...........i am disappointed and hurt, i thought thiojoe recognized my quirkyness and thirst for knowledge but instead it was just a lewd image site joking, this scam has been going around all of the big channels, does your spectrum analizer handle anything outside of visible??
🔥HELLO🔥 I spent a ton of extra time on this video, so please give an OVERSIZED THUMBS UP 👍 if you enjoyed it, to tell the algorithm that the video doesn't suck
For windows 10 there is a setting called "Night Light" which redshifts your screen to however you have it configured, you can even have it turn on with a schedule.
@@StolenJoker84 f.lux can go much lower than Night Shift when it comes to color temperatures. I know that I prefer to use f.lux instead of Night Shift on my Mac at night because it's easier on the eyes. Unfortunately f.lux is not available on iOS.
FYI, this feature is also available on Linux desktop environnements
2 роки тому+3
@@Jellykrop It's not very flexible as compared to f.lux. I've used Windows night light for a couple of years, and am considering going back. The Windows one doesn't go particularly warm on the colors and you don't have much control over when and how quickly the color shifts.
Ages ago, when there were incandescent bulbs an exotic bulbs, I installed two 8' long high CRI bulbs for color matching. My housemates thought it was crazy, harsh too blue. One night we'd been sitting in my room for an hour, and when my housemate opened the door and looked down the hall, his immediate reaction was "What's wrong with the lights? They're all dim and yellow!" Amazing how the eye acclimates and fools the brain.
Ive been using the "night mode" filter in my computers and phones for years. Windows 10 has it built it. I just got new glasses with transition lenses and they have a very slight blue light filter as well, alot like those clear lenses. It does help warm things up enough that bright lights dont bother me as much anymore
@@653j521 i do have anti-glare as well but they also transition to sunglasses in the sun. Part of the new transition coating gives them a very slight blue light blocker that gives the world around me a very slight yellow tinge. Like whites are slightly off white through them.
I have the same thing on my glasses, and, if they’re sitting on a table or counter and you look at them in the right light, you can actually see that the lenses are slightly yellow.
If you look through them at a white surface you can notice it too. It mainly keeps my eyes from bugging me when in in a brightly lit room or stare at a bright screen. I work at a computer all day which keeping the blue light filter on my computer and these glasses, while not much, help immensely by the end of a day.
I have used gunnars for years since I work in IT. They have prescription options on their web site. The lens are shaped differently than most glasses, they are rounded and moved closer to the eye. When you look at a screen for whatever reason you don't blink as much and your eyes dry out. They shape and the fact that it is closer help reduce evaporation off the eye. I know some of their frames are made to play nicer with headphones, so if you have big cans they don't end of giving you a headache.
What the artist intended would necessarily include what the light source he was using when painting. We cannot assume he/she worked with true light rather than light that had an affected source. Maybe they worked under flourescent lights or by oil lamps.
Yea I just made the same observation and comment. Because we don't know the light source when painting we can't really appreciate the correct color as perceived by the artist. We can put it in an ideal light source, but he may have painted it under florescent so the colors to him would be different then the colors displayed. It's an interesting issue to think about.
@@newmonengineering and this is assuming that the color/pigments do not age, which they do. This is one of the reason why flash light photography is disliked by museums.
Neat! Could you maybe measure the EnChroma glasses which supposedly help with color blindness with this? I wonder if they have a narrow notch filter where the red and green photoreceptor cell responses overlap the most (which I could imagine actually helping) or whether they just arbitrarily tint the picture (which I suppose would just move the range of colors your eyes fail to distinguish).
Truck driver here. I have a pair of prescription "blue blockers" that I wear while driving at night. For me they make a huge difference in blocking the bright blue LEDs on cars. Especially cheap aftermarket ones.
My father was a pioneer of modern spectrometry following WW2. After he left the Navy, he worked in the Ford Motor Research Lab in Deaborn, MI, for 36 years. Wish I had a fraction of his scientific chops!
Far more important than blocking blue light is actually having a proper prescription on the lenses for computer use. By using glasses with roughly +1 diopter from your long distance prescription, you can have the focus of your monitor be at the point where your eye muscles are fully relaxed, which will greatly reduce eye fatigue and can even stop progression of nearsightedness. Your optometrist can help you get the correct prescription for your computer glasses. It can be a bit confusing, because your long distance prescription might be -2.0 diopters, so when you add 1.0 diopters, the resulting prescription is -1.0 diopters and not -3.0 diopters. Depending on your monitor distance, +0.75 or +1.25 offset may be better. It is better to under shoot and go for the +0.75 than to overshoot, because it will be blurry if you go too high.
@@yahm0n Yes, it's basically hollow and amounts to "No". I wrote another comment on this video but since youtube hides and deletes comments with links, I can't link it here. I suppose I can just copy it instead. " Color spectrum and the character of the field (flicker/square wave modulated, point source or diffuse, coherence, intensity, etc) are strongly biologically active. The "blue light hazard" usually brings to mind arc welding, bright stage lights, lightning, etc, but modern data shows blue light even at domestic levels (especially at night) destroys the photoreceptors in our eyes and their associated ganglion downstream of oxidative stress (eg retinal turned into ROS). The observation that light and color affect mood and brain activity is ancient, specific findings go back to Ptolemy who found flashing colors from minerals thrown in a fire would alter mood, and Apuleis who found that flickering lights eg from a spinning spoked potter's wheel could trigger seizures and other mental changes. Cold war research (see Controlled Offensive Behavior: USSR) found that red light disturbed alpha rhythm and caused irritability. Green was stablizing and modulatory. Blue had an exhaustive and suppressive effect on the mind, it was draining. Yellow improved work and sense of wellbeing. Plant growth can be modulated by magnetic fields and visible light spectrum. Lastly, being exposed to intense blue light outside the window of time when it would naturally come from the sun, disrupts circadian rhythm, causes neurodegeneration, and promotes cancer. I strongly recommend wearing yellow shades for night driving. Those bright white LED headlights are not only obnoxious and blind you, they actually cause retinal damage. Flickering LEDs (square wave modulation essentially) cause shockwaves to propagate through the eye. See eg the 1960's FDA symposium on phototherapy for a paper on that, though probably a lot of work has been done since then. LED monitors may also cause retinal damage. LED backlit LCD panels aren't good if they're bright and you're looking at a lot of blue, but overall they're nowhere near as bad. So far only France has issued warnings last I knew, and recognized these risks, even they've been well established in the literature for a long time. "
@@Acetyl53 I like your long statement much better. On the subject of computer glasses though, the computer can reduce the blue light for you before it even leaves your monitor, so wearing glasses for that purpose is an unnecessary discomfort. The computer can't refocus the image, however, so you actually need glasses for that purpose.
@@yahm0n Yeah, I use f.lux and others, but sometimes just putting on yellow glasses is more effective because there is a general trend of putting blue lights on literally everything. The num caps scroll lock lights on my keyboard, until I taped over them with a few layers of masking tape, were an intense blinding blue. They're still a bit too bright, but better. Speakers, same deal, intense blue ring around the volume knob to show they're on, have to cover it with something. And so on. In urban environments you'll also have LED streetlights and various other sources. So it really is everywhere, not just the screens.
Just as a tip, you would get a much more accurate match between light sources by measuring the xy chromaticity coordinates (which your spectrometer does) and inputting the desired value in the light source (if the light source permits). This is for both white & rgb light sources.
@@Iam2lazy2register A really cheap one would be your phone's camera on raw mode. You can use a spectrometer to calibrate it one time and then you'll have a LUT.
@@HAWXLEADER i don't think this would help. The camera sensor can only read distinct primary colors. for example if the red and blue pixels are triggert it has no idea if it sees red and blue light at the same time or perhaps a single violet light
@@cookednick I appreciate your answer, however I have to respectfully disagree. I think you are aware that "violet" light is not the same as simply adding "red" and "blue" light in terms of physics. Only our eyes (and cameras) can not tell the difference between those two scenarios. A spectrometer does exactly that: I measures the intensity of rays of each frequency separately of a given electromagnetic spectrum (typically a bit more then the visible light).
Warning Be careful about these glasses and driving. I once made the mistake of wearing some very expensive fishing and golfing glasses while driving and nearly rear ended a cop car with the lights going . The glasses completely blocked the red and blue and brake lights.
I'm betting they were polarized glasses, my dad always used them to see fish in the water. Maybe it blocked the flashes from the police car in the same way it does with water reflections?
