Talk:Blacklight

Black light tattoos

Chameleon Tattoo pink

merger

how was black light produced, who produced black light, when was black light made.

Wood's light and Black light seem to be two names to refer to the same thing. Should the article named Wood's light be merged into this one ? 16@r 10:57, 11 March 2006 (UTC)

• yes! --Deglr6328 12:33, 11 March 2006 (UTC)

Yes, seems reasonable.

No. while "Wood's light" is a synonym for "black light", the article Wood's light is about something different—a medical diagnostic technique that uses a UV light to diagnose disease. This subject is distinct, and should definitely not be merged here. I am removing the merge tags. (Feel free to replace them if you still think the articles should be merged after reading this and checking the other article.)--Srleffler 05:28, 29 March 2006 (UTC)

long-wave ultraviolet

--Deglr6328 04:55, 7 September 2006 (UTC)

I was more referring to common use - as in, at a dance club, the tubes would be referred to UV Lights

I don't understand what point you are trying to make. --Deglr6328 03:28, 9 September 2006 (UTC)

I think the point the unsigning person is trying to make is just that the article should mention that, in the U.K., an everyday name is "UV light", rather than "black light". — President Lethe 04:52, 9 September 2006 (UTC)

Yes, that's the point I was trying to make. I've never head anyone in the UK call them black lights, but that may just be the area I live. 81.149.182.210 15:04, 16 September 2006 (UTC)

just put it into the article.--Deglr6328 18:02, 16 September 2006 (UTC)

I've added the note into the article. It could be phrased better, but please don't delete outright, without a discussion here. 81.137.159.61 14:58, 27 December 2006 (UTC) (AKA 81.149.182.210)

Health risks ?

Cancer

Isn't prolonged exposure to UV light dangerous? I heard someone saying that they wanted to purchase a blacklight but the warnings scared them off.

no one knows the extent of such an effect of being exposed to blacklights. but I would doubt it is that serious. after all, if you're not even getting a suntan from your exposure how bad could it be. --Deglr6328 18:04, 16 September 2006 (UTC)

Perhaps a section should be added to discuss this?--Honeymane_{Heghlu meH QaQ jajvam} 01:11, 21 December 2006 (UTC)

If there are citations, go for it but otherwise we'd just be speculating.--Deglr6328 07:14, 21 December 2006 (UTC)

Blindness

I am concerned about the crystalline lens. It opacifies with ultraviolet light, risking cataracts after a life's worth of sunlight. But decorative black lights do not trigger our pupilar reflexes, just as non-UV-proof bad sunglasses. Are black lights dangerous for, say, night-club workers? --84.20.17.84 09:20, 3 July 2007 (UTC)

I believe there may be some danger, and I am sure there has been research done on this. You make a good point about the lack of pupil constriction. Cumulative time spent under the lights without eye protection could yield greater exposure than what one might willingly accept outside or at a tanning salon. UV-blocking contact lenses could be worn and are probably available in a plano prescription (that is, with no prescriptive correction for those who desire only the UV filtering).

As an aside, you might be interested to know a study found unquestionable damage to the lens of the eye from exposure to microwave emissions from cellular phone antennas at very close-proximity to the eye (less than one inch for example). The damage was clearly visible in microsocopy photos of the lens. Some of the damage appeared to be reversible, and some not, if I recall correctly. The study & photos were freely retrievable over the web but I don't have the citation on this computer.

Also see my note on "Skin burns from prolonged exposure" just below.

--Parsiferon (talk) 07:24, 17 February 2008 (UTC)

Skin burns from prolonged exposure

I believe I did get a burn on my exposed skin (especially on sensitive skin such as lips) over the course of 4-5 hours in a large nightclub with intense blacklight throughout. I spent no time in the sun that day but felt discomfort in the club after several hours, and the next morning I clearly was burned somewhat. Perhaps their lights had defective phosphor or were not properly chosen for the application? Perhaps they mixed in some botanical or tanning bulbs by mistake? There was no visible difference among the bulbs, however, as far as I can remember. (Unfortunately we will never know for sure. The building was utterly obliterated by a hurricane.)

Can anyone comment on this please? How about a link to authoritative research on the topic, such as a Medline journal abstract. --Parsiferon (talk) 07:50, 17 February 2008 (UTC)

All the research says UVA light can't damage your skin. Getting burned at a night club with black lights doesn't give us anything to work with, even if it wasn't unpublished original research. As you said, the club could have just had a few black light bulbs burn out, ran out of replacements, and used tanning bulbs instead. So your burn was probably the fault of the irresponsible actions of the club and not the black light.166.122.10.94 (talk) 18:58, 15 December 2008 (UTC)

