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Wavy Lenses Extend Depth of Field in Digital Imaging 359

Posted by CmdrTaco
from the optimize-this dept.
genegeek writes "On Feb 25 CDM Optics was awarded a patent for a new digital imaging system utilizing "Wavefront Coding" that produces images with 10-fold the depth of field of conventional lenses. The image itself is blurred until processed. Image examples are here."
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Wavy Lenses Extend Depth of Field in Digital Imaging

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  • So (Score:4, Insightful)

    by Ravenscall (12240) on Tuesday March 18, 2003 @01:41PM (#5537684)
    Basically what this is saying is that if I go out and get a new whiz-bang camera with this funky new lens, I will be able to take a picture almost as good as the pictures I take with my 30 year old Cannon AE-1, and not have the leeway of doing photo processing tricks in the darkroom.

    Personally, I will stick to analog photography.
    • Re:So (Score:3, Interesting)

      by Deth_Master (598324)
      So, just take a trip to the next space telescope we put out into space, once every couple of months to get the film from it.
      I mean this has it's advantages, perhaps not to the average joe. I like analog photography too, but digital will work much better in getting images from space probes, satellites, and other far off devices, hell, even spy-planes, to another location really quickly.
    • Re:So (Score:5, Interesting)

      by egomaniac (105476) on Tuesday March 18, 2003 @01:47PM (#5537740) Homepage
      Basically what this is saying is that if I go out and get a new whiz-bang camera with this funky new lens, I will be able to take a picture almost as good as the pictures I take with my 30 year old Cannon AE-1, and not have the leeway of doing photo processing tricks in the darkroom.

      You stick to your film. I'll stack my Nikon D1X against your 30-year-old camera any day of the week, personally. And that's not even top of the line anymore -- Canon has a new 11MP camera that puts any 35mm camera to shame.

      Just because $300 consumer digicams are crap doesn't mean that digital hasn't already surpassed film. It's just a matter of making it affordable now.
      • Re:So (Score:3, Informative)

        by burninginside (631942)
        it takes about 25+ megapixels to simulate 35mm film or about 100 megapixels to simulate medium format film, or 500 megapixels to simulate 4x5" film. For the internet even 3 MP is fine, but it becomes obvious in a gallery size print
        • by JeremyR (6924) on Tuesday March 18, 2003 @02:22PM (#5538026) Homepage
          There are at least two experienced photographers (Rob Galbraith and Michael Reichmann) who feel that the 11-megapixel Canon EOS-1Ds delivers images with detail exceeding that of 35mm and approaching (in some cases besting) medium format film. They've published some very interesting comparisons:

          http://www.robgalbraith.com/bins/content_page.as p? cid=7-4833-4853

          http://www.luminous-landscape.com/reviews/camera s/ 1ds/1ds-field.shtml

          This may just change someone's opinon on how digital compares to film. I know it made me rethink the "conventional wisdom" that many more pixels are needed to reproduce film detail.

          Cheers,
          Jeremy
        • Re:So (Score:3, Informative)

          by blaine (16929)
          This is false due to missing an inherent weakness in film: grain.

          It's been shown in side by side tests of large prints that 10-11Mp is far superior to 35mm film. Despite 35mm being technically able to hold more information than that, the grain of the film causes the images to come out looking worse.
          • Re:So (Score:5, Informative)

            by plover (150551) on Tuesday March 18, 2003 @06:10PM (#5539877) Homepage Journal
            Except that weakness turns out to be a strength when dealing with aliasing. The random orientation of the individual grains avoids aliasing issues. Even at a resolution exceeding that of the film grain, a grid of parallel lines (especially parallel or concentric curves) can produce a noticable moire effect. Also, I've found that angled black and white lines can have noticable color artifacts (although I understand there's a new CCD technology that's supposed to overcome this problem.) The randomness of the grain also seems to provide a "softening" effect that I personally find more pleasing than the regularity of a matrix of pixels.

            Don't get me wrong: I *love* my Canon PowerShot G2 (4MP). I've been extremely pleased with the results in a 4x6 format. I've blown up some as large as 8x10 (had them professionally printed and developed) and find that the quality is almost as good as prints made from 100 ISO 35mm film. Having "during the shot" color balancing also makes it much easier to get useable prints without serious headaches. And it's certainly more conveinent to me to have the images digitally available, too.