@@cakobjoker8134 . They were polarised, blue blocker with a dark red brown lens and cost more than Bole glasses. They were extremely good but unfortunately too good for driving.
Really interesting stuff. I like how you have expanded the scope of your vids. You do a great job of summarizing and presenting sometimes complex (or could be much more complex) subjects.
If your monitor "sears" your eyes...just turn down the brightness. Most people run their monitors far too bright. This is especially important if you work with a white background (like word processing, spreadsheets, email, etc.). It's really simple to do in display settings. I run my Asus laptop at a brightness of 17 on a 0-100 scale and my external monitor at 50. Looks great and plenty of detail. If I'm editing photos I turn it up a bit. And Windows 11 (10 too) comes with a Night Light feature that turns down the blue cast. You can keep it on 24 hours a day, if you'd like. I don't use that, but it's there if you want it. No need to buy glasses or use a separate app.
yoooooo this is spectacular, i already spent a lot of time in your channel, but just now i realized it was all done by you (is pretty common to extract the info and the content you prefer rather than the person itself) so yeah, what a Great video.
Many people in photography use this device. A cheap alternative is to just use a white balance card to balance your colors, but the tlci index rating is very important when buying light bulbs for video or photography.
I'm working with LEDs in my DIY projects right now and your video gives me a lot of keys for working out the questions I had about how I could try to create a good quality of light. I don't know how easy it would be dor a DIYer to find good individual LEDs and tune them, either with physical filters and/or by tuning the intensity of individually different hues, but it is a very fun exploration project I'm in right now and your video falls at the perfect right moment for me. Many thanks!
Great video, the Light quality part is my favorite! Such an important aspect of artificial lighting which so few are aware about, especially now that incandescent bulbs are completely replaced by LED's, many times being cheap, bad quality. I wonder if those really low CRI, high color temp (worst combo IMO) LEDs can actually affect someone's health.
"I wonder what the weather is like today?" "Please, allow ME. Close your eyes, though" ~holds spectrometer out the window" "It's Yellow out there, you're welcome" ~drops device like a mic, but, catches it last second because it cost $1600~
Man this video was excellent!! From a filmmaker/photographer's perspective.. from a tech enthusiast's perspective.. from a "I used to really like science in school" guy's perspective!! Man great vid, nice job!
I love that you made this video since a couple months ago I notice my gf and roomate’s blue light blocking glasses were crystal clear. They didn’t have any perceivable shift in color, seems very likely if they worked at all there’s no way it’s going to help their circadian ruthenium
Personally, I have a small correction about sodium lamps vs LED lamps. You'll find in places where weather factors can cause reliability issues, you will still see 100% sodium lamps. LED lamps have trouble coping with brutally cold weather as I recall, while sodium lamps are practically bulletproof.
Interesting, never been personally bothered by blue light, although I do have trouble reading bright blue LED displays. If your monitor is too bright, turn it down - is my first thought. I find it rather strange these days, all this talk about blue light being bad, at the same time lots of products being released - like bedside clocks with blue lights. - nuts. (or blue PC case lights)
It's this sort of myth that is used to scare customers into buying products. All research done on blue light is either inconclusive or cannot prove any correlation of "blue" light affecting sleep patterns and/or being bad in general. The presence of artificial lights CAN affect the circadian rhythm, but that's all light in general, independent of the hue. The only good use of the blue filters we have in our devices is that by making screens appear more red we reduce their apparent brightness, which is good if you don't want to be blinded every time you look at your phone in the evening.
That and they don't bother with a proper value of resistor, so they're not just blue lights, they're brighter than the sun itself. I had to tape over the back of my PC's wifi card because it just constantly strobes a blinding blue light for some reason.
Thanks for testing flux with the tool, I was wondering how useful it actually was for late night reading. I'm so happy to see that at the highest settings it does almost completely remove blue light!
Those almost-clear lenses are just like the blue-blocking coating my eye doctor recommended for my new prescription computer glasses. Looks like it should've instead been applied to my driving glasses. "blue-blocking" doesn't necessarily mean all of the color blue that you see, but those shorter blue wavelengths which transfer more energy. Things that react to UV light will also react to the higher blue frequencies as well, and you can use some types of blue LEDs to charge phosphorescent compounds. So if the goal is to block the frequencies which slowly destroy your eyes, those almost-clear glasses look like they'll be very effective.
This video is very good, a complex subject. I used to be in charge of a color matching lab. A customer would want our product to match a color of something of a completely different material. A very difficult job indeed but they want a match. We used a light source that had the capability of showing sunlight, fluorescent light, and incandescent light, all before LED's or other choices. I am now at a church with the goal of saving money on power bills and changing to LED's is a great idea but some folks want the incandescent color back cause something looks different.
I know a few people who don’t like the look of “Daylight” bulbs. I prefer them. IMO, everything looks better with them. I don’t like the look of yellowish bulbs.
I have computer glasses. Same price for one as the double pack you bought, have a slight tint to them. My goodness is the effect noticeable. It doesn't seem to have much of an effect on the colors I see, but the eye strain is just... gone. It improved my sight, too, because of the lack of eye strain. At work, we're not exactly allowed to be installing our own programs. I use Window's night light feature, but it still doesn't help as much as one might hope, especially because of the fluorescent lights (which may have some effect with UV blocking). At home, I use f.lux and I'm glad to see it getting the praise it deserves.
Pure red lights are used instead of regular lighting with closely confined chickens. If any birds happens to get a bleeding injury, others tend to peck at them under normal lighting. Chickens won't peck at what they can't see however.
@@trei2unu I had seen that in a science book from the 70's Seems the lighting was more workable in the end. I suppose you could GMO a color-blind fowl these days.
It is interesting we call 1-3 k as warm, but it is actually way colder than blue (so called cold light) emitted by object way way hotter than (so called warm) one.
Speaking of light quality, CRI, and TM-30.. maybe do a video where you grab one of each brand/model of light bulb at a local hardware store or various ones off Amazon or whatever, and see which ones perform the best with the better CRI/TM-30 :P Can be especially useful for those who want good quality lighting on the cheap (who can't afford proper filming lighting yet), or simply those who just want good color accurate room lighting that can also double as filming light.
I'm really curious about why magenta and green... I work with aircraft avionics and we use those colors a LOT to denote different sources of data. Magenta usually means GPS / FMS (Flight Management System) whereas green indicates a Nav Radio source, and the pilots can flip between these nav sources. There has to be some reason these colors became the standard, right?
Most of the "yellow" street lights are actually high pressure sodium lights, not low pressure. High pressure widens the spectrum from that monochrome orange to something noticably better. Low pressure sodium isn't really used anywhere except places that need that precise sliver of spectrum, like near some ground telescopes so they can filter out the light pollution without removing much detail.
Regarding your remark around 11:54 where it seems that the "Amber" lenses are more effective with the screen, you are right about the levels. The lenses are dampening the level based on a percentage, thus the first example it is around 1.3 / 0.45 = 2.89x damping, and in the computer screen it is around 13 / 5 = 2.6. If we could read it out correctly, I would assume that these numbers are the same, so actually it dampens the same. For these things it is good to plot the values in dB-units (or just logarithmic scaling), as it is better to compare, especially with the true blockers as the curve goes to zero. An even more intuitive way would be to divide the two lines over each other and take the log so you get the optical density (OD), this is common for blocking glasses like for lasers.
Blue-light glasses are silly with computer monitors because each pixel literally has a controllable blue filter in it (or controllable blue level with something like OLED). The test of whether you have blue is how white looks. If it looks orange/reddish, then you're reducing blue. The benefit of blocking glasses is just that you have one place you can reduce blue from *everything* you look at, rather than having to adjust things in the environment (each computing device, light bulbs). And if you're going to get blockers, makes sense to get the extreme ones he shows. Go all the way and make sleep a priority.
A bit of a backstory on Low Pressure Sodium lighting. They were used to reduce light pollution. Astronomers can use a Neodymium Filter to kill that one narrow spike of yellow light and their astronomical photos then are not washed out.
for the monitor, use the night mode feature that windows have. (don't need to have it full strenght) edit: it does the exact same thing as F.lux but it is already on your pc
Personally, I just prefer going into my monitors settings and turning down the blue LEDs if I need to have less blue light. Actually I'm quite surprised you didn't mention that, despite most if not all monitors having the option. Then there's also the "night light" mode in windows, that turns down the blue light LEDs for an easy toggle switch.
This is an incident light meter, reflected light will depend on the colour of the object. Photography mostly uses reflected light. There is a different measurement for printers which rely on reflected colour compared to monitors which radiate light.
