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Technology

Ultraviolet Digital Cameras 40

Posted by CmdrTaco from the do-you-see-what-I-see dept.
An anonymous reader wrote in to tell us that "Scientists at North Carolina State University's Solid State Physics Laboratory say they have built a camera that can take pictures of anything that emits ultraviolet light." And we'd like to announce an update to the RobCam: I think Hemos and I will be wearing a lot more white.
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Ultraviolet Digital Cameras More

Ultraviolet Digital Cameras

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  • Oulaw them! (Score:1)

    by Anonymous Coward
    We must protect our children!!!!!! Oh, wait.....I thought you said UltraVIOLENT digital cameras.....
  • No, near UV light has been imaged since the early days of film photography. But I believe this is a significant advance in the direct electronic detection of UV light. As someone else said, UV light is usually detected electronically by fluorescence: take one UV photon, and use an absorptive chemical film to convert that into two visible light photons. (That's what Tide laundry soap does to make "whites whiter!" etc.)

    The energies discussed are definitely "near-UV". That is, wavelengths of 200-400 nanometers (the human eye can see from about 400 (blue) to 700 (red) nm. Far UV (about 100 nm) and Extreme UV (less than 100 nm) are not included in this technology. X-rays (1 nm and shorter) are definitely out (but actually, CCDs are used on the new Chandra X-Ray satellite [nasa.gov] in funky ways). Down to about 100 nm (or maybe lower?) you can use conventional lenses, but they must be made out of magnesium-fluoride (MgF) instead of glass. It's not really until X-rays that you have to use bizarre techniques to focus light (like nested grazing-incidence foil mirrors).

    This is new technology to do a better job of old science (at least from the astronomical point of view).
  • Yep, you're certainly right that snapping pictures in your backyard at night with a digital uv camera is unlikely to really push the envelope of cosmology. OTOH, its not easy to get funding for pure research in this day and age, so it never hurts to hype up spin-off technologies to the PHP's (pointy-haired politicians).


    It would be very interesting if they can get aluminum gallium nitride diodes to emit coherent uv radiation, talk about data storage on CD's... Anyone know of other UV laser technologies? I know that there hasn't been any success in creating an X-ray laser yet; X-ray emissions, yes, coherent, no (last I heard).

  • pah, thats nothing (Score:3)

    by Yarn ( 75 ) on Sunday September 19, 1999 @10:35PM (#1672849) Homepage
    Where I work we have digital cameras* that take pictures in 3D and work with gamma rays. And a camera that constructs 3d images from radiowaves in a magnetic field.

    PET and MRI (aka NMR) are old technology tho, PET's resolution being limited to ~8mm iirc, due to the fact that a positron has to drift a certain distance before annihilating (Statistically speaking). MRI's drawbacks are that you cant have any metal in the subject.

    Oh, and they're both expensive

    (* If you define a digital camera as something that creates images from life)
  • yes, but have you seen a camera that can see through bikinis?

  • Kiddie-science article (Score:3)

    by PigleT ( 28894 ) on Sunday September 19, 1999 @10:49PM (#1672851) Homepage
    "All stars emit ultraviolet light, so compact digital cameras sensitive to that wavelength could open a new window on the universe."

    Erm, yeah, like I didn't know that?

    More to the point, what is a digital camera, at eg 1152x864 resolution, going to see that the big boys can't now?

    I think the whole thing is just a tad simplistic but ludicrously optimistic, typical journalist-meets-brains syndrome...
  • So basically you're looking for hard facts with no background and no speculation.
    I thought that the article was interesting; I didn't learn a great deal from it, but neither was I gnashing my teeth at the author's belabouring such obvious facts as 'stars emit ultraviolet light'.
    As for its 'target audience': The Nando Times contains sections on sports, politics, entertainment and business (amongst others). I'm willing to wager that a significant number of the people aren't aware of the properties of UV light.
    Just because it's in a 'tech' section doesn't mean its target audience is geeks and scientists.
  • wasn't that the sony camera that was released (or escaped) last year?
  • ...they're also sensitive to IR - try aiming your TV remote at one. Lots of fun can be had confusing people by making displays out of IR LEDs so that they can only be seen on a monitor! (incidently, anyone ever tried saturating their car/bike number plate with IR to defeat speed cameras? ;)

    [Happosai]
  • Sort of. I don't mind the background (limited) and some speculation (very limited).
    What I really objected to was the feeling that alternate sentences were interesting or stating the blindingly (pathetic pun intended) obvious. Hence the comment about target audience - it seems to be trying to appeal to nobody of all areas, rather than anybody in one field.

    But that's just my paranoid impression :)
  • That's why they're usually said to cut the "haze" on overcast and hazy days -- the lower light levels makes it more noticable. Its also a matter of what colors the light registers as on the film as compared to the visible-light color of the same object. Sometimes it'll just minutely shift the color and fuzz the outlines. How stopped down the lens is, what kind of lens it is and factors like that also affect it. You'll almost never notice it on a handheld shot. But if you shoot a scene on a more overcast day on a tripod with and without the filter, depending on the camera it can be very noticable.

    The more glass there is in the lens (the more elements) you also strip out more and more UV.