            I also find that without my old-school mental block of "don't waste film" is gone, and that I now take many more shots than I used to. It leads to a bigger choice of shots to choose from, so I now get better final prints. Yes, I know I wasn't supposed to worry about "wasting film" before, but those old habits are very hard to break.

        • Re:So (Score:3, Informative)

          by jcr (53032)
          it takes about 25+ megapixels to simulate 35mm film

          No, film grain tops out at around 4K lines of resolution across a 35mm frame. That's more like 16 million pixels.

          Where film is tough to beat is in its dynamic range, not its spatial resolution.

          -jcr
      • Thats just it though, you can go out and drop a grand on a digicam just to take pictures of the same quality as a hand-me-down camera from my dad.

        Granted, as others pointed out earlier in this thread, digital is more convenient, Analog still has better quality, and is unsurpassed for artistic purpuses.
        • Re:So (Score:5, Insightful)

          by blaine (16929) on Tuesday March 18, 2003 @02:21PM (#5538014)
          Yeah, and you don't have to buy film for a digital camera.

          Don't think this is a big deal? I'm into amateur photography, and I have a camera that I only bought 9 months ago that I've taken 1500 shots with. Have I kept them all? No. Have I printed them all? No.

          And that's the point, for me. I paid $1k for a camera, and now I can take as many pictures as I'd like, without having to pay for it every damn time. The pictures that I do want printed, I can get done for very reasonable prices at places like Shutterfly. And the ones that turn out bad, or I just don't feel like printing, cost me exactly $0.

          Do some math. How much would I have spent on film and processing for a traditional 35mm camera in the last 9 months, had I gone that route instead of the digital? By my reckoning, it'd be at least $500, if not more, depending on the quality of the film I purchased. Within another year or so, the camera will have paid for itself, if only in reduced cost per image.

          And as for artistic purposes ... uhh ... what? A lot of professionals and artists have begun switching to digital. There's nothing about digital that makes it any less artistic. In fact, if nothing else, it gives the artist more freedom, in that they can more easily review their work, and learn from their mistakes. The turnaround time is far shorter (ie. instantaneous), and that means that they can take more shots, and more quickly tell if they're getting the effect they desire.
      • Re:So (Score:4, Insightful)

        by mrm677 (456727) on Tuesday March 18, 2003 @02:03PM (#5537878)
        Ok, I'll load my 30-year old Canon with some Kodak Technical Pan film. Lets make 16x20" enlargements and see how we compare, huh?

        Or, lets take wide-angle pictures. With the cropping factor on your Nikon D1X, how can you be any wider than say 32mm (35mm equivalent).

        Digital is great, but in some cases, 35mm cameras are still superior. Especially low-light and wide-angle photography.
        • Re:So (Score:4, Informative)

          by egomaniac (105476) on Tuesday March 18, 2003 @02:23PM (#5538032) Homepage
          Ok, I'll load my 30-year old Canon with some Kodak Technical Pan film. Lets make 16x20" enlargements and see how we compare, huh?

          I've made 20"x30"s from this camera with no complaints. They weren't razor-sharp, but then again neither are 35mm prints at that size. Yours will be a bit sharper, but mine will have no grain and better color. Which one is better is a matter of opinion. And against Canon's 11MP, you wouldn't have a prayer.

          Or, lets take wide-angle pictures. With the cropping factor on your Nikon D1X, how can you be any wider than say 32mm (35mm equivalent).

          I have a 17mm lens (17-35mm F/2.8 AFS), which is 25mm equivalent on the D1X. If I went down to Nikon's rectlinear 14mm, I'd get 21mm equivalent. That's certainly wide enough for almost any application.
          • [A digital print] will have no grain and better color.

            Digital will never match the colour of slide film. It can't, by definition. It may be more vivid, due to some post-processing tricks, but it will never be as real or as authentic. Slide film captures the colour exactly as it was, whereas digital rounds it to the nearest bit. Slide film colour is as faithful and rich as the real thing.