I wear corrective glasses all the time, and I've always ordered mine with the coatings for screen protection and glare protection for drivers, since I work on a computer, and I also drive regularly. However that makes them really expensive. Over 200 euro per lens, and that doesn't include the frame or the work to cut and fit it into the frame.
Quick thought on blue light blocking glasses: People who are using graphics and need to see the colors can take off and put back on the glasses easier than switching the software on or off. Of course, if the need to examine colors is infrequent, it may be better to save money on the glasses and fiddle with the software on those rare occasions.
this whole video was GREAT, exactly the kind of thing I wanted to know about, which was delivered to me in an easily digestible format, as I was too busy/lazy to go read about it all myself.
Would those light spikes explain why I had to return those bulbs? I tried using the Hue bulbs and they just hurt my eyes no matter the brightness or colour.
This video brought me to an interesting thought experiment. You said that the painting may not look right under the incorrect light but the fascinating thing here is, we don't know what light the artist used when he created the art so the true color to the artist while painting it, could be radically different looking under an ideal light source if he painted it under say a florescent bulb. So we will never get the true painting colors as intended by the artist because the actual colors he saw when painting may be different under a better light source.
20:12 Why 99 colors? Seams like 100 would be a nice & round number? Or is it some bullshit like with prices in stores, where eg. $14.99 "looks" cheaper than $15.0 ?
Just a guess, but 99 is easily divisible by 3 so it can be used for rgb, where 100 is not easily divisible by 3 and can mess up rgb colors or make them more challenging to produce with the 3 different values used in rgb. 🤷♂️
Interesting. I recently bought new glasses, on my old ones i had no blue light filter. I work in IT so i sit in front of computer all the time. My new lenses have blue light filter and it definetly helps. They are made by Carl Zeiss block 30% of the blue light and are completely clear - the filter is in the lense itself, no extra layer with blueish/pinkish color. (most common filters block around 15% of blue light and have tint).
There is art light bulbs. Bulbs designed for placement above paintings. As for different light source different effects on the color of different items. Get your girl’s nails done, tell her beauty is pain, and without sacrifice, then there can be no large gain. Now, look at the difference under different light sources. You can see for example one color could be a bright almost neon hot pink, but it will shift it a deep berry almost red. It’s like that for all colors, some more extreme than others.
Thank you so much for this detailed analysis. I’m curious: what would RGB, RGBW, RGBWW lights look like under spectroscopy? Especially when imitating daylight and the warm light of an incandescent bulb? A cursory query didn’t reveal anything of note. Additionally, what light bulbs or sources would most accurately follow the daylight spectrum? This is an incredibly interesting topic for me. For example, what (or how significant is the) impact does the painting of a room have? What about early lighting sources such as fires from firewood or oils or or or? Do CRTs have the same spectroscopy results as an LED monitor? If anyone has any recommendations on information sources for any of these topics, please let me know. It’s really quite fascinating. Thank you again for the video! 👍🏻👍🏻👍🏻
I can't comment for the incandescent under spectroscopy, but a traditional incandescent bulb (and Halogen bulbs, if I'm not mistaken) have a CRI of 1. This is because both sources are black-body radiators, and emit full-spectrum light. Imitating daylight with these sources is just a matter of applying a gel, which essentially acts as a modifier for the base XY chromacity coordinates. To emulate daylight, the traditional way to do it is using a type of light called an HMI. These have a CRI of approx 90+, so are generally regarded as having good colour reproduction. However, it's worth noting that more modern professional-grade (real professional grade, not just whatever the packaging says!) LEDs can achieve a CRI of 95, and have been getting more popular as they have much lower power requirements and weight than a comparable HMI for the same level of output. Another bonus for LEDs, is that for large panels may not need any additional diffusion as their "source" is larger. Not 100% sure about the fire stuff, but I'd assume they would also have a CRI of 1 as they are again, black-body radiators.
He showed RGB lights at one point in the video; it basically has 3 peaks for R, G, and B. RGBW means that there's an additional broad-spectrum (white) emitter. The exact shape of the spectrum emitted by the white channel depends on how it's generated, but overall you would see R, G, and B peaks overlaid on the W channel's spread-out curve.
Random pedantic point, there is no such thing as an "intrinsic color" of an object. A reference illuminant (e.g. D65) is always needed to derive the final color appearance. So something that "is a red object" is generally assumed to "appear red under a set of illuminants."
The Phillips hue having red and green for yellow is due to it using RGB LEDs. When outeues pick up multiple colors of light from 1 source or reflection, our brains process it as the color between the 2 on the spectrum. Since there's no yellow LED being used, green and red light are used for that effect. You'll see blue and green for cyan for example
Would love to see you using a spectrometer against window tint that claims to block UV. I’m pretty sure that they only block a narrow band but would love to see how they actually perform
The first set of glasses might make more of a difference with older LCD monitors that still have a CCFL backlight instead of an LED one. Those probably do still put out some (ultra)violet light.
I am very picky when shopping for lights; specifically due to chronic migraines. Now, I am aware not everyone has their migraines triggered by light and mine have been diagnosed as triggered by a combining effect. But, I think light quality as well as temperature is very important for those who may suffer from frequent or non-frequent migraines. Now, here's the kicker - Everyone reacts to light frequency differently when it comes to what temperature may or may not trigger a migraine. As an example I wear sunglasses in almost any building which uses Fluorescent lights. This is due to a few reasons and the biggest being the frequency of said fluorescent light. The 2 most common being 50hz and 60hz. So, these are some things to think about among all the good and useful information received here. Definitely see your doctor though if you suffer from migraines. Cheers! Stay Healthy and Stay Sane!
a trick is to take a prism , or even a 'rainbow sparkle' type decorative/gift wrap paper , up to the light that way, you will see the colour from the light broken down into its individual components, 'showing its true colours' so to speak a terrible CFL light would look like discrete blue and yellow segments, an RGB light would look like individual coloured dots ... but an incandescent or high CRI bulb would give a rich and continuous spectrum
The reason some cities use the Yellow Sodium Vapor lamps are to reduce light pollution near an observatory, in which it is easy to filter out a narrow band of light from the surrounding area.
You can find these for about four hundred, a quarter price from apogee instruments, who educates at Utah State, bro... pro grower here, many herb farmers use these with led now as a must have tool.
There's one more thing about light quality that you didn't mention in the video: PWM/pulsation/whatever you call it. Not every PWM is bad (eg 5kHz is most likely doesn't have any effect on a person).
Another alternative to blue-blocker computer glasses and/or spectrum settings, when viewing computer monitors: change the display setting from light mode to dark mode. Then, you'll have small amounts of brightness against a dark background.
Are there any "daylight" lamps (or lamp assemblies) that actually do a good job of reproducing a full sunlight spectrum at sea level, including into UV and NIR, and without the spectra dips and spikes, like those at 455 and 485, that are not in real sunlight?
I think there are, at least in the Pro lighting field. Arri for instance. But IIRC these are expensive, power hungry devices that use some form of incandescent light source, which as explained in the video do give a (close to) true black body curve similar to actual sunlight. Anything based on LEDs basically uses multiple colors balanced to "look like" actual sunlight, but as you can clearly see on his spectrometer, does this by mixing R,G and B to produce white.
20:00 I found this part confusing because it suddenly starts talking about perceptual colors, whereas the rest of the video is about light at different wavelengths, without noting or explaining the distinction. When talking about colors as defined by wavelengths, the spectrum of a light source can't cause the colors to change saturation or shift in hue, as each wavelength is either absorbed or reflected/transmitted (to a first approximation, unless you're pointing the light at a phosphor or something).
You should have tested the blue light reduction feature in windows to see if it gets the same results. Personally I own different blue light reduction glasses with varying intensity, I only use them when my eyes are in pain. It helps a lot.