Last time I checked, tanning bulbs have much more visible light component, and look a lot brighter. I have UV Lighting set up in one of my bedrooms, initially because of a uranium glass collection. Lights designed for raising plants, such as "Grolux", actually have much lower UV levels, and predominantly show red and blue peaks, hence the pink glow. I have some of these set up in my bedroom too. Some people confuse these with tanning tubes. It should be noticed that the slight blurring effect that some people (I include myself) appear to notice when looking directly at a blacklight UV source may be down to the apparent weak fluorescence of the cornea, according to some reading I have done. Finally, the picture in the article is a good idea, but I didn't notice if there was reference to the fact that digital cameras appear to be slightly more sensitive than the human eye at these wavelengths. I have actually tried checking this myself by using a digital camera and also a camcorder in the room with no other lighting than the UV source, and noticed that in the recorded image, or even the viewfinder, the tube appears bright pink, as seen in the article picture, whereas in reality it is much fainter, due to the lack of sensitivity of our eyes at these wavelengths. —Preceding unsigned comment added by 82.6.1.85 (talk) 05:58, 16 October 2009 (UTC)

How used to authenticate banknotes

The article says "Black light testing is commonly used to authenticate antiques and banknotes." My question is how? I have a black light pen for this purpose, but I'm not sure what I'm looking for. Please add your answer to the article. --DBlomgren 03:35, 22 January 2007 (UTC)

I have added a pic as an example. If your bills look different, either your euros are wrong or your lamp is different. My (well, Commons') 5000 Euro cents. --84.20.17.84 09:08, 3 July 2007 (UTC)

Many banknotes have security features printed in ink which is invisible in white light, but brightly fluorescent, often in pale green under UV. In the UK, depending on the issuing bank, these may be bars, numbers, or features in the pictures themselves. The driving licence card also has "invisible" features which appear to be embossed holograms over the card.82.6.1.85 (talk) 01:08, 10 December 2009 (UTC)Lance Tyrell —Preceding unsigned comment added by 82.6.1.85 (talk) 06:01, 16 October 2009 (UTC)

places to buy

yea, i know this is completely not even a major issue, but i've looked on every search engine and cant find anything, but are there such things as 96" blacklights, and if there are, can someone please tell me where i can get some? and if they don't im curious as to why they don't. —The preceding unsigned comment was added by 166.82.242.104 (talk) 01:15, 27 February 2007 (UTC).

Diagram

It would be helpful to annotate the spectral diagram with the visible spectrum colors, and names of non-visible segments. -- Beland 00:33, 11 June 2007 (UTC)

Does semen really fluoresce under a black light?

A google search will turn up many examples of anecdotal evidence that semen will fluoresce under a black light, but I have been unable to find a verifiable source that it does. This article is a scientific study trying 29 different semen samples, and they could not get it to "glow" under any circumstances. The theory is maybe semen does not glow but has been confused with other substances in the past... http://pediatrics.aappublications.org/cgi/content/full/104/6/1342

Similarly for blood. The closest thing I've found that deals with blood and black lights said that blood becomes darker than its background (link). Admittedly, that one's an ad, but a search for "UV and blood" and "blood fluorescence" doesn't provide many results. The former returns references to a spray that makes blood fluoresce (most likely luminol), while the second returns several studies relating to fluorescence of blood with living cells, which wouldn't be the case if blood is spilled (as in a homicide). Can anyone explain? StoicalSoul (talk) 04:04, 18 March 2008 (UTC)

Introduction

A Black light or UV Light is a lamp emitting electromagnetic radiation that is almost exclusively in the soft near ultraviolet range, and emits very little visible light. The black light was invented by William H. Byler, in 1935.[citation needed]

In medicine, forensics, and some other scientific fields, such a light source is referred to as a Wood's lamp.

This introduction is incorrect inasmuch as the page is entitled "Black Light" and is not entitled "Black Light Lamp".

"Black light" is a certain category of wavelengths emitted by various sources including the sun; a category defined only by length.

If the title to the article is to be changed, then the intro should still be edited due to it is misleading; possibly dangerously so given it's many medical applications. The intro defines a "black light lamp" as a singular static object while in true life the wavelengths used for various purposes are bound to be quite specific. i.e. one black light lamp does not necessarily equal another; there are various kinds.

Furthermore, no matter which solution was employed, the reference to "UV Light" needs to be excised or elaborated on due to the only place a black light bulb gets called that is in certain parts of the U.K., like mentioned in an above section of this talk page; which would be fine EXCEPT for the fact that in all scientific literture the term "UV light" refers to a category of waves that can instantly kill or permanently blind a person.

Cakes Downey (talk) 13:30, 14 March 2009 (UTC)

>"Black light" is a certain category of wavelengths emitted by various sources including the sun; a category defined only by length.
Can you provide some sources to verify this statement? I've never seen this term (“black light”) used in any scientific or technical articles to describe a UV light. As far as I can tell, it's just an informal name, and the most prevalent use of it is refering specifically to UV lamps as “black lights”.
>the fact that in all scientific literture the term "UV light" refers to a category of waves that can instantly kill or permanently blind a person.
Is it the fact? Sources, please…
P.S. But I agree that current version of the article is not so good. Older revisions had somewhat better intro. Skarebo (talk) 14:19, 14 March 2009 (UTC)

No, look, the way it works is you only get to change it if you know i am wrong. Unless you can cite to ME the studies that show UV-C does NOT do the things i said, then you must change it back because you are a lesser authority.

