full HD
BL912 19“ / 1280x1024
BL2211M 22” / 1680x1050
BL2211TM 22” / 1680x1050
BL2405HT 24” / 1920x1080
BL2411PT 24” / 1920x1080
BL2710PT 27” / 2560x1440

Standard:
GL2023A 19,5” / 1600x900
GW2265M 21,5” / 1920x1080
VW2235H 21,5” / 1920x1080
GW2320 23“ / 1920x1080
GW2760HM 27” / 1920x1080
GW2760HS 27” / 1920x1080
EW2740L 27“ / 1920x1080

Gaming:
XL2411T 24” / 1920x1080
XL2420T 24” / 1920x1080

LG is now jumping on the flicker-free bandwagon along with Eizo and BenQ.


LG INTRODUCES ITS FIRST FLICKER-FREE MONITORS
LG has announced two new ranges of PC monitors that are flicker-free for better viewing comfort. The new MP76 and MP75 IPS-based monitor series also feature LG’s Cinema design with slim bezels.

Eizo and BenQ have both been pushing for flicker-free monitors for some time, as conventional monitors can cause eyestrain and headaches. LG is acknowledging the issue, too, and will start selling “flicker-safe” monitors soon with the MP76 and MP75 models.

Read the rest of the article here: http://www.flatpanelshd.com/news.php?subaction=showfull&id=1390811976


Background article:
LED MONITORS CAN CAUSE HEADACHES DUE TO FLICKER
http://www.flatpanelshd.com/focus.php?subaction=showfull&id=1362457985


LG MP76 press release:
LG UNVEILS PREMIUM MP76 IPS MONITOR WITH STRIKING DESIGN AND SUPERB PICTURE QUALITY
With Clear Stand and Thin Bezel, Stylish MP76 Boasts Full HD IPS Display
and Flicker-SafeTechnology for More Comfortable Viewing Experience
http://www.lgnewsroom.com/newsroom/contents/64140
LG 24MP76HM

[Rigby]

That is interesting.  I've seen gaming monitors which introduce an intentional 120Hz flicker in order to eliminate LCD streaking.  The driver software on the PC runs everything at 120Hz, but every other frame is blank, with the backlight OFF, intentionally.  This, apparently, is very effective in reducing motion blur on LCDs and making LCDs perform more like CRTs in terms of motion blur.

http://www.testufo.com/#test=blackframes&count=2&equalizer=1

[Marco]

Alignment might play a role as well ... 200 Hz does not align with the refresh rate (60 Hz) so you will probably get some low beat frequency like effects.

[AndersAnd]

Be careful with cold light if you often spend time in you lab in the evening.

Cold light (blue-enriched light) greatly suppresses the human bodys production of melatonin and hence affects your sleep if you're exposed to blue-enriched light in the hours before going to sleep.

Recent studies by Centre for Chronobiology at Psychiatric Hospital of the University of Basel, Switzerland among others has shown negative effects on human sleep by exposure to blue-enriched light in the evening. But might also be contributing to a host of diseases.
http://www.chronobiology.ch

Article in New York Times http://www.nytimes.com/2011/07/05/health/05light.html?pagewanted=all&_r=0

In Eyes, a Clock Calibrated by Wavelengths of Light
By LAURA BEIL
Published: July 4, 2011

Just as the ear has two purposes — hearing and telling you which way is up — so does the eye. It receives the input necessary for vision, but the retina also houses a network of sensors that detect the rise and fall of daylight. With light, the body sets its internal clock to a 24-hour cycle regulating an estimated 10 percent of our genes.

The workhorse of this system is the light-sensitive hormone melatonin, which is produced by the body every evening and during the night. Melatonin promotes sleep and alerts a variety of biological processes to the approximate hour of the day.

Light hitting the retina suppresses the production of melatonin — and there lies the rub. In this modern world, our eyes are flooded with light well after dusk, contrary to our evolutionary programming. Scientists are just beginning to understand the potential health consequences. The disruption of circadian cycles may not just be shortchanging our sleep, they have found, but also contributing to a host of diseases.