TL;DR: I'm a nerd when it comes to colorspaces and the math behind color science, and this video is one of the few I've seen which is Actually Good. I have no idea what other content you make, but I'll be watching it even if only to see a 'known good' reference for color reproduction in video, so I've subscribed (and of course I liked the video). I have one tiny complaint, which is not at all your fault. I've been messing with colorspace conversion code for several years now as a hobby to satisfy some curiosities of mine, and a while back I finally broke down and bought a cheap colorimeter online so I could test my code. I'd like a spectrometer as well, but can't afford one (especially not while unemployed). Throughout the process, I've seen many UA-cam videos which try to 'explain' color science in various ways, but get it horribly awfully wrong in extremely important ways. So now I happened to see this video, with a thumbnail showing the sort of tool I've been wanting but can't afford, and that made me curious enough to watch... ... And despite the video not being about the device or color science specifically (according to the title, at least), you spend the first seven minutes - and the last eight and a half minutes - talking about it while NOT getting anything wrong! This felt almost (though not quite) like looking into some alternate Universe, and watching myself make a video about some specific thing but quickly devolving into a big long tangent about why color science is so cool. Heck, the only reason why I've NOT made such a video is because I don't know how to constrain the scope very well, and would likely spend two hours rambling about how strange it is that nobody performs L*a*b* conversions using matrices and parametric gamma correction functions despite those being literally all that's needed. I even learned something NEW from your video, as I hadn't previously heard about TM-30! Looking into it, Wikipedia seems like it Used to have a dedicated article for it, but it's since been merged into an article just called 'Color rendering'. This is awful, but at least in the references there's a link to a long paper that goes through it at a high level.. But unfortunately doesn't give any of the specifics for the math. I'm starting to get the feeling that this is another standard that you need to purchase a copy of to get the actual technical details, which sucks when you want to fiddle with it by writing code and you don't have a way of actually using it in real life. In particular though, TM-30 looks a lot like a more mathematically rigorously engineered version of the 'Farnsworth-Munsell 100 Hue' color blindness test. Color blindness simulation is one of the things I've tinkered with and have an interest in, and I imagine TM-30 can be used to better-standardize the testing conditions, and maybe even formulate a better set of color swatches (or even directly act as the set of color swatches to use). There is only one thing in your video that was teechnically 'wrong', but is in no way your fault. The 'spectrum' graphs that are colored in to show which parts of the spectrum correspond with which visible colors, including the graphs shown on the screen of your device, are completely bogus and do not at all represent the correct hues whatsoever. For an overview of why, there's a great article on the San Diego State University website that is simply titled 'Rendering Spectra'.
14:10 there is actually built in feature on windows 10 (i don't know there is on windows 11) called night light. it makes your computer monitor bit orange, reducing blue light on your monitor
Me watching this video with Night Mode filters on: Ah yes, the color reproduction is crucial! Fun fact, a quick test for dirty LED light is to turn on your phone camera, and hold it up to the light bulb - once it adjusts to the brightness of the light source, your phone display will slightly separate out the differences in R G and B spectrums in a way similar to interlacing. The update rate of the display and shutter catch different pulses of light from each LED. This obviously doesn't happen with blackbody light sources.
I alwa,s thought CRI is suboptimal because it compares to a standard incadescent bulb. Would like a comparison to sunlight on a defined latitude. TM-30 might also alow a recalculation to better match the sunlight at your location.
Good point, but the advantage of comparing against black-body spectra is that it makes the index depend purely on an absolute physical phenomenon which is the same everywhere. The spectrum of sunlight can only be determined empirically, as it gets filtered through the atmosphere, and thus the spectrum as seen from the ground depends on many factors (latitude, angle of sun/time of day, season, altitude, cloud cover, humidity, atmospheric dust concentration and composition, ozone hole, ...). So basing it on sunlight would require arbitrarily picking some "standard" sunlight spectrum.
@@fat_pigeon You are absolutely right, and i don't know if i have a better suggestion, but having incadescent defined as ultimate best just seems wrong. In University we had a wall of many boxes with reference colour sheets, some of the same objects and a different kind of light source in the box. Only few mostly older people picked the incadescent as "best" light. I would mostly pick bulbs marceted as "neutral" around 4000k as prefered source.
Yeah I read a lot of the comments and people are a little weird.. To say at least I think you did a fantastic video a lot of people don't know anything about blue light what it does to your sleep cycles your eyes the nerves in the back of your eyes.I think you did a great job. It's interesting most people don't know anything about it and just giving us an overview is that educational, Most of your videos are by the way, I loved your old Gaming videos there are awesome right up there with the green haired guy without the screaming but I still love watching him Jackaboy. Anyway love your vids keep it up.I like the way you put them at the side at the end of the video. Alot of creators don't. So we can pop into the next video without having to click around. Thanks Joe.!.!
Why would you need to block ALL blue light at night? it's still nice to have things in full color when getting ready to sleep, isn't toning down the blue enough?
I'm not certain but from what I recall, the brain is quite sensitive to the presence of blue light at all for setting circadian rhythms, so if you attenuate blue light only by (say) 50% you wouldn't get that much benefit.
Hi there! My PC glasses are not as yellow as those you show but also not as water clean as that :) what you show. It is a thing in between. I did not test them but I can tell that they are 100% doing what are they supposed to do. Means I am able to sleep better. Great video
Out of curiosity I looked for the CRI rating of the LED bulbs I have here. Interestingly the cheap ones from Aldi claim a rating of 90, while the ones from Philips only have a rating of 80. So it doesn't seem to be related to price that much. Given how small and hidden both ratings were, they are well aware, that most customers don't care about that.
I have a slight prescription and we added a bluelight filter making the glasses a bit yellow (a bit more yellow than the clear ones). In my case, they do take the edge off, and if I'm honest, I don't see any difference between them and my Gunnar Ambers (65%).
If you want a super cheap option for a spectrometer and you know a bit of electronics get yourself an Arduino and a AS7262 spectrometer chip, perfect for testing glasses...cheers.
@@arisoda I tried a few tests but I dont have any glasses that block anything specific ! It should give a very course rough test, of course nothing like what Joe's kit can do, but you will see if the blue end is blocked or the red end so I guess it will tell you if a pair of eBay specs are doing what they claim!...cheers.
@@andymouse couldn't you just as easily test that by using a red or blue piece of translucent plastic? So for example, if you want to test glasses for blue-filtering capability, you place something blue translucent behind it and see whether you see any light at all. If you see blue light, then the glasses work. I think this would work because colored plastics will absorb every color except the color of that plastic
⚠️IMPERSONATION SCAM ALERT⚠️
If you received a comment telling you to contact "me" on telegram, instagram, whatsapp or anywhere else, it is a SCAM!
alright
No shit Sherlock. I don't think this needed a video.
aight
...........i am disappointed and hurt, i thought thiojoe recognized my quirkyness and thirst for knowledge but instead it was just a lewd image site
joking, this scam has been going around all of the big channels, does your spectrum analizer handle anything outside of visible??
Windows 11 has the flux feature built-in now.
🔥HELLO🔥 I spent a ton of extra time on this video, so please give an OVERSIZED THUMBS UP 👍 if you enjoyed it, to tell the algorithm that the video doesn't suck
gaget
There is cheaper brands by apogee and migro, cheers
@@Kat21 gajett
Would you recommend LG 27 GP850 in 2022 as a Main monitor for Entertainment?
Your videos are always worth a Like. Thanks for the time and effort for the videos
For windows 10 there is a setting called "Night Light" which redshifts your screen to however you have it configured, you can even have it turn on with a schedule.
I would be interested to know how well this works compared to f.flux
I don’t use the “Night Light” feature on my computer, but I do use “Night Shift” on my phone.
Regarding f.lux, don’t they do the same thing?
@@StolenJoker84 f.lux can go much lower than Night Shift when it comes to color temperatures. I know that I prefer to use f.lux instead of Night Shift on my Mac at night because it's easier on the eyes. Unfortunately f.lux is not available on iOS.
FYI, this feature is also available on Linux desktop environnements
@@Jellykrop It's not very flexible as compared to f.lux. I've used Windows night light for a couple of years, and am considering going back. The Windows one doesn't go particularly warm on the colors and you don't have much control over when and how quickly the color shifts.
Ages ago, when there were incandescent bulbs an exotic bulbs, I installed two 8' long high CRI bulbs for color matching. My housemates thought it was crazy, harsh too blue. One night we'd been sitting in my room for an hour, and when my housemate opened the door and looked down the hall, his immediate reaction was "What's wrong with the lights? They're all dim and yellow!"
Amazing how the eye acclimates and fools the brain.
Ive been using the "night mode" filter in my computers and phones for years. Windows 10 has it built it. I just got new glasses with transition lenses and they have a very slight blue light filter as well, alot like those clear lenses. It does help warm things up enough that bright lights dont bother me as much anymore
Like anti-glare?
@@653j521 i do have anti-glare as well but they also transition to sunglasses in the sun. Part of the new transition coating gives them a very slight blue light blocker that gives the world around me a very slight yellow tinge. Like whites are slightly off white through them.
I have the same thing on my glasses, and, if they’re sitting on a table or counter and you look at them in the right light, you can actually see that the lenses are slightly yellow.