            • Actually, that's not true. Film captures color as realistically as the photochemicals can react to the incoming photons.
            • by egomaniac (105476) on Tuesday March 18, 2003 @03:59PM (#5538802) Homepage
              Slide film captures the colour exactly as it was, whereas digital rounds it to the nearest bit.

              This is what we refer to as "argument by bizarre definition".

              Slide film captures color via photochemicals that change in response to light. Digital cameras capture color via sensors that signal in response to light. Saying that one is better "by definition" is patently absurd.

              If slide film is inherently perfect, why are there so many different slide films with different color responses? If slide film captures color "exactly as it was", why is Fuji Velvia widely known for producing great landscape shots but murdering skin-tones? Slide film has all the same color concerns that any other capture method has -- good red response but poor greens, or great blues but muddy purples, for instance. Nothing is perfect, especially when the only real way to judge them is using the also-imperfect human eye.

              I'm not basing my "better color" assertion on a bizarre definition of the abstract ideal. It's just my opinion, but I hold that my professional digital SLR, with little or no post-processing, produces better color than anything the film world has to offer. "Good color" is a subjective thing, and while you may disagree with me about that (cite examples please!), I stand by my statement.
            • It may be more vivid, due to some post-processing tricks, but it will never be as real or as authentic. Slide film captures the colour exactly as it was, whereas digital rounds it to the nearest bit. Slide film colour is as faithful and rich as the real thing.

              This sounds just like the whole 'Analog sound is warmer' argument I hear from some guy that just spent $15k on a stereo.

            • by Andy Dodd (701) <atd7@corne[ ]edu ['ll.' in gap]> on Tuesday March 18, 2003 @05:00PM (#5539328) Homepage
              If anything, as other people posted, digital is closer to the "real thing".

              One person mentioned that Fuji Velvia is great for landscapes but murders skin tones. This is because the sensitivity curve of a digital can be easily optimized, while it's very difficult to tweak the sensitivity and linearity of films based on chemical reactions.

              As to rounding to the nearest bit - There's a lower limit in both electronic and film recording of the precision that a light level can be recorded which is distinguishable from noise. This is called the "noise floor" - Use enough bits, and then all the bit roundoffs will be well below the noise floor of even film media. (Which does indeed have a noise floor, just as digitals do. The nice thing about digitals is that with improved electronics and sensors, the noise floor of the sensor is dropping while film is staying the same. One of the things "pro" digitals are known for is having far less noise than lower-end digitals, and those improvements are constantly moving down to the consumer level.)

              And for those that WANT the nonlinearities/quirks of film - All a camera manufacturer has to do is model the nonlinearities of major film types and then they can easily be emulated, just like guitar amps that use modeling techniques to emulate older units.
      • You try blowing up your 11MP image to 30"x40". I can do that just fine with my Kodachrome 64 on my Nikon FG camera.
        • Re:Gimme a break (Score:4, Informative)

          by egomaniac (105476) on Tuesday March 18, 2003 @02:15PM (#5537972) Homepage
          I don't get the sense that you've ever used a good digital camera.

          I've blown 6MP images up to 20"x30". They look great. Good enough that people gush about how great they look when they buy them from us, at least. While I don't have access to an 11MP camera, I can't imagine that 30"x40" would be too much of a stretch.

          Keep in mind that I'm talking about images from a $5000 camera, not a piece-o'-crap point-and-shoot.
          • No, I haven't personally, but I've seen what they can do and I haven't been impressed. There's a certain quality and tonality that you simply cannot get from digital at present. Ideally, the best way to view the slides is not printed, but projected. Once projected, there's a vividness unlike anything digital can produce (at the moment for any kind of "reasonable" price).
            • Projecting my digital photos using a video projector gives them a vividness unlike anything I've ever seen in a hard copy. There's an "inner glow" to a projected image that paper just can't match. ;-)
      • by caveat (26803) on Tuesday March 18, 2003 @02:08PM (#5537909)
        Just because the base image quality may not be better (for 8x10 and larger from a 35mm sized camera, digital is so much better, but I like analog for 3X5 snapshots) doesn't mean the tricks and effects are neccessarily better.