“Light works as if it’s a drug, except it’s not a drug at all,” said George Brainard, a neurologist at Thomas Jefferson University in Philadelphia and one of the first researchers to study light’s effects on the body’s hormones and circadian rhythms.

Any sort of light can suppress melatonin, but recent experiments have raised novel questions about one type in particular: the blue wavelengths produced by many kinds of energy-efficient light bulbs and electronic gadgets.

Dr. Brainard and other researchers have found that light composed of blue wavelengths slows the release of melatonin with particular effectiveness. Until recently, though, few studies had directly examined how blue-emitting electronics might affect the brain.

So scientists at the University of Basel in Switzerland tried a simple experiment: They asked 13 men to sit before a computer each evening for two weeks before going to bed.

During one week, for five hours every night, the volunteers sat before an old-style fluorescent monitor emitting light composed of several colors from the visible spectrum, though very little blue. Another week, the men sat at screens backlighted by light-emitting diodes, or LEDs. This screen was twice as blue.

“To our surprise, we saw huge differences,” said Christian Cajochen, who heads the Center for Chronobiology at the University of Basel. Melatonin levels in volunteers watching the LED screens took longer to rise at night, compared with when the participants were watching the fluorescent screens, and the deficit persisted throughout the evening.

The subjects also scored higher on tests of memory and cognition after exposure to blue light, Dr. Cajochen and his team reported in the May issue of The Journal of Applied Physiology. While men were able to recall pairs of words flashed across the fluorescent screen about half the time, some scores rose to almost 70 percent when they stared at the LED monitors.

The finding adds to a series of others suggesting, though certainly not proving, that exposure to blue light may keep us more awake and alert, partly by suppressing production of melatonin. An LED screen bright enough and big enough “could be giving you an alert stimulus at a time that will frustrate your body’s ability to go to sleep later,” said Dr. Brainard. “When you turn it off, it doesn’t mean that instantly the alerting effects go away. There’s an underlying biology that’s stimulated.”

Still, nobody is suggesting that we all turn off the lights at dusk and sit in the dark; research into this area is in its infancy. “We are only beginning to understand what really happens under natural conditions,” said Mark Rea of the Lighting Research Center at Rensselaer Polytechnic Institute in New York.

Artificial light has been around for more than 120 years. But the light emitted by older sources, like incandescent bulbs, contains more red wavelengths. The problem now, Dr. Brainard and other researchers fear, is that our world is increasingly illuminated in blue. By one estimate, 1.6 billion new computers, televisions and cellphones were sold last year alone, and incandescent lights are being replaced by more energy-efficient, and often bluer, bulbs.

In January in the journal PLoS One, the University of Basel team also compared the effects of incandescent bulbs to fluorescents modified to emit more blue light. Men exposed to the fluorescent lights produced 40 percent less melatonin than when they were exposed to incandescent bulbs, and they reported feeling more awake an hour after the lights went off.

In addition, the quantity of light necessary to affect melatonin may be much smaller than once thought. In research published in March in The Journal of Clinical Endocrinology and Metabolism, a team at the Harvard Medical School reported that ordinary indoor lighting before bedtime suppressed melatonin in the brain, even delaying production of the hormone for 90 minutes after the lights were off, compared with people exposed to only dim light.

What do these findings mean to everyday life? Some experts believe that any kind of light too late into the evening could have broad health effects, independent of any effect on sleep. For example, a report published last year in the journal PNAS found that mice exposed to light at night gained more weight than those housed in normal light, even though both groups consumed the same number of calories.

Light at night has been examined as a contributor to breast cancer for two decades. While there is still no consensus, enough laboratory and epidemiological studies have supported the idea that in 2007, the World Health Organization declared shift work a probable carcinogen. Body clock disruptions “can alter sleep-activity patterns, suppress melatonin production and disregulate genes involved in tumor development,” the agency concluded.

Blue light’s effects might be particularly pronounced for shift workers and others who get little natural daylight, some researchers say. Consider one small trial that appears the June issue of The Journal of the American Medical Directors Association. Among 28 elderly nursing home residents, those exposed to just 30 minutes of blue light on weekdays for four weeks showed improvement in cognitive abilities, compared with patients exposed only to red.

