The great EU lightbulb ban, 10 years on

[uppi]

Now you've done it - I'm going to have to blabber on about all the lights I've shined at myself.

Thanks. I appreciate the willingness to sacrifice yourself in the name of science.

Laser spectra of course are far narrower.

Well, sort of. Laser diodes also emit the same broad spectrum like an LED, but om top of that they have the very narrow peak(s) at the lasing wavelength(s). Still you should see mostly the lasing wavelength, since the the difference between lasing light and the background should be more than the sensitivity drop-off of the eyes. Nevertheless, I once used a very narrowband filter (~2nm) to verify it was really the 800nm light I was seeing and not something else.

Hey quick question do humans vary at all in the wavelengths they can see or are we all the same that way??

Anecdotal story: There was once a misaligned laser beam that caused one of the optics to glow in the NIR. I was able to see it in the dark, but my colleague couldn't, because he is (close to) red-blind and probably only has very few cones that are sensitive to NIR light.

I've never heard of anyone being able to see unusually far into the IR, though. Animal vision in general doesn't seem to make much use of the NIR for some reason - many animals see into the UV but the only NIR vision I've ever heard of involved some fish in muddy rivers. Water absorbs significantly in part of the NIR but not all of it; it could just be that it's difficult to get NIR-sensitive variants or that there isn't much survival advantage to it for most animals.

I vote for difficult. I did some mid-IR optics and while you usually can find a solution, this usually involves very strange materials and high-tech coatings. Some lenses came with warnings that the coating contains radioactive Thorium and that you should be very careful in case you break them. Detectors were made from very strange semiconductors and you actually had to cool them to - 70 °C to get rid of the noise. I think it would be very difficult to construct an optical detection system for mid-IR light from organic materials.

 

[Lexicus]

Anecdotal story: There was once a misaligned laser beam that caused one of the optics to glow in the NIR. I was able to see it in the dark, but my colleague couldn't, because he is (close to) red-blind and probably only has very few cones that are sensitive to NIR light.

So, that's interesting. I suppose that means there probably is some slight variation on the margins.

 

[Bootstoots]

Thanks, this is interesting and confirms what I thought about the four-cones thing (they can see more different colors in the spectrum but not an expanded part of the spectrum). IIRC snakes have those face-pit things that can detect IR emissions from nearby animals, but I guess that doesn't really count as "sight" since it isn't their eyes.

Yeah, my understanding is that those pits are very advanced heat detectors. Fundamentally it's just like when you feel warmth from a nearby hot object that you're not quite touching - IR radiation from the object's blackbody spectrum hits your skin and warms it up enough for you to feel it. Pit vipers and the like have a specialized organ that heats up and cools down rapidly and in a directed way, so that they can feel heat from several meters away and pinpoint its location. But it's an evolutionary adaptation of thermal perception, not a "true" eye-like structure in most respects.

Well, sort of. Laser diodes also emit the same broad spectrum like an LED, but om top of that they have the very narrow peak(s) at the lasing wavelength(s). Still you should see mostly the lasing wavelength, since the the difference between lasing light and the background should be more than the sensitivity drop-off of the eyes. Nevertheless, I once used a very narrowband filter (~2nm) to verify it was really the 800nm light I was seeing and not something else.

I see. How much background diode light is there compared to the amount emitted at the lasing wavelength? Are we talking multiple orders of magnitude here?

Anecdotal story: There was once a misaligned laser beam that caused one of the optics to glow in the NIR. I was able to see it in the dark, but my colleague couldn't, because he is (close to) red-blind and probably only has very few cones that are sensitive to NIR light.

So, that's interesting. I suppose that means there probably is some slight variation on the margins.

Yeah, certainly people who have missing or near-missing long-wavelength/red cones are both red-green colorblind and unable to perceive long-wavelength light that others can see as red. There's definitely some amount of variation in the spectral response of even "normal" red cones, although I don't think it's very large.

I vote for difficult. I did some mid-IR optics and while you usually can find a solution, this usually involves very strange materials and high-tech coatings. Some lenses came with warnings that the coating contains radioactive Thorium and that you should be very careful in case you break them. Detectors were made from very strange semiconductors and you actually had to cool them to - 70 °C to get rid of the noise. I think it would be very difficult to construct an optical detection system for mid-IR light from organic materials.

I'm talking more about NIR light, though. The whole range 800-1400 nm should be usable and should work more or less like visible light - water absorbs a bit more past 800 (including a band at 980) but it's not overwhelming. I've found a couple of references to fish that have vision in the 800-900 range because those wavelengths penetrate muddy water better despite the higher water absorbance, but that's about it. So it seems possible, it's just rarely done, and never in the 1000-1400 range. Perhaps there's some problem biological problem in synthesizing good pigments that have enough sensitivity to matter for most organisms, or something like that?