        Photoshop is great software, but no matter how much I try, basic manipulation (on b&w images particularly), especially brightness/contrast adjustment and dodging/burning, always gives me much better results under an enlarger. Same for exposure effects; Photoshop's solarize filter is good, but there's just some intangible warmth and...analog-ness to a well-solarized paper print. Maybe it's just the random scatter and size of the grain of film against the gridded regularity of the digital images, or the slight variation in quality across the print (not imperfect, but not...digitally homogenous), but for purely aesthetic ends, I have to go with film and paper.
        • The real problem there is dynamic range. Photoshop still works in 8 bits per channel, which is clearly not enough for any sort of exposure / brightness / contrast control. You need at least 16 bits per channel, preferably 32 (in floating-point format). Photoshop can load 16-bpc images but 99% of its tools are disabled until you convert the image down to 8-bpc. In other words: the 16-bpc mode is there just for marketing.

          There are some interesting HDR (high dynamic range) projects, such as HDRShop [debevec.org], and these
        • HDRI vs RGB (Score:3, Informative)

          by NickFusion (456530)
          That's because Photoshop & most digital cameras only use RGB colorspace (24 bits) which is a crappy color space, and one that we're currently stuck with because of our display devices.

          High Dynamic Range Images use a higher bit depth (12 bits per chanel?). Many of the Nikon cameras can save out these 12 bit/channel images, which, with the proper manipulation software (HDRShop, others) can be used for much finer and subtler manipulation.

          So, (math skills permiting), I make that out as 4096 levels per ch
      • Re:So (Score:3, Insightful)

        by esper_child (515754)
        Digital hasn't surpassed film, and never will. They are two different mediums. And yes, I have done that challange before, my 30 year old 135 camera put the digital in its place. The only digital I have seen that could match my camera for detail was a digital backing someone made for the various medium format cameras out there. 11 MP is not something that I would worry about putting my 135 film to shame. It takes atleast 16MP to match the detail of Velvia (yes it does matter what film you compare to
        • Re:So (Score:3, Interesting)

          by deathcow (455995)
          I'm sorry to tell you, but you are just plain wrong. Does your camera exceed the laws of physics? Can your lenses somehow focus a point-like source of light to an abnormally small airy disc? The answer is NO.

          Realize that the Canon 1Ds has pixels that are SMALLER than the airy disc size at almost all f/stops. You simply cannot achieve better resolution with the lenses available.

          Believe what you want about your 135 film, but it takes APERTURE to shrink the airy disc and improve the true image resolution. As
      • Depends on the film you're talking about. Low-sensitivity 35 mm film and most good 60/70 mm film is still better than normal (ie, "instant-shot") high-end digital cameras. Digital will probably catch up with those in the next 12-18 months, though. And IMO the extra quality that you can get out of film under the ideal conditions is not worth the extra work & time necessary to get it into an image editing program.

        Now, show me a digital camera that can do 4096x3192 / 10 bpc / 125 fps and I will be impress
      • Just because $300 consumer digicams are crap doesn't mean that digital hasn't already surpassed film.

        You're right. There are several other, perfectly good reasons why digital has not yet surpassed film. Time-lapse, low-light, and infra-red exposures come to mind.

        • Um, you just named a number of areas where electronic imaging is king.

          Low-light: CCDs have been used heavily by astronomers for quite a while due to their exceptional low-light performance. (Esp. when actively cooled.)

          IR: For near-IR, current image sensors are excellent. In fact, digital camera manufacturers must use an IR-blocking filter in order to prevent IR sensitivity from being a major problem. Remove this filter and you have an excellent IR camera. Sony image sensors are more IR-sensitive th
      • Re:So (Score:4, Insightful)

        by Cerebus (10185) on Tuesday March 18, 2003 @03:27PM (#5538569) Homepage
        My ancient Pentax K-1000 only uses batteries for its internal light meter. In fact, my K doesn't have batteries in it right now; I use a handheld self-powered meter to take a reading, and my own experience to judge exposure.

        I can shoot in in extreme cold and extreme heat. What's the temp rating on your batteries?