Researchers like Dr. Brainard hope the science may lead to a new generation of lights and screens designed with wavelengths that adjust according to the hour of the day.

Among those interested are officials at NASA, who have approached the neurologist about designing light on the International Space Station in a way that promotes alertness during waking hours and encourages sleep during times of rest.

“I think we’re on the verge of a lighting revolution,” said Dr. Brainard. If the hormone-sparing lights can be made to work during spaceflight, he said, “people will use it here on the ground.”


A version of this article appeared in print on July 5, 2011, on page D5 of the New York edition with the headline: In Eyes, a Clock Calibrated by Wavelengths of Light.

Acute exposure to evening blue-enriched light impacts on human sleep http://onlinelibrary.wiley.com/doi/10.1111/jsr.12050/abstract

Summary
Light in the short wavelength range (blue light: 446–483 nm) elicits direct effects on human melatonin secretion, alertness and cognitive performance via non-image-forming photoreceptors. However, the impact of blue-enriched polychromatic light on human sleep architecture and sleep electroencephalographic activity remains fairly unknown. In this study we investigated sleep structure and sleep electroencephalographic characteristics of 30 healthy young participants (16 men, 14 women; age range 20–31 years) following 2 h of evening light exposure to polychromatic light at 6500 K, 2500 K and 3000 K. Sleep structure across the first three non-rapid eye movement non-rapid eye movement – rapid eye movement sleep cycles did not differ significantly with respect to the light conditions. All-night non-rapid eye movement sleep electroencephalographic power density indicated that exposure to light at 6500 K resulted in a tendency for less frontal non-rapid eye movement electroencephalographic power density, compared to light at 2500 K and 3000 K. The dynamics of non-rapid eye movement electroencephalographic slow wave activity (2.0–4.0 Hz), a functional index of homeostatic sleep pressure, were such that slow wave activity was reduced significantly during the first sleep cycle after light at 6500 K compared to light at 2500 K and 3000 K, particularly in the frontal derivation. Our data suggest that exposure to blue-enriched polychromatic light at relatively low room light levels impacts upon homeostatic sleep regulation, as indexed by reduction in frontal slow wave activity during the first non-rapid eye movement episode.

Quote from the NY Times article:

Researchers like Dr. Brainard hope the science may lead to a new generation of lights and screens designed with wavelengths that adjust according to the hour of the day.

f.lux is a freeware computer program based on this idea. It runs in the background and automatically adjusts the screen color temperature according to time of the day and your location. It's available for both Windows, Mac, Linux and iOS.

http://en.wikipedia.org/wiki/F.lux
http://justgetflux.com

I've been running f.lux on my laptop for a couple of years. It's a bit weird in the beginning as white backgrounds turns more red during the evening, but you soon get used to it and the transitions happens slowly so you don't notice sudden changes when sitting in front of the screen.
Activating f.lux while doing color sensitive work like graphics and photo/video editing is probably not a good idea. But you can turn it of temporarily. But for most internet browsing, office work, PCB design etc. it's fine.

For Linux there's also Redshift, as an alternative to xflux [f.lux for Linux].

And for Android there's Twilight.

Redshift

Redshift adjusts the color temperature of your screen according to your surroundings. This may help your eyes hurt less if you are working in front of the screen at night. This program is inspired by f.lux (please see this post for the reason why I started this project).

Related software

• Redshift Plasmoid for KDE provides a graphical configuration interface for Redshift.
• Twilight for Android provides a similar application for Android (not open source).
• f.lux is a similar program for Windows/Mac and iPhone/iPad, and there is also a Linux version (not open source).

[michael.hill]

Sorry for reviving an old thread, but I'm thinking about getting some lighting for my workbenches.  I'm thinking of getting these: http://www.homedepot.com/p/Lithonia-Lighting-4-ft-White-T5-Fluorescent-Grow-Light-GRW-2-28-CSW-CO-M4/203407595#certona_recommendations

I have two of these: http://www.homedepot.com/p/Edsal-48-in-W-x-24-in-D-Workbench-with-Storage-MRWB-4/202545413 (which are coincidentally the same as Ben Krasnow's in his fluorescent tube video mentioned earlier).  Any thoughts on using these?