If you look through them at a white surface you can notice it too. It mainly keeps my eyes from bugging me when in in a brightly lit room or stare at a bright screen. I work at a computer all day which keeping the blue light filter on my computer and these glasses, while not much, help immensely by the end of a day.
I have used gunnars for years since I work in IT.
They have prescription options on their web site.
The lens are shaped differently than most glasses, they are rounded and moved closer to the eye. When you look at a screen for whatever reason you don't blink as much and your eyes dry out. They shape and the fact that it is closer help reduce evaporation off the eye.
I know some of their frames are made to play nicer with headphones, so if you have big cans they don't end of giving you a headache.
What the artist intended would necessarily include what the light source he was using when painting. We cannot assume he/she worked with true light rather than light that had an affected source. Maybe they worked under flourescent lights or by oil lamps.
Or indeed, the artist had cataracts. :)
Yea I just made the same observation and comment. Because we don't know the light source when painting we can't really appreciate the correct color as perceived by the artist. We can put it in an ideal light source, but he may have painted it under florescent so the colors to him would be different then the colors displayed. It's an interesting issue to think about.
@@newmonengineering and this is assuming that the color/pigments do not age, which they do. This is one of the reason why flash light photography is disliked by museums.
*they
Neat! Could you maybe measure the EnChroma glasses which supposedly help with color blindness with this?
I wonder if they have a narrow notch filter where the red and green photoreceptor cell responses overlap the most (which I could imagine actually helping) or whether they just arbitrarily tint the picture (which I suppose would just move the range of colors your eyes fail to distinguish).
Hm interesting idea
@@ThioJoe I second this idea.
@@ThioJoe would make a great informational video!
I guess I want to say that "You don't know what you don't know" and I didn't realize the depth of what I don't know...it's a lot! Thanks!
Truck driver here. I have a pair of prescription "blue blockers" that I wear while driving at night. For me they make a huge difference in blocking the bright blue LEDs on cars. Especially cheap aftermarket ones.
My father was a pioneer of modern spectrometry following WW2. After he left the Navy, he worked in the Ford Motor Research Lab in Deaborn, MI, for 36 years. Wish I had a fraction of his scientific chops!
Far more important than blocking blue light is actually having a proper prescription on the lenses for computer use. By using glasses with roughly +1 diopter from your long distance prescription, you can have the focus of your monitor be at the point where your eye muscles are fully relaxed, which will greatly reduce eye fatigue and can even stop progression of nearsightedness. Your optometrist can help you get the correct prescription for your computer glasses. It can be a bit confusing, because your long distance prescription might be -2.0 diopters, so when you add 1.0 diopters, the resulting prescription is -1.0 diopters and not -3.0 diopters. Depending on your monitor distance, +0.75 or +1.25 offset may be better. It is better to under shoot and go for the +0.75 than to overshoot, because it will be blurry if you go too high.
I don't agree that one is more important than the other, though I'd say blue light is more important if anything.
@@Acetyl53 That's a pretty weak stance, but ok
@@yahm0n Yes, it's basically hollow and amounts to "No". I wrote another comment on this video but since youtube hides and deletes comments with links, I can't link it here. I suppose I can just copy it instead.
"
Color spectrum and the character of the field (flicker/square wave modulated, point source or diffuse, coherence, intensity, etc) are strongly biologically active. The "blue light hazard" usually brings to mind arc welding, bright stage lights, lightning, etc, but modern data shows blue light even at domestic levels (especially at night) destroys the photoreceptors in our eyes and their associated ganglion downstream of oxidative stress (eg retinal turned into ROS). The observation that light and color affect mood and brain activity is ancient, specific findings go back to Ptolemy who found flashing colors from minerals thrown in a fire would alter mood, and Apuleis who found that flickering lights eg from a spinning spoked potter's wheel could trigger seizures and other mental changes. Cold war research (see Controlled Offensive Behavior: USSR) found that red light disturbed alpha rhythm and caused irritability. Green was stablizing and modulatory. Blue had an exhaustive and suppressive effect on the mind, it was draining. Yellow improved work and sense of wellbeing. Plant growth can be modulated by magnetic fields and visible light spectrum. Lastly, being exposed to intense blue light outside the window of time when it would naturally come from the sun, disrupts circadian rhythm, causes neurodegeneration, and promotes cancer.
I strongly recommend wearing yellow shades for night driving. Those bright white LED headlights are not only obnoxious and blind you, they actually cause retinal damage. Flickering LEDs (square wave modulation essentially) cause shockwaves to propagate through the eye. See eg the 1960's FDA symposium on phototherapy for a paper on that, though probably a lot of work has been done since then. LED monitors may also cause retinal damage. LED backlit LCD panels aren't good if they're bright and you're looking at a lot of blue, but overall they're nowhere near as bad. So far only France has issued warnings last I knew, and recognized these risks, even they've been well established in the literature for a long time.
"
@@Acetyl53 I like your long statement much better. On the subject of computer glasses though, the computer can reduce the blue light for you before it even leaves your monitor, so wearing glasses for that purpose is an unnecessary discomfort. The computer can't refocus the image, however, so you actually need glasses for that purpose.
@@yahm0n Yeah, I use f.lux and others, but sometimes just putting on yellow glasses is more effective because there is a general trend of putting blue lights on literally everything. The num caps scroll lock lights on my keyboard, until I taped over them with a few layers of masking tape, were an intense blinding blue. They're still a bit too bright, but better. Speakers, same deal, intense blue ring around the volume knob to show they're on, have to cover it with something. And so on. In urban environments you'll also have LED streetlights and various other sources. So it really is everywhere, not just the screens.
As someone who went down the rabbit hole of lighting quality and light spectrum a few years back, you did an AMAZING job with this video.
Just as a tip, you would get a much more accurate match between light sources by measuring the xy chromaticity coordinates (which your spectrometer does) and inputting the desired value in the light source (if the light source permits). This is for both white & rgb light sources.
I’ll have to try it out
@@ThioJoe can you recommend a spectrometer?
@@Iam2lazy2register A really cheap one would be your phone's camera on raw mode.
You can use a spectrometer to calibrate it one time and then you'll have a LUT.
@@HAWXLEADER i don't think this would help. The camera sensor can only read distinct primary colors. for example if the red and blue pixels are triggert it has no idea if it sees red and blue light at the same time or perhaps a single violet light
@@cookednick I appreciate your answer, however I have to respectfully disagree. I think you are aware that "violet" light is not the same as simply adding "red" and "blue" light in terms of physics. Only our eyes (and cameras) can not tell the difference between those two scenarios. A spectrometer does exactly that: I measures the intensity of rays of each frequency separately of a given electromagnetic spectrum (typically a bit more then the visible light).
Warning
Be careful about these glasses and driving.
I once made the mistake of wearing some very expensive fishing and golfing glasses while driving and nearly rear ended a cop car with the lights going . The glasses completely blocked the red and blue and brake lights.
I'm betting they were polarized glasses, my dad always used them to see fish in the water. Maybe it blocked the flashes from the police car in the same way it does with water reflections?
@@cakobjoker8134 . They were polarised, blue blocker with a dark red brown lens and cost more than Bole glasses.
They were extremely good but unfortunately too good for driving.
Really interesting stuff. I like how you have expanded the scope of your vids. You do a great job of summarizing and presenting sometimes complex (or could be much more complex) subjects.
If your monitor "sears" your eyes...just turn down the brightness. Most people run their monitors far too bright. This is especially important if you work with a white background (like word processing, spreadsheets, email, etc.). It's really simple to do in display settings. I run my Asus laptop at a brightness of 17 on a 0-100 scale and my external monitor at 50. Looks great and plenty of detail. If I'm editing photos I turn it up a bit.
And Windows 11 (10 too) comes with a Night Light feature that turns down the blue cast. You can keep it on 24 hours a day, if you'd like. I don't use that, but it's there if you want it. No need to buy glasses or use a separate app.
My day is made 10X better knowing there is a measurement called foot-candles/second
yoooooo this is spectacular, i already spent a lot of time in your channel, but just now i realized it was all done by you (is pretty common to extract the info and the content you prefer rather than the person itself) so yeah, what a Great video.
Many people in photography use this device. A cheap alternative is to just use a white balance card to balance your colors, but the tlci index rating is very important when buying light bulbs for video or photography.
thanks for taking the time to present this information and shout out to the comments for making me realize my computer has the night light setting!