I think noise might become a bit more of a problem too: even at room temperature there are still enough blackbody photons to be visible if we could see above 1000 nm. Did you have problems with noise in NIR wavelengths or is it just mid-IR?

 

[innonimatu]

Probably the coolest variant happens in aphakia, where some people without a lens can see ultraviolet light. The lens adds visual acuity but the cornea already does the majority of the work in focusing light, so for the expense of some blurry vision, people without lenses see deep into the UV down to the corneal absorption cutoff around 305 nm. It does appear bluish-white or violetish-white for them as it does for me when I just stare directly into a UV LED.

Cool it may be for a while but aphakia gets old quickly. I hate precincts with UV lights...

 

[Lexicus]

Yeah, my understanding is that those pits are very advanced heat detectors. Fundamentally it's just like when you feel warmth from a nearby hot object that you're not quite touching - IR radiation from the object's blackbody spectrum hits your skin and warms it up enough for you to feel it. Pit vipers and the like have a specialized organ that heats up and cools down rapidly and in a directed way, so that they can feel heat from several meters away and pinpoint its location. But it's an evolutionary adaptation of thermal perception, not a "true" eye-like structure in most respects.

Indeed - although this brings up the whole "we don't know what it's like to echolocate" conundrum. How "sight-like" really, is that perception that snakes have? We don't really know and there's no way to find out.

 

[Bootstoots]

Cool it may be for a while but aphakia gets old quickly. I hate precincts with UV lights...

What do you see - are UV lights too bright, and are they a blue-violet shifted a bit whitish? Also, do UV lights cause you to see a diffuse blue glow across your whole field of vision? I remember that from messing with UV - apparently it has something to do with fluorescence within the eye.

 

[innonimatu]

More whitish than blue-violet, and kind of too bright!

 

[uppi]

I see. How much background diode light is there compared to the amount emitted at the lasing wavelength? Are we talking multiple orders of magnitude here?

That depends on the diode, wavelength, coating, operating power, temperature, external cavity and all kinds of other stuff. Can be zero orders of magnitude if you have a diode in free-running mode, which isn't supposed to be operated in that mode or if you are operating a diode close to the lasing threshold. Can be around 5 orders of magnitude with an external cavity. For a "typical" free-running diode at rated power, I would guess about two orders of magnitude.

I think noise might become a bit more of a problem too: even at room temperature there are still enough blackbody photons to be visible if we could see above 1000 nm. Did you have problems with noise in NIR wavelengths or is it just mid-IR?

If you don't have problems with noise, you aren't doing science

That said, it kind of depends what you mean with NIR. At 780nm, the noise situation is not perfect, but actually quite good. With reasonable effort you can count single photons. At 1500nm it is significantly worse - detection efficiency goes down, noise goes up and if you want to go single photon counting, you better bring out the liquid nitrogen/helium setup. Still much better than at mid-IR, though.

 

[Manfred Belheim]

I've never heard of anyone being able to see unusually far into the IR, though. Animal vision in general doesn't seem to make much use of the NIR for some reason - many animals see into the UV but the only NIR vision I've ever heard of involved some fish in muddy rivers. Water absorbs significantly in part of the NIR but not all of it; it could just be that it's difficult to get NIR-sensitive variants or that there isn't much survival advantage to it for most animals.

God made it that way so that we could use IR cameras for making videos of nocturnal animal activity without spooking them.

 

[Bootstoots]

More whitish than blue-violet, and kind of too bright!

That's interesting, I'm surprised it's mostly just whitish for you.

Time for more questions if you'll humor me. Does the color of UV vary from person to person with aphakia? Do you ever disagree about the color of something with someone else who has normal vision? What about birds and flowers, in particular - can you see UV-reflecting markings on either of them? When you see a spectrum of colors like a rainbow, does it go red-orange-yellow-green-cyan-blue-violet-[bluish again]-white, with or without the [bluish again]? Is the sky kind of bluish-white, or even white entirely, and never deep blue in the middle of the day?

If you don't have problems with noise, you aren't doing science

That said, it kind of depends what you mean with NIR. At 780nm, the noise situation is not perfect, but actually quite good. With reasonable effort you can count single photons. At 1500nm it is significantly worse - detection efficiency goes down, noise goes up and if you want to go single photon counting, you better bring out the liquid nitrogen/helium setup. Still much better than at mid-IR, though.

Okay then, that's more or less exactly what I thought - noise from blackbody radiation is low at 780nm but increases rapidly past that, so that it is bad enough to mess with your measurements by the time you get out to 1500. If I get a chance, I'll go calculate the wavelength past which noise would be a problem for eyes that otherwise work mostly like human ones.