[michael.hill]

I seem to notice people apologising for reviving old threads. I don't see the problem. Am I just too disconnected from the zeitgeist?

Back on topic I think those would provide a good broad diffuse shadow free light. Which I prefer to the harsh shadows and bright spots thrown by small point source LEDs. Good for "pot" plants apparently too.

It's because there's a big warning that shows up when you're about to post in a thread nobody's posted in in 4 months.

Thanks for your thoughts. Btw, there ARE other plants people use these for...(lol yeah right). The only pot these will be used for is looking at a nice Bourns 10-turn knob pot I found.

[Rigby]

(if an old thread is on topic for your problem/question, then i say revive it.  better for future readers, i think, if there's one thread rather than two about the exact same thing.)

T8s are cheaper than T5s, for the reasons Ben mentions in his video.

For my garage workspace, I got T8s, electronic ballasts, and I've been very happy with them.  (the fixtures came with electronic ballasts.)

[antonylex]

I'd suggest using an LED desk lamp or an LED floor lamp, because you don't need any drilling or complicated installation. They're easy to adjust the light angle too, so you usually don't have to worry about the shadow as you do with swing lamps. Just make sure they're bright enough.

As for the color temperature, like someone else mentioned in this thread, theoretically a more blueish shade would keep you more alert and vice versa. However we have very different preferences and perceptions of colors (remember "the dress"?), so something that looks yellowish to one person and makes them feel sleepy may not look that yellowish, and thus doesn't have the same effect to someone else. Also some people don't seem to be affected by light color changes at all. So I guess you only need to care if you're really sensitive to light color. Best bet is to find one that allows you to adjust the color according to your mood/preference/the nature of the job and see how you operate in that light.

For floor lamp, check the Brightech Lightview Pro Magnifier Lamp. Bright, dimmable, have magnifier, multiple color tempt.

For table lamp, I recommend the BenQ eReading Lamp. Bright, dimmable, multiple color temp. The base is huge so if your desk is small you might want to use the clamp instead.

Reviews of the Lightview Pro on Amazon: https://www.amazon.com/Brightech-Light-View-Magnifying-Lamp/dp/B00UW2IRJ2/
Reviews of the BenQ: https://www.hookedtobooks.com/best-desk-lamps/

[rdl]

I have three of these and I'm probably going to buy more.

http://www.homedepot.com/p/Commercial-Electric-3-ft-LED-Black-Shop-Light-54254141/206028863


At only 3 ft. long, they're not as bulky as a fluorescent fixture and weigh very little. I have two in my lab area hanging from hooks that are just screwed into the drywall ceiling. They are nice and bright at 3200 lumens. The 4000K color temperature is a clean white and easy on the eyes. It's not a harsh blue daylight color and there's no greenish tint. My only complaint is the power cord. Because it is meant to be okay for damp locations, the cord is permanently attached and is a thick and heavy cable with 3 prong grounded plug. I'm pretty sure if I cut the cord off it would weigh more than the remaining light fixture.

edit: Here is a picture



Compare to before:

[tggzzz]

I find it very useful to have light where I want it at the angle I want it - and to be able to change it until it is just right. Hence I like small gooseneck luminaires which I can grab and twist into the right location.

I have a £25 Ikea Tived bolted to the back of the desk, and it works well.
http://www.ikea.com/gb/en/products/lighting/wall-lights/tived-led-wall-clamp-spotlight-nickel-plated-art-10169692/
The diameter of the head is around 4cm.

[mtdoc]

I have three of these and I'm probably going to buy more.

http://www.homedepot.com/p/Commercial-Electric-3-ft-LED-Black-Shop-Light-54254141/206028863

Those look like a good deal! 

And I am impressed with their magic light units and power generating properties:

Produces 64 watts of light using only 42 watts of electricity