I'm working with LEDs in my DIY projects right now and your video gives me a lot of keys for working out the questions I had about how I could try to create a good quality of light. I don't know how easy it would be dor a DIYer to find good individual LEDs and tune them, either with physical filters and/or by tuning the intensity of individually different hues, but it is a very fun exploration project I'm in right now and your video falls at the perfect right moment for me. Many thanks!
Great video, the Light quality part is my favorite! Such an important aspect of artificial lighting which so few are aware about, especially now that incandescent bulbs are completely replaced by LED's, many times being cheap, bad quality. I wonder if those really low CRI, high color temp (worst combo IMO) LEDs can actually affect someone's health.
A super Awesome video Thio I love how much knowledge you share with your followers. You are like the chillest tech dude ever!
"I wonder what the weather is like today?"
"Please, allow ME. Close your eyes, though" ~holds spectrometer out the window"
"It's Yellow out there, you're welcome" ~drops device like a mic, but, catches it last second because it cost $1600~
Cool video this Joe. Thanks for the education in lighting!!👍
Man this video was excellent!! From a filmmaker/photographer's perspective.. from a tech enthusiast's perspective.. from a "I used to really like science in school" guy's perspective!! Man great vid, nice job!
I love that you made this video since a couple months ago I notice my gf and roomate’s blue light blocking glasses were crystal clear. They didn’t have any perceivable shift in color, seems very likely if they worked at all there’s no way it’s going to help their circadian ruthenium
Personally, I have a small correction about sodium lamps vs LED lamps.
You'll find in places where weather factors can cause reliability issues, you will still see 100% sodium lamps. LED lamps have trouble coping with brutally cold weather as I recall, while sodium lamps are practically bulletproof.
Interesting, never been personally bothered by blue light, although I do have trouble reading bright blue LED displays.
If your monitor is too bright, turn it down - is my first thought.
I find it rather strange these days, all this talk about blue light being bad, at the same time lots of products being released - like bedside clocks with blue lights. - nuts. (or blue PC case lights)
The lots of talk about it is simply companies taking advantage of people who don't know better, in order to sell them a product they don't need
It's this sort of myth that is used to scare customers into buying products. All research done on blue light is either inconclusive or cannot prove any correlation of "blue" light affecting sleep patterns and/or being bad in general. The presence of artificial lights CAN affect the circadian rhythm, but that's all light in general, independent of the hue. The only good use of the blue filters we have in our devices is that by making screens appear more red we reduce their apparent brightness, which is good if you don't want to be blinded every time you look at your phone in the evening.
That and they don't bother with a proper value of resistor, so they're not just blue lights, they're brighter than the sun itself. I had to tape over the back of my PC's wifi card because it just constantly strobes a blinding blue light for some reason.
Thanks for testing flux with the tool, I was wondering how useful it actually was for late night reading. I'm so happy to see that at the highest settings it does almost completely remove blue light!
Those almost-clear lenses are just like the blue-blocking coating my eye doctor recommended for my new prescription computer glasses. Looks like it should've instead been applied to my driving glasses. "blue-blocking" doesn't necessarily mean all of the color blue that you see, but those shorter blue wavelengths which transfer more energy. Things that react to UV light will also react to the higher blue frequencies as well, and you can use some types of blue LEDs to charge phosphorescent compounds. So if the goal is to block the frequencies which slowly destroy your eyes, those almost-clear glasses look like they'll be very effective.
Gotta love a description that includes the acronym itself. TLMF… Displays the TLMF index.
Wow. So helpful. Nice job manual.
More videos about cool stuff like this please ilu thio joe
I get endlessly irritated by the lights at my place not being accurate. Everything just seems slightly... off.
This video is very good, a complex subject. I used to be in charge of a color matching lab. A customer would want our product to match a color of something of a completely different material. A very difficult job indeed but they want a match. We used a light source that had the capability of showing sunlight, fluorescent light, and incandescent light, all before LED's or other choices. I am now at a church with the goal of saving money on power bills and changing to LED's is a great idea but some folks want the incandescent color back cause something looks different.
I know a few people who don’t like the look of “Daylight” bulbs. I prefer them. IMO, everything looks better with them. I don’t like the look of yellowish bulbs.
A good incandescent alternative are the *filament* LED bulbs that are around 2700-3000k. Just make sure they're high CRI, preferably 90+
I have computer glasses. Same price for one as the double pack you bought, have a slight tint to them. My goodness is the effect noticeable. It doesn't seem to have much of an effect on the colors I see, but the eye strain is just... gone. It improved my sight, too, because of the lack of eye strain.
At work, we're not exactly allowed to be installing our own programs. I use Window's night light feature, but it still doesn't help as much as one might hope, especially because of the fluorescent lights (which may have some effect with UV blocking). At home, I use f.lux and I'm glad to see it getting the praise it deserves.
Could you share which brand you have please?
BTW if you test a pair of clear safety glasses made from polycarbonate, you will find they also block UV and IR
Regular clear eyeglasses (plastic lenses) filter UV too (don't know about IR).
Is it??
Pure red lights are used instead of regular lighting with closely confined chickens. If any birds happens to get a bleeding injury, others tend to peck at them under normal lighting. Chickens won't peck at what they can't see however.
I never could have imagined such a thing lol
there are even chicken glasses with red lens for this exact reason haha I've seen it on a show. just search "storage wars chicken glasses"
@@trei2unu I had seen that in a science book from the 70's Seems the lighting was more workable in the end. I suppose you could GMO a color-blind fowl these days.
It is interesting we call 1-3 k as warm, but it is actually way colder than blue (so called cold light) emitted by object way way hotter than (so called warm) one.
Speaking of light quality, CRI, and TM-30.. maybe do a video where you grab one of each brand/model of light bulb at a local hardware store or various ones off Amazon or whatever, and see which ones perform the best with the better CRI/TM-30 :P
Can be especially useful for those who want good quality lighting on the cheap (who can't afford proper filming lighting yet), or simply those who just want good color accurate room lighting that can also double as filming light.
I'm really curious about why magenta and green...
I work with aircraft avionics and we use those colors a LOT to denote different sources of data. Magenta usually means GPS / FMS (Flight Management System) whereas green indicates a Nav Radio source, and the pilots can flip between these nav sources. There has to be some reason these colors became the standard, right?
my fave is an EM spectrum analyzer with a "matching" greymarket from chindia Jammer, that puts out as much as 1W, love it!
Most of the "yellow" street lights are actually high pressure sodium lights, not low pressure. High pressure widens the spectrum from that monochrome orange to something noticably better.
Low pressure sodium isn't really used anywhere except places that need that precise sliver of spectrum, like near some ground telescopes so they can filter out the light pollution without removing much detail.
Regarding your remark around 11:54 where it seems that the "Amber" lenses are more effective with the screen, you are right about the levels. The lenses are dampening the level based on a percentage, thus the first example it is around 1.3 / 0.45 = 2.89x damping, and in the computer screen it is around 13 / 5 = 2.6. If we could read it out correctly, I would assume that these numbers are the same, so actually it dampens the same.
For these things it is good to plot the values in dB-units (or just logarithmic scaling), as it is better to compare, especially with the true blockers as the curve goes to zero. An even more intuitive way would be to divide the two lines over each other and take the log so you get the optical density (OD), this is common for blocking glasses like for lasers.
Blue-light glasses are silly with computer monitors because each pixel literally has a controllable blue filter in it (or controllable blue level with something like OLED). The test of whether you have blue is how white looks. If it looks orange/reddish, then you're reducing blue. The benefit of blocking glasses is just that you have one place you can reduce blue from *everything* you look at, rather than having to adjust things in the environment (each computing device, light bulbs). And if you're going to get blockers, makes sense to get the extreme ones he shows. Go all the way and make sleep a priority.
A bit of a backstory on Low Pressure Sodium lighting. They were used to reduce light pollution. Astronomers can use a Neodymium Filter to kill that one narrow spike of yellow light and their astronomical photos then are not washed out.
for the monitor, use the night mode feature that windows have. (don't need to have it full strenght) edit: it does the exact same thing as F.lux but it is already on your pc
Or. he could just adjust the monitor's own settings.
Personally, I just prefer going into my monitors settings and turning down the blue LEDs if I need to have less blue light. Actually I'm quite surprised you didn't mention that, despite most if not all monitors having the option.
Then there's also the "night light" mode in windows, that turns down the blue light LEDs for an easy toggle switch.