Same as u are confessing that you know nothing about why black light waves ARE in the category of black light waves. so, since you do not know, you should not delete someone else's edit.

it is especially inappropriate to leave that info up since you came here and were told it is potentially lethal and you see that it DOES have to do with topics which you know nothing about.

but I'll do this once just to prove it to you. go to the wiki article titled "ultraviolet" and see that blacklight is defined as being waves between one length and another. and then read about food and water sterilization and how it is done with UV-C, a type of ultraviolet light that falls within the category defined as being that which is also called blacklight.

ps- ALL lightwaves are defined solely by length; just like radiowaves and the enire "wave" spectrum.

Cakes Downey (talk) 09:45, 16 March 2009 (UTC)

I have a couple issues/ideas about this article, and this discussion page.

First off, a "black light" is a device which produces UV light within a certain range of wavelengths. Not every UV lamp is a "black light", but the article http://en.wikipedia.org/wiki/Wood%27s_lamp on the Wood's Lamp, states that this device was invented by Robert Wood in 1903. The article on "black lights" contradicts this, with a tagged "citation needed" statement about it being invented decades later by someone else. It is different from the common, popular fluorescent-tube black lights used in entertainment fields, in that it uses a special lens - a "Wood's Lens" referenced on the Wood's Lamp article and also having it's own entry here) placed in front of an incandescent light source, which lens filters out most of the visible light and "hard" UV and passes mostly "soft" UV light (in the ranges that are not known to be dangerous, at least at the intensity these devices produce) but the Wood's lamp, the fluorescent entertainment-oriented black lights, the newish UV LEDs, and other similar devices (such as mercury-vapor lamps with filter-lenses resembling, if not actually _being_ Wood's Glass, of which I own several) all produce "soft" UV which can be described as "black light". This can, should, and must be distinguished from "hard" UV light, such as produces sunburn and skin cancer, eye damage, etc. There are very common "hard" UV lamps in use in various industries which produce diffrerent wavelengths than "black lights" - tanning beds are one example, as are "germicidal lamps" used in agricultaral and other industries because their "hard" UV light kills dangerous microorganisms. However, these "non-black light" "hard" UV sources produce dangerous wavelengths of UV that can cause blindness, skin damage, etc if a human or animal is exposed to them, much like the "hard" portion of the Sun's UV spectrum, only stronger. These are substantially different from the Wood's Lamp and the "entertainment" types, which are, in turn, very similar to each other. My mercury-vapor "Wood's Glass"-filtered blacklights illuminate tinea fungus just like a medical Wood's Lamp, for instance, although my LED "blacklights" do not, due to producing a different wavelength of UV light - but neither the Wood's Lamp, the "entertainment black light", nor the UV LEDs produce harmful wavelengths, at least as far as well-documented, peer-reviewed medical research and literature show.

I've played with blacklights for decades, and been an amateur physicist (with some interests being optics, vision, and effects of various wavelengths of EM radiation on the human body) since childhood, and have recently brushed up and studied a lot after having a tenacious and obnoxious household outbreak of tinea (ringworm, etc) and I also had the misfortune of getting hold of a germicidal "hard" UV lamp as a kid and trying to play with it as a "black light" (it sorta worked, and then my eyes sealed themselves shut with "eye-boogers" for about 12 hours, and now I don't see short-wavelength (blue, violet, etc) visible colors clearly - the reds and yellows and greens focus but the blues and visible violets diffract and create star-patterns in my eyes. I'm just glad I wasn't blinded permanently, and at 40-low-something years of age, my vision is still good enough to function reasonably with no correction, though after a corneal injury and family history of cataract development, I expect worse trouble in the coming decade. And I got a prescription for glasses/contacts but it's been low-priority since I can still see well enough to drive, operate a computer with a a high-resolution screen, etc. But after having 20/18 vision until age 30 or so, I do get frustrated sometimes.)

As an informational aside, common "halogen" household reading and work lamps come with a glass filter designed to remove harmful "hard" UV, and warnings that they must not be used without said filter. Don't ever use a halogen reading or work lamp without its glass filter in place, or you are likely to injure your vision and/or worse.

I don't know how (or have time) to figure out how to integrate/disambiguate/resolve all of this stuff here, but I wanted to put this information out for consideration by whomever does so. I've edited Wikipedia entries for accuracy before, but I'm stretched too thinly over too many things now (and suffer severe ADHD) to give it proper focus and attention and resulting unambiguous accuracy. But I wanted to present this information here in discussion so that anyone working on clarification/combination/disambiguation can add it to their study material and research in improving these articles. —Preceding unsigned comment added by 75.71.80.12 (talk) 13:56, 13 July 2009 (UTC)

Invisible

A black light can make images "glow", but can it make invisible images visible (can I draw a picture on my wall that you can only see when I turn on a black light), or can it make, as questioned above, invisible stains visible? - 121.208.89.240 (talk) 08:39, 19 July 2009 (UTC)