 

[Valka D'Ur]

The earliest cataract surgery involved simple removal of the lens, which causes acquired aphakia. The most famous case of this was Monet, whose art suddenly shifted bluer after getting this surgery. Nowadays, though, they replace them with UV-blocking artificial lenses, so the effect isn't present. Lots of whiners would complain about macular degeneration and other such things if it weren't for the UV blocking, even though they'd get to push the bounds of perception for quite a while before that happened.

I've never heard of anyone being able to see unusually far into the IR, though. Animal vision in general doesn't seem to make much use of the NIR for some reason - many animals see into the UV but the only NIR vision I've ever heard of involved some fish in muddy rivers. Water absorbs significantly in part of the NIR but not all of it; it could just be that it's difficult to get NIR-sensitive variants or that there isn't much survival advantage to it for most animals.

After my surgery I was given a card that says I have an artificial lens in my right eye. The doctor told me the color splotch on the card is green, but it isn't. It's yellow, and no amount of telling me it's green can make it green.

I guess that's why I'm on the yellow side of the argument over whether Captain Kirk's usual uniform is gold/yellow or green. I see it as gold/yellow.

 

[Bamspeedy]

I'm guessing the ban (in the US) is just on the manufacture of the old bulbs and not the sale of existing supply. My wife just ordered a box of 6-150 watt bulbs last year off the internet (by mistake, she was just looking at brightness and not energy efficiency, and with the charge for returning them we would have only got like $3 back, we just kept them). Have to limit them to light fixtures with only one bulb otherwise we'll blow a fuse.
My parents clung to the old ones for too long just because they look nicer in some light fixtures. Their dining room table light used 6 of those energy suckers.

 

[Kyriakos]

How many eu votes does it take to change a lightbulb?

Spoiler :

ask germany

 

[Kyriakos]

Your former yugoslav lack of humor is telling

 

[civvver]

I'm guessing the ban (in the US) is just on the manufacture of the old bulbs and not the sale of existing supply. My wife just ordered a box of 6-150 watt bulbs last year off the internet (by mistake, she was just looking at brightness and not energy efficiency, and with the charge for returning them we would have only got like $3 back, we just kept them). Have to limit them to light fixtures with only one bulb otherwise we'll blow a fuse.
My parents clung to the old ones for too long just because they look nicer in some light fixtures. Their dining room table light used 6 of those energy suckers.

yes you can still buy them because there are heaps of incandescent bulbs still lying around. Once those run out that's it.

 

[Farm Boy]

I'm guessing the ban (in the US) is just on the manufacture of the old bulbs and not the sale of existing supply. My wife just ordered a box of 6-150 watt bulbs last year off the internet (by mistake, she was just looking at brightness and not energy efficiency, and with the charge for returning them we would have only got like $3 back, we just kept them). Have to limit them to light fixtures with only one bulb otherwise we'll blow a fuse.
My parents clung to the old ones for too long just because they look nicer in some light fixtures. Their dining room table light used 6 of those energy suckers.

You're using 150s inside?

 

[Bamspeedy]

You're using 150s inside?

Just two at the moment (in different lamps).

Normally I would use 75, max of 100 when I had those old bulbs, my parents (if that is what your question was for) used 75 watt as well. When she bought them she didn't know what she was doing (she's not familiar with the whole 'watt' thing as she's not originally from the US) and was just looking at 'lumens' for brightness after I explained what lumens means. She wasn't too happy with herself when I explained how inefficient those old style bulbs are, but she does like the extra brightness. She's always complaining lights aren't bright enough (lamp shades and stuff that blocks some of the light seems inefficient even if it does help the lamp look better).

 

[Valka D'Ur]

I don't use lamp shades. If people don't like the bare bulbs in my lamps, they have my permission to close their eyes (as long as they don't try to go anywhere; I'd hate for the cat to be stepped on just because someone thinks I should use lamp shades).

 

[Farm Boy]

Just two at the moment (in different lamps).

Normally I would use 75, max of 100 when I had those old bulbs, my parents (if that is what your question was for) used 75 watt as well. When she bought them she didn't know what she was doing (she's not familiar with the whole 'watt' thing as she's not originally from the US) and was just looking at 'lumens' for brightness after I explained what lumens means. She wasn't too happy with herself when I explained how inefficient those old style bulbs are, but she does like the extra brightness. She's always complaining lights aren't bright enough (lamp shades and stuff that blocks some of the light seems inefficient even if it does help the lamp look better).

We had the same thing happen, I'm just not brave enough to put them in lamps! They get hot. I wound up with going on 7 years supply of garage/yard lights. Fair number of disagreements over fitting 100+watt bulbs into what are really rather old and cramped light fixtures. I tend to run 60s. Maybe I'm just being unreasonably weird.

 

[Manfred Belheim]

What units do people use wherever your mother is from? ergs per second?