But but but - that would be too easy to use and for free - can't use that for marketing scam-articles.
yet ANOTHER subject that I did not know that I didn't know .... I appreciate your in depth explanation
14:26 F.lux user here, you might mention its default is to reduce blue only when the sun is down (to assist getting to sleep)
14:00 timestamp.
THATS WHAT I WAS LOOKING FOR MAN THANK U A LOT!
GIB U A WARM LIKE!
I think this was one of your best videos, it was far more informative and I learned things! Thank you.
This is an incident light meter, reflected light will depend on the colour of the object. Photography mostly uses reflected light.
There is a different measurement for printers which rely on reflected colour compared to monitors which radiate light.
I wear corrective glasses all the time, and I've always ordered mine with the coatings for screen protection and glare protection for drivers, since I work on a computer, and I also drive regularly.
However that makes them really expensive. Over 200 euro per lens, and that doesn't include the frame or the work to cut and fit it into the frame.
Damn!!! Price is insane
Quick thought on blue light blocking glasses: People who are using graphics and need to see the colors can take off and put back on the glasses easier than switching the software on or off. Of course, if the need to examine colors is infrequent, it may be better to save money on the glasses and fiddle with the software on those rare occasions.
This is not true, binding a key to toggle the filter on/off is much faster than juggling glasses
@@thatguy7595 It may not be better IN YOUR OPINION, but to say "that is not true" is pedantic.
0:00 - Intro
0:35 - Use Case: Viewing Light Spectrums
3:10 - Various Measurements on Device
3:41 - Use Case: Videography
6:49 - Testing Blue-Blocker Glasses (Explanation)
8:46 - Test: "Clear" Lenses
11:29 - Test: "Amber" Lenses
12:35 - Test: True Blue Blockers
14:33 - Light Quality
16:32 - "Bad Light" Extreme Example
17:57 - How Light Quality is Rated
20:01 - The TM-30 Rating
I worry about computer eye injury from 8 hour days at work. So I really appreciated this video so much.
you can see another good example of "bad light" searching for black fire, it is incredible.
this whole video was GREAT, exactly the kind of thing I wanted to know about, which was delivered to me in an easily digestible format, as I was too busy/lazy to go read about it all myself.
Would those light spikes explain why I had to return those bulbs? I tried using the Hue bulbs and they just hurt my eyes no matter the brightness or colour.
This was much more interesting than I expected! Great video!
from a medical and physical standpoint, you are completely right. A lens cannot block substantial visible blue light without a visible yellow tinge.
This video brought me to an interesting thought experiment. You said that the painting may not look right under the incorrect light but the fascinating thing here is, we don't know what light the artist used when he created the art so the true color to the artist while painting it, could be radically different looking under an ideal light source if he painted it under say a florescent bulb. So we will never get the true painting colors as intended by the artist because the actual colors he saw when painting may be different under a better light source.
"You can visibly see". 'Visibly seeing' is my favourite way of seeing stuff.
20:12 Why 99 colors?
Seams like 100 would be a nice & round number?
Or is it some bullshit like with prices in stores, where eg. $14.99 "looks" cheaper than $15.0 ?
Just a guess, but 99 is easily divisible by 3 so it can be used for rgb, where 100 is not easily divisible by 3 and can mess up rgb colors or make them more challenging to produce with the 3 different values used in rgb. 🤷♂️
Interesting. I recently bought new glasses, on my old ones i had no blue light filter. I work in IT so i sit in front of computer all the time. My new lenses have blue light filter and it definetly helps. They are made by Carl Zeiss block 30% of the blue light and are completely clear - the filter is in the lense itself, no extra layer with blueish/pinkish color. (most common filters block around 15% of blue light and have tint).
There is art light bulbs. Bulbs designed for placement above paintings. As for different light source different effects on the color of different items. Get your girl’s nails done, tell her beauty is pain, and without sacrifice, then there can be no large gain. Now, look at the difference under different light sources. You can see for example one color could be a bright almost neon hot pink, but it will shift it a deep berry almost red. It’s like that for all colors, some more extreme than others.
This was actually quite fascinating.
Thank you so much for this detailed analysis. I’m curious: what would RGB, RGBW, RGBWW lights look like under spectroscopy? Especially when imitating daylight and the warm light of an incandescent bulb? A cursory query didn’t reveal anything of note. Additionally, what light bulbs or sources would most accurately follow the daylight spectrum? This is an incredibly interesting topic for me. For example, what (or how significant is the) impact does the painting of a room have? What about early lighting sources such as fires from firewood or oils or or or? Do CRTs have the same spectroscopy results as an LED monitor?
If anyone has any recommendations on information sources for any of these topics, please let me know. It’s really quite fascinating. Thank you again for the video! 👍🏻👍🏻👍🏻
Try looking up 'barium sulphate latex paint' for an idea of how to make your rooms *MUCH* brighter.
I can't comment for the incandescent under spectroscopy, but a traditional incandescent bulb (and Halogen bulbs, if I'm not mistaken) have a CRI of 1. This is because both sources are black-body radiators, and emit full-spectrum light.
Imitating daylight with these sources is just a matter of applying a gel, which essentially acts as a modifier for the base XY chromacity coordinates.
To emulate daylight, the traditional way to do it is using a type of light called an HMI. These have a CRI of approx 90+, so are generally regarded as having good colour reproduction.
However, it's worth noting that more modern professional-grade (real professional grade, not just whatever the packaging says!) LEDs can achieve a CRI of 95, and have been getting more popular as they have much lower power requirements and weight than a comparable HMI for the same level of output. Another bonus for LEDs, is that for large panels may not need any additional diffusion as their "source" is larger.
Not 100% sure about the fire stuff, but I'd assume they would also have a CRI of 1 as they are again, black-body radiators.
He showed RGB lights at one point in the video; it basically has 3 peaks for R, G, and B. RGBW means that there's an additional broad-spectrum (white) emitter. The exact shape of the spectrum emitted by the white channel depends on how it's generated, but overall you would see R, G, and B peaks overlaid on the W channel's spread-out curve.
Random pedantic point, there is no such thing as an "intrinsic color" of an object. A reference illuminant (e.g. D65) is always needed to derive the final color appearance. So something that "is a red object" is generally assumed to "appear red under a set of illuminants."
The Phillips hue having red and green for yellow is due to it using RGB LEDs. When outeues pick up multiple colors of light from 1 source or reflection, our brains process it as the color between the 2 on the spectrum. Since there's no yellow LED being used, green and red light are used for that effect. You'll see blue and green for cyan for example
Would love to see you using a spectrometer against window tint that claims to block UV. I’m pretty sure that they only block a narrow band but would love to see how they actually perform
The first set of glasses might make more of a difference with older LCD monitors that still have a CCFL backlight instead of an LED one. Those probably do still put out some (ultra)violet light.
Nice video. Taught me a lot about lighting :D
I am very picky when shopping for lights; specifically due to chronic migraines. Now, I am aware not everyone has their migraines triggered by light and mine have been diagnosed as triggered by a combining effect. But, I think light quality as well as temperature is very important for those who may suffer from frequent or non-frequent migraines. Now, here's the kicker - Everyone reacts to light frequency differently when it comes to what temperature may or may not trigger a migraine. As an example I wear sunglasses in almost any building which uses Fluorescent lights. This is due to a few reasons and the biggest being the frequency of said fluorescent light. The 2 most common being 50hz and 60hz. So, these are some things to think about among all the good and useful information received here. Definitely see your doctor though if you suffer from migraines. Cheers! Stay Healthy and Stay Sane!
a trick is to take a prism , or even a 'rainbow sparkle' type decorative/gift wrap paper , up to the light
that way, you will see the colour from the light broken down into its individual components, 'showing its true colours' so to speak
a terrible CFL light would look like discrete blue and yellow segments, an RGB light would look like individual coloured dots ... but an incandescent or high CRI bulb would give a rich and continuous spectrum
The reason some cities use the Yellow Sodium Vapor lamps are to reduce light pollution near an observatory, in which it is easy to filter out a narrow band of light from the surrounding area.
You can find these for about four hundred, a quarter price from apogee instruments, who educates at Utah State, bro... pro grower here, many herb farmers use these with led now as a must have tool.
also migro educates with these tools and has another brand four even cheaper than apogee.. cheers not a shill just a small but once large led farmer
Hm interesting, it wouldn't have the videography features though which is the real benefit for me
There's one more thing about light quality that you didn't mention in the video: PWM/pulsation/whatever you call it. Not every PWM is bad (eg 5kHz is most likely doesn't have any effect on a person).
quite a bit of research you done there! very useful.