        I can choose the light sensitivity I need for my shooting conditions, bound only by the speed of the film available to me. How fast, in ISO numbers, is your CCD? I can get 3200, 6400 or higher. And for special effects I can go infrared.

        My permanent storage is both cheaper and more permanent than yours over the long term.

        Finally, a lot of Pulitzer shots are extra shots that were initially unpublished. Digital storage invites a photographer to erase that which the editor rejects. Film doesn't.
      • Re:So (Score:3, Insightful)

        by Jeffrey Baker (6191)
        The Canon D1S does not "put any 35mm to shame". It takes pictures that are approximately as detailed as 35mm film, while solving none of the problems of an SLR and introducing all the problems of a digital sensor: chromatic aberration and aliasing, mainly. The Canon costs $8000! For that price you can buy a nice film camera ($1000), a few good prime lenses, and a shitload of film, plus airfare to the shoot and a nice meal afterwards, and some hookers.

        IMHO the Canon is a great camera but for the price i

    • Re:So (Score:5, Informative)

      by Anonymous Coward on Tuesday March 18, 2003 @01:47PM (#5537744)
      This isn't really analog-vs-digital, although digital processing is the easiest way to "decode" the image after its gone through the fancy lens.

      The advantage of this system over your Canon is that you can get high depth of field and large apertures at the same time. In order to increase the depth of field of your camera, you have to stop down the lens, which means less light. Less light means longer exposures (can't stop the action) or more sensitive film/sensors (more noise).

      Instead of stopping down the lens and blocking light, this only affects the phase of the wavefront which means all the light energy still goes through.

      Extremely clever.
    • Re:So (Score:3, Informative)

      by elmegil (12001)
      not have the leeway of doing photo processing tricks in the darkroom.

      Last time I checked, it was a hell of a lot easier to do photo processing tricks with photoshop than in a darkroom, and with experience and skill the two types of work can be hard to distinguish from each other. The only exception I can think of being "push" type processing which takes advantage of being able to stretch or alter the dynamic range of your medium (film or photopaper) beyond its ratings. Since the site appears

    • by Alkaiser (114022) on Tuesday March 18, 2003 @01:51PM (#5537775) Homepage
      For the hobbyist, this works out great. Not everyone has the resources necessary to get a drkroom going, and can't pull off all the tricks of the trade or for that matter develop their own film.

      I loved shooting pictures for the college newspaper, because that meant that whatever leftover film I had from the shoot, I could take those extra shots and develop those slides.

      Now, with digital, I never have to worry about developing film, or buying new film, so the cost of me getting a camera went down a significant amount. On top of that, I never had to worry that the shots I take didn't quite come out right. I have an instant look at the shot I had.

      Once the SLR bodies on the digitals go down in price a bit more, I'll be able to shoot pretty much whatever I was able to shoot with an analog camera. (With the exception of slide film.)

      Also, the digital camera is much more environmentally friendly. All those chemicals you use during processing gotta go SOMEWHERE.
      • For the hobbyist, this works out great. Not everyone has the resources necessary to get a drkroom going, and can't pull off all the tricks of the trade or for that matter develop their own film.
        That IS part of the hobby of photography. I don't know how much you paid for even a cheap digital, but you can get a used enlarger for about $75-100 and a canister/spool for $20. Then you need $20 worth of chemicals and $20 worth of tupperware and some cheap paper. Any 35mm will do, especially the one you get fr
    • Re:So (Score:5, Interesting)

      by Anixamander (448308) on Tuesday March 18, 2003 @01:57PM (#5537822) Journal
      Well for certain applications, this can suposedly do things your Canon doesn't have a chance in hell of doing. What comes to mind for me is indoor sports phtography. High shutter speed requires a wide open aperture (f2.8) to get enough light, but the upshot is minimal depth of field, making focusing on the fast moving subjects extremely tricky. I know this, I was a sports photographer in college. If this tech can truly eliminate depth of field issues, it would make that a hell of a lot easier. And no amount of dark room trickery will turn a blurred shot into a sharp shot.
      • Re:So (Score:2, Interesting)

        by ManxStef (469602)
        What comes to mind for me is indoor sports phtography. High shutter speed requires a wide open aperture (f2.8) to get enough light, but the upshot is minimal depth of field, making focusing on the fast moving subjects extremely tricky. I know this, I was a sports photographer in college. If this tech can truly eliminate depth of field issues, it would make that a hell of a lot easier. And no amount of dark room trickery will turn a blurred shot into a sharp shot.