    Do some searching on the net, I've seen a half-dozen sites with ultraviolet galleries.
  • Most standard chemical-based film stock is also ultraviolet sensitive. That's why even novice photographers know to put a UV filter on the lens, because lenses focus the ultraviolet at a different point than the other colors (and ditto with infared, although non-infared film is rarely very sensitive to infared, whereas most film is fairly sensitive to ultraviolet), and you get a hazy look to the film -- the haze is just a blurry exposure of the scene in ultraviolet.

    For any amateur shutterbugs out there, if you can find a quartz lens that fits on your camera (they're very hard to find and VERY expensive unless you get really lucky), you can get filters to put on the lens that will cut out all the visible light, letting the ultraviolet through, and you can actually shoot very interesting photos in UV using standard film. Exposure times are longer, and you've got to guess on the exposure because meters won't read the light levels, however.
  • Comment removed based on user account deletion
  • If you're looking for imaging devices that can look through clothes, you need to look at microwave cameras.
    I don't know of any that are commercially available (or portable) and they're not exactly priced for the home market either.
  • I can do that with my x-ray specs if I squint REAL HARD...

    The device itself has a LONG way to go before being useful for a lot of applications that need more than a simple 'detection' of UV. The article says that the chip is an array of 1024 detectors (ie: a 32x32 array) which is hardly enough for any serious visualization usage. It is a good first step on the way to 'consumer grade' UV detectors which are good enough to be considered cameras.

    Right now, it's just a small slab of detectors a few dozen on a side. While even at that size it could be very useful in certain applications (I've got my doubts about the weld examination if one only has a 32x32 pixel window to view with!) it won't be really widespread-useable until there's at least a 256x256 (or maybe 300x200, given digital's trend towards 3x2 ratios) pixel device. Then I expect you'll have spy shops all across the net selling UV-enhanced spy cameras. ;)

    --
    rickf@transpect.SPAM-B-GONE.net (remove the SPAM-B-GONE bit)

  • I can see it now. Hidden web cams at popular make out spots with ultraviolet flashes. I would like to see one of these on a hand-cam, or in an infered version.
  • Actually, the big deal here is the nature of the sensor. It's a solid-state CMOS camera, an array of UV sensitive photodiodes attached to a CMOS readout. Single chip camera.
  • What *I* found interesting in this article was the mention that the same types of diodes could be used to generate many different wavelengths of light very efficiently, and that they were being used for such purposes in Japan as billboards already.

    Does anybody have any guesses/info about how what kind of resolution (both spatial & for color) you can generate using these types of diodes, and for how much?
  • I thought that one was infra-red.

  • But can it see through clothes? (Score:1)

    by Anonymous Coward
    Like the sony nightvision cams w/ filters???

    Otherwise, geeze, what's the point.

    :-)
  • So can a $30 refurb Connectix B/W Quickcam, if you
    do a little surgery on it.
  • As far as my experience goes, photodiodes and photodiode arrays have been used extensively for spectroscopic applicaitions such as UV absorption, fluorescence, etc., for quite some time. If you have around $20k, you can call HP and get a nice UV-VIS adsorption spectormeter with photodiode array detector for your very own :)

    There may indeed be a breakthrough in design which may reduce costs, increase efficiency, wavelength rage, etc., or possibly a novel use for UV detection/sensing. But this article does not point anything like that out. This defiantely does not seem like a fundamental scientific breakthrough.

  • Currently the majority of visible and near-visible astronomy is done with CCD cameras (same technology as typical digital cameras and camcorders) which have peak sensitivity in the red or even IR. This makes it rather hard to study blue stars. The further blue you go, the less transmissive the atmosphere is and the brighter scattered moonlight appears (y'know, the sky is blue and all). So, having a camera that has poor sensitivity in the blue is doubly bad.

    On a less technological and more historical note, prior to the 1980s (or so), photographic film was the dominant technology for astronomical imaging. Since most film has higher sensitivity in the *blue*, there was a lot of astronomy done at that end of the spectrum. Using CCDs today, it can be hard to compare to the blue work of the past. With new cameras specializing on blue and UV light, better comparisons with previous work can be made.

    So it's quite wrong to say that new UV cameras will open up a new window in astronomy. In fact they will reopen an old window!
  • There's already consumer-grade cameras that have sensitivity in the IR spectrum for night vision. Check out any online 'spy store' and you'll see 'em all over. They cost a few bucks, but if you want surveilance that's able to see in the dark without drawing undue attention with coherent light floodlights, they're the way to go.

    Even the CCD on my Sony handicam can see IR... just switch on the 'night shot' mode (which basically introduces a IR filter into the optics and kicks on a small IR spotlight on the front, IIRC) and away I go. It'd be nice to have similar sensitivity in the UV spectrum, for "cool toy" purposes if nothing else. ;)

    Thing is, UV light has a tendancy to make things floresce (glow), so useful applications for clandestine surveilance would probably be limited to available-light... ie: have no real advantage whatsoever.

    (I'm not going mention that someone setting up spycams at 'make-out spots' really needs to find a new hobby or three...)

    --
    rickf@transpect.SPAM-B-GONE.net (remove the SPAM-B-GONE bit)

  • http://www.discovery.com/cams/sun/sun.ht ml [discovery.com]
    Although they admit that it's actually four separate cameras, each just capturing one wavelength of UV light - so presumably using different technology?

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