Another alternative to blue-blocker computer glasses and/or spectrum settings, when viewing computer monitors: change the display setting from light mode to dark mode. Then, you'll have small amounts of brightness against a dark background.
Very nice video. Explained in simple enough matter, all seams clear. Now I know more.
Are there any "daylight" lamps (or lamp assemblies) that actually do a good job of reproducing a full sunlight spectrum at sea level, including into UV and NIR, and without the spectra dips and spikes, like those at 455 and 485, that are not in real sunlight?
I think there are, at least in the Pro lighting field. Arri for instance. But IIRC these are expensive, power hungry devices that use some form of incandescent light source, which as explained in the video do give a (close to) true black body curve similar to actual sunlight.
Anything based on LEDs basically uses multiple colors balanced to "look like" actual sunlight, but as you can clearly see on his spectrometer, does this by mixing R,G and B to produce white.
20:00 I found this part confusing because it suddenly starts talking about perceptual colors, whereas the rest of the video is about light at different wavelengths, without noting or explaining the distinction. When talking about colors as defined by wavelengths, the spectrum of a light source can't cause the colors to change saturation or shift in hue, as each wavelength is either absorbed or reflected/transmitted (to a first approximation, unless you're pointing the light at a phosphor or something).
You should have tested the blue light reduction feature in windows to see if it gets the same results. Personally I own different blue light reduction glasses with varying intensity, I only use them when my eyes are in pain. It helps a lot.
TL;DR: I'm a nerd when it comes to colorspaces and the math behind color science, and this video is one of the few I've seen which is Actually Good. I have no idea what other content you make, but I'll be watching it even if only to see a 'known good' reference for color reproduction in video, so I've subscribed (and of course I liked the video). I have one tiny complaint, which is not at all your fault.
I've been messing with colorspace conversion code for several years now as a hobby to satisfy some curiosities of mine, and a while back I finally broke down and bought a cheap colorimeter online so I could test my code. I'd like a spectrometer as well, but can't afford one (especially not while unemployed).
Throughout the process, I've seen many UA-cam videos which try to 'explain' color science in various ways, but get it horribly awfully wrong in extremely important ways. So now I happened to see this video, with a thumbnail showing the sort of tool I've been wanting but can't afford, and that made me curious enough to watch...
... And despite the video not being about the device or color science specifically (according to the title, at least), you spend the first seven minutes - and the last eight and a half minutes - talking about it while NOT getting anything wrong! This felt almost (though not quite) like looking into some alternate Universe, and watching myself make a video about some specific thing but quickly devolving into a big long tangent about why color science is so cool. Heck, the only reason why I've NOT made such a video is because I don't know how to constrain the scope very well, and would likely spend two hours rambling about how strange it is that nobody performs L*a*b* conversions using matrices and parametric gamma correction functions despite those being literally all that's needed.
I even learned something NEW from your video, as I hadn't previously heard about TM-30! Looking into it, Wikipedia seems like it Used to have a dedicated article for it, but it's since been merged into an article just called 'Color rendering'. This is awful, but at least in the references there's a link to a long paper that goes through it at a high level.. But unfortunately doesn't give any of the specifics for the math. I'm starting to get the feeling that this is another standard that you need to purchase a copy of to get the actual technical details, which sucks when you want to fiddle with it by writing code and you don't have a way of actually using it in real life. In particular though, TM-30 looks a lot like a more mathematically rigorously engineered version of the 'Farnsworth-Munsell 100 Hue' color blindness test. Color blindness simulation is one of the things I've tinkered with and have an interest in, and I imagine TM-30 can be used to better-standardize the testing conditions, and maybe even formulate a better set of color swatches (or even directly act as the set of color swatches to use).
There is only one thing in your video that was teechnically 'wrong', but is in no way your fault. The 'spectrum' graphs that are colored in to show which parts of the spectrum correspond with which visible colors, including the graphs shown on the screen of your device, are completely bogus and do not at all represent the correct hues whatsoever. For an overview of why, there's a great article on the San Diego State University website that is simply titled 'Rendering Spectra'.
Appreciate all the thoughts and for pointing out the thing about the graph, I'll have to look into that
My amber blue blockers were life savers while teaching online, they also come in different magnifications.
14:10 there is actually built in feature on windows 10 (i don't know there is on windows 11) called night light. it makes your computer monitor bit orange, reducing blue light on your monitor
Me watching this video with Night Mode filters on:
Ah yes, the color reproduction is crucial!
Fun fact, a quick test for dirty LED light is to turn on your phone camera, and hold it up to the light bulb - once it adjusts to the brightness of the light source, your phone display will slightly separate out the differences in R G and B spectrums in a way similar to interlacing. The update rate of the display and shutter catch different pulses of light from each LED. This obviously doesn't happen with blackbody light sources.
I alwa,s thought CRI is suboptimal because it compares to a standard incadescent bulb. Would like a comparison to sunlight on a defined latitude. TM-30 might also alow a recalculation to better match the sunlight at your location.
Good point, but the advantage of comparing against black-body spectra is that it makes the index depend purely on an absolute physical phenomenon which is the same everywhere. The spectrum of sunlight can only be determined empirically, as it gets filtered through the atmosphere, and thus the spectrum as seen from the ground depends on many factors (latitude, angle of sun/time of day, season, altitude, cloud cover, humidity, atmospheric dust concentration and composition, ozone hole, ...). So basing it on sunlight would require arbitrarily picking some "standard" sunlight spectrum.
@@fat_pigeon You are absolutely right, and i don't know if i have a better suggestion, but having incadescent defined as ultimate best just seems wrong. In University we had a wall of many boxes with reference colour sheets, some of the same objects and a different kind of light source in the box. Only few mostly older people picked the incadescent as "best" light. I would mostly pick bulbs marceted as "neutral" around 4000k as prefered source.
Yeah I read a lot of the comments and people are a little weird.. To say at least I think you did a fantastic video a lot of people don't know anything about blue light what it does to your sleep cycles your eyes the nerves in the back of your eyes.I think you did a great job. It's interesting most people don't know anything about it and just giving us an overview is that educational, Most of your videos are by the way, I loved your old Gaming videos there are awesome right up there with the green haired guy without the screaming but I still love watching him Jackaboy. Anyway love your vids keep it up.I like the way you put them at the side at the end of the video. Alot of creators don't. So we can pop into the next video without having to click around. Thanks Joe.!.!
Why would you need to block ALL blue light at night? it's still nice to have things in full color when getting ready to sleep, isn't toning down the blue enough?
I'm not certain but from what I recall, the brain is quite sensitive to the presence of blue light at all for setting circadian rhythms, so if you attenuate blue light only by (say) 50% you wouldn't get that much benefit.
From scamming to informational video,my boi grew up and making change to society
Hi there! My PC glasses are not as yellow as those you show but also not as water clean as that :) what you show. It is a thing in between. I did not test them but I can tell that they are 100% doing what are they supposed to do. Means I am able to sleep better. Great video
Which brand do you use? I can't find them in europe.
Out of curiosity I looked for the CRI rating of the LED bulbs I have here. Interestingly the cheap ones from Aldi claim a rating of 90, while the ones from Philips only have a rating of 80. So it doesn't seem to be related to price that much. Given how small and hidden both ratings were, they are well aware, that most customers don't care about that.
This is really useful if you are an orchid hobbyist growing orchids indoors using artificial lighting
I have a slight prescription and we added a bluelight filter making the glasses a bit yellow (a bit more yellow than the clear ones). In my case, they do take the edge off, and if I'm honest, I don't see any difference between them and my Gunnar Ambers (65%).
If you want a super cheap option for a spectrometer and you know a bit of electronics get yourself an Arduino and a AS7262 spectrometer chip, perfect for testing glasses...cheers.
is that good enough for testing glasses? It has only 6 channels mate
@@arisoda I tried a few tests but I dont have any glasses that block anything specific ! It should give a very course rough test, of course nothing like what Joe's kit can do, but you will see if the blue end is blocked or the red end so I guess it will tell you if a pair of eBay specs are doing what they claim!...cheers.
@@andymouse couldn't you just as easily test that by using a red or blue piece of translucent plastic? So for example, if you want to test glasses for blue-filtering capability, you place something blue translucent behind it and see whether you see any light at all. If you see blue light, then the glasses work. I think this would work because colored plastics will absorb every color except the color of that plastic
@@arisoda yes but my way is more fun ! and far more interesting to get working.
The best suitable title for this video should be "Light science". Thank you for the explanation.