        First off, you've missed out an important p

        • by mph (7675)
          So while I can see how this technology may have some advantages to modern photography, such as landscape work where maximum DoF is desirable (eg. Ansel Adams' style of photography, indeed he formed a group called f/64 specifically 'cause of the maximum DoF ethos...
          Camera movements (e.g. tilting the lens with respect to the film plane) are also invaluable if you want "here to infinity" depth-of-field. How I long for a nice 4x5 field camera...
      • I remember the agony of trying to capture some 'concept' Shakespeare plays at the theater (dimly lit), during a live performance using a Nikon with an f/3.5 zoom on 3200 T-Max. To get any depth of field required at least a half second exposure at a fat aperature. It helps to know the material - actors usually pause briefly after delivering a line (...inhale, snap).

        One of these cameras would have been fabulous - I could have actually put the rest of the cast in the yearbook - as it was only the leads were
    • by darkov (261309)
      I will be able to take a picture almost as good as the pictures I take with my 30 year old Cannon AE-1

      I think the point of the invention is that it can do in digital exactly what your old Cannon cannot do.

      I don't know why anyone modded your pretty lame troll up...
    • by 0x0d0a (568518)
      All I read was "interesting technique unavailable for 17 years (until the patent expires)".
  • Thundercats (Score:4, Funny)

    by Valiss (463641) on Tuesday March 18, 2003 @01:46PM (#5537733) Homepage
    So will this give us "sight beyond sight"?

    I'd settle for X-ray glasses.

  • by Anonymous Coward
    Clearer, more vibrant and detailed pr0n.
  • by Toasty16 (586358) on Tuesday March 18, 2003 @01:47PM (#5537739) Homepage
    ...now all they have to do is patent a technology that increases bandwidth 10-fold of the ISDN line that they are obviously hosting their server on.
  • by JeremyR (6924) on Tuesday March 18, 2003 @01:51PM (#5537774) Homepage
    Because the sensors used in digital cameras are typically much smaller than, say, a 35mm frame, the depth of field (DoF) at a given f-stop and "35mm equivalent" focal length is already much deeper than the DoF on a 35mm camera (at the same aperture and a comparable focal length).

    I guess an extremely deep DoF is preferable in some cases, but in a lot of photography, it is desirable to use a shallow DoF in order to throw everything other than the subject out of focus (making for a nice, pleasing, soft background and drawing attention to the subject). This is very difficult to do with small-sensor digital cameras.

    So I wonder if these "wavy lenses" can be used "in reverse" to narrow the depth of field for the purposes of enhancing creative DoF control?

    Cheers,
    Jeremy
    • by jandrese (485) <kensama@vt.edu> on Tuesday March 18, 2003 @02:10PM (#5537937) Homepage Journal
      Or you could just hit everything behind the subject with a blur filter. One of my favorite features of my digital camera is the long depth of field, which allows me to capture deep or unusually shaped objects with excellent clarity.

      In the end, I would rather have to throw away extra data rather than never have the data in the first place.
    • Although this might be true, the number of times you find youself with too little depth of field vastly outnumbers the number of times you end up with too little. Especially in shots where you lose it around the edges and you don't reaslise until the shot has been enlarged.

      Although it's a perfectly good technique, there are many other ways of getting the same results through composition that are more pleasing to the eye.
    • by mawdryn (531994) on Tuesday March 18, 2003 @02:48PM (#5538258)
      Having spent seven years as a commercial studio photographer (products and advertising, not portraits), I can say from much personal experience that more depth of field -- and more control over that depth of field -- is a very good thing. Even in a studio environment, where one can typically throw as much light on a subject as could be desired (allowing the use of very small apertures), achieving and controlling high depths of field can be a pain in the butt even for highly-controllable "analog" large format (4x5 and 8x10) cameras.

