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TrumpterOFyvie t1_j7lomvz wrote

I hate blue LED's. My eyes can't focus on them properly. If you show me a red LED ticker alongside a blue one, the red letters are pin sharp to me and the blue letters are blurred as if I'm not wearing glasses.

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Splice1138 t1_j7m56uj wrote

You might be a more extreme case, but human eyes can't focus on blue light as well, period. I know this first hand (and second, and third) from calibrating three tube RGB projectors back before LCD/DLP.

I also read about it being used in image compression. If you split an image into R, G, and B channels, you can save the B at half resolution and the difference is nearly imperceptible to human eyes, whereas it is easily seen if you do that with R or G.

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Ok-disaster2022 t1_j7mdrk1 wrote

It's frustrating that the headlights from heall are more blue tinted, so no only ate they brighter, but the person using them can't see as well, so they make them even brighter.

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Couldbehuman t1_j7mv5wo wrote

>I also read about it being used in image compression. If you split an image into R, G, and B channels, you can save the B at half resolution and the difference is nearly imperceptible to human eyes, whereas it is easily seen if you do that with R or G.

Never heard of chroma subsampling happening in RGB, generally that's converted to something like YUV which is a Y channel of luminance (about 58% derived from the green channel) and two UV chrominance channels. Both channels of chrominance are then subsampled horizontally by 50%, reducing 1/3 of your original data without even getting to the compression stage. Pretty much all compressed video you ever watch has the chrominance subsampled 50% vertically as well, meaning you've cut the original data size in half.

Point is, not just blue getting subsampled, and since that's what everyone is constantly watching it's pretty safe to say it turned out alright.

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Splice1138 t1_j7n8hfi wrote

The page I read it on might have been simplifying things, not saying that's exactly how it's implemented. I do know if you play around with subsampling RGB chanels via Photoshop, for example, blue is the least noticeable, red somewhat, green very noticeable.

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gk99 t1_j7n356x wrote

There's a movie theater where I live that chose to make its menu all bright blue LEDs and it's almost literally impossible to read.

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WillTFB t1_j7m36pp wrote

Wonder what the science behind this is

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planoavid t1_j7m6nu8 wrote

The lens and cornea of the human eye absorbs shorter wavelengths (blue) better than longer wavelengths (red) so less blue lights reach the retina.

The cones the retina uses to see longer wavelengths are active over a wider array of wavelengths vs the blue cone.

So it is easier for your eye to sense longer wavelengths of light than the blue light.

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ozyx7 t1_j7oeneq wrote

Eyes evolved to be most receptive to things of interest.

Things in nature that are green are very interesting. For example, plants. It's probably important to be able to focus on those, especially if you're arboreal.

Things in nature that are yellow or red are also interesting. For example, fruits, blood, and poisonous things.

Things in nature that are blue are much less common. By far, the most prevalent blue thing we encounter is the sky, and that isn't something that we need to focus on.

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AtraposJM t1_j7xrlta wrote

Not sure this is true but I have a degree in graphic design and I had a teacher tell me that men see yellows and greens a little bit better than women do because when hunting they'd have to see movement in grass etc. Was told to be aware of over correcting for yellows and greens when colour correcting photos and things.

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