      I've never met a consumer-grade digital camera with decent aperature range or depth of field. IMHO the new "wavy lens" technology can only be of benefit. (Assuming it actually works.)
    • Canon, Kodak now have full-sized imaging chips that are 1:1 for 35mm film frames. Pricey but they are selling like hot-cakes.

      What we want is control of depth-of-field. Lenses produce different effect in the out-of-focus parts of the image. There are great debates about the quality of this part of the image. Some of the best lenses for great "bokeh" are made by Leica.
  • by 4of12 (97621) on Tuesday March 18, 2003 @01:59PM (#5537834) Homepage Journal

    I couldn't help but think back to the problem with the Hubble Space Telescope [nevada.edu], wherein after the launch they discovered that the mirror had not been properly ground to specification.

    • I couldn't help but think back to the problem with the Hubble Space Telescope [nevada.edu], wherein after the launch they discovered that the mirror had not been properly ground to specification.

      I think that's just Murphy's law.

      - "Everything ready to go?"

      - "Check, and double-check, sir!"

      - "Great, we'll launch in 10 minutes!"

      [15 minutes later...]

      - "You mean the checklist page is double-sided?!"
    • Totally unrelated to this story. That was spherical aberration, this is depth of field. Telescopes always view at effectively infinite depth of field, so this technology is not directly applicable to astronomy.
  • very cool (Score:5, Informative)

    by Anonymous Coward on Tuesday March 18, 2003 @02:00PM (#5537849)
    Ah yes, I know this system well. I did my master's research in extended depth-of-field optics and came across this research which pretty much blew away what I was working on.

    Here's a bit of background: in photography or laser scanning (point-by-point photography, basically), you always have a trade-off between depth-of-field and aperture size (as any photographer knows). Bigger aperture means shallow depth-of-field. However, a smaller aperture means lots of wasted light (imagine closing the aperture in your camera), and this means longer exposure times, and more importantly more NOISE in your images. This is true for digital, film, or photodetector.

    So the "holy grail" is to keep the aperture open but still have high depth-of-field. This system depends on changing the phase of the light, instead of the amplitude (which is what you do when you stop down a lens to a smaller aperture). That way, no light energy is blocked and wasted.

    Since the phase is changed, the resulting image on the CCD or film is fuzzy and has to be "decoded". You can think of it as "encoding" the wavefront in a special way that preserves the depth of field, capturing the image, and then "decoding" it into a sharp picture. It is really amazing. I hope it shows up in consumer cameras someday, it could completely change consumer photography since most "snapshot photographers" don't care about depth of field or all that stuff. It will also be great for medical and industrial imaging.

    My system was sort of a hybrid between shading the aperture (instead of a sudden stopping of light, it gradually goes to black at the edge) and phase changes. Lots of people have been working on this problem over the years, but these guys really stripped the problem down to the essence and came up with a highly optimized solution.
    • by .com b4 .storm (581701) on Tuesday March 18, 2003 @03:12PM (#5538440)

      I did my master's research in extended depth-of-field optics

      Was he a cruel master, or a tough but fair one? :) </lame>

    • Since the phase is changed, the resulting image on the CCD or film is fuzzy and has to be "decoded". You can think of it as "encoding" the wavefront in a special way that preserves the depth of field, capturing the image, and then "decoding" it into a sharp picture.

      When I first saw the article it sounded like the post-processing that is done to improve the focus of images that were originally taken out-of-focus. You can extract a lot of features by convolving an image with the inverse of the defocussing
      • by Hal-9001 (43188)

        When I first saw the article it sounded like the post-processing that is done to improve the focus of images that were originally taken out-of-focus. You can extract a lot of features by convolving an image with the inverse of the defocussing transfer function.

        But doing this has a downside: It also brings to a point focus, or nearly so, the light from patches of a certain range of shapes. They weren't originally points - but photographing them defocussed made the same shape blur as a point light source wo

  • So what does this do to my nice film scanner? Does this make my digital photography image chain unusable with the new technology? It seems unlikely that there's a Photoshop import filter for the original negative.

    And I'm always leary of adopting a new technology that is monopolized by a single provider.

  • What?! (Score:5, Funny)

    by return 42 (459012) on Tuesday March 18, 2003 @02:08PM (#5537920)
    A story...on Slashdot...about a patent...that's legitimate?
  • by jlowery (47102) on Tuesday March 18, 2003 @02:09PM (#5537923)
    Does anybody remember the deep focus cinematography of Gregg Toland? How were those shots done?
  • by Qzukk (229616) on Tuesday March 18, 2003 @02:13PM (#5537958) Journal
    I'm suprised, the USPTO actually managed to issue a patent for something new and innovative and unique, rather than for something thats been common practice for a few years.
  • NASA docking camera? (Score:3, Interesting)

    by Bazzargh (39195) on Tuesday March 18, 2003 @02:53PM (#5538305)
    havent been able to get to the site because of you lot bringing it down but... is this related to the technology used in NASA's docking cameras? I remember reading that they developed a camera that worked exactly as the /. story described, in order to combat the problem of losing focus on the target spacecraft during docking manoeuvers. The report I read was in New Scientist, probably 3 years ago?

    I'd go and find it but NS archives are subscription only. I really ought to get round to subscribing, I buy it often enough...

    -Baz
  • by dbc (135354) on Tuesday March 18, 2003 @02:58PM (#5538352)
    ... and I can't find out because the site is /.'ed :-(
    is this: Can this technology be used to control (not just increase, but also decrease) depth of field at image processing time? More specifically, can I get selective focus *after* creating the image? In criticizing my own work, I ususally wish I had openned up for *less* depth of field. I realize that sports photographers don't have this problem :-) but some of us nature photographers do.
  • by iblink (648486) on Tuesday March 18, 2003 @03:15PM (#5538462)
    Although Colorado University may never forgive me, this address has links to the research papers as well as more images: http://www.colorado.edu/isl/
    • Thanks for the links. It seems this system has a
      downside, namely it introduces its own artefacts,
      similar to ghosting. Look at http://www.colorado.edu/isl/intimages/focusinv.htm l
      and this will become clear. I wonder if this is
      inherent in their technique or just the imperfections
      of "1.0 release" of their tech.
  • Some more info from
    Boulderdailycamera [boulderdailycamera.com]

    Boulder startup gets deal with major optics player
    By Anthony Lane
    For the Camera

    A Boulder-based startup, which makes technology that greatly improves the clarity of images through a lens, is poised to grow after signing a deal with one of the world's premier lens and microelectronics makers.

    CDM Optics is a private company with sales last year of about $1 million, according to R.C. "Merc" Mercure, CDM's chairman and chief executive.

    Next year, sales are expected to do
  • by Anonymous Coward
    In case you were /.'d, most of the images from the CDM Optics website are also available here:
    more images of increased depth [colorado.edu]
  • More information (Score:2, Informative)

    by jimwatters (110653)
    Maybe just the same info because I have not been able to get through to the original links.
    Here is a news paper article.
    http://www.boulderdailycamera.com/busine ss/tech/27 bcdm.html

    and another.
    http://www.alteich.com/tidbits/t012802.h tm

    and some images.
    http://www.colorado.edu/isl/intimages/3co loredf.ht ml
  • "Economist" article (Score:4, Informative)

    by JPMH (100614) on Tuesday March 18, 2003 @06:01PM (#5539820)
    The Economist had a nice descriptive acticle about wavefront coding a couple of month ago. Interesting stuff.

    http://www.economist.com/science/tq/displayStory.c fm?story_id=1476751 [economist.com]

  • So? (Score:3, Informative)

    by KewlPC (245768) on Wednesday March 19, 2003 @03:14AM (#5542545) Homepage Journal
    Most photographers want LESS depth-of-field than the current crop of digital cameras provide.

    Only amateurs want "everything from here to infinity" to be in-focus.

    The advantages of selective depth-of-field cannot be understated. The ability to have the background be completely soft and have the subject be the only thing in sharp focus (thereby drawing the viewer's attention to it) is a huge advantage of film over digital.

    For example, on Attack of the Clones, the guys at ILM actually had to process the images to give them less depth-of-field, because the cameras couldn't get as little depth-of-field as the cinematographer wanted.

Nothing is more admirable than the fortitude with which millionaires tolerate the disadvantages of their wealth. -- Nero Wolfe

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