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Wavy Lenses Extend Depth of Field in Digital Imaging
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."
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
That wouldn't take long to saturate the processor. If it were flat html with images, it would just max out the network.
I hope the heatsinks work!
I couldn't help but think back to the problem with the Hubble Space Telescope, wherein after the launch they discovered that the mirror had not been properly ground to specification.
"Provided by the management for your protection."
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.
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.
ZFS: because love is never having to say fsck
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.
ZFS: because love is never having to say fsck
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.
-[Blaine]- "'Oh dear,' says God, 'I hadn't thought of that,' and promptly vanishes in a puff of logic."
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, and these formats are also used in several high-end 3D renderers, but I don't think they will become mainstream until Photoshop adopts them.
Unfortunately, Adobe insists on minor updates instead of doing what Photoshop (and Premiere, and several other of their products) needs, which is a complete rewrite.
High-end 3D renderers also have very good "film grain" simulation (film grain is not just random noise, it has very specific characteristics), and other tricks that can make CGI "feel" almost exactly like traditional analog media. But again, this is not something you'll find in Photoshop.
RMN
~~~
and: http://www.luminous-landscape.com/reviews/cameras
It's just polite to make such links both active and accurate (extraneous spaces in both links -- probably inserted by slashdot because you tried to submit the URLs as plain text).
Sometimes boldness is in fashion. Sometimes only the brave will be bold.
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/
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 channel, as opposed to the current 256/channel in a standard 24 bit image.
It's still an RGB system, but it's a much better RGB system.
The next step is to get manufacturers on board & start making HDRI Video Cards & Monitors.
What were you expecting?
Some more info from
Boulderdailycamera
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 double with CDM's new partnership with the optical engineering company Carl Zeiss, a renowned manufacturer of microscopes, lenses and other instruments.
"The world's oldest optical company has joined forces with the most modern," said Ed Dowski, vice-president of CDM Optics.
The moving parts and multiple lenses of microscopes and certain cameras are precisely engineered to control aberrations and to produce a sharp image where someone wants it -- on a piece of paper, a slide or a computer screen.
Over centuries, scientists have devised ways to make sharp images of ever-smaller and more distant objects, but could do little to overcome the unchanging rules governing light and the formation of a focused image.
"There were no revolutionary changes in optics for 200 years," said Dowski.
CDM Optics produces an unusual type of "lens." Added to a standard lens, it produces images that actually appear blurry.
In fact, "There doesn't seem to be any part of the image that is more focused than any other," said Mercure, who was the co-founder of Ball Brothers Research Corp., which became Ball Aerospace.
A uniformly unfocused image may seem an unlikely goal, but after being digitally processed, the result is an image that is entirely in focus.
Mercure holds a poster with four pictures of a pack of crayons. Two were produced with a standard digital camera and the other two with a digital camera equipped with CDM's Wavefront Coding technology.
In one of the images from the standard camera, only a few crayons in the middle of the pack are in focus. To bring more of the crayons into focus, the photographer would have to decrease the size of the hole through which light enters the camera.
In the resulting image, more crayons are in focus, but it appears grainy as a result of less light hitting the camera's digital detector.
The difference between the two pictures produced with CDM's technology is more dramatic. The first is hazy -- it is an unprocessed image that would not ordinarily be seen.
In the second picture, all of the crayons from front to back are in focus without the graininess from the standard camera.
Dowski said applications for the technology that allows lenses to produce such images are numerous.
"You can either make lenses cheaper, sharper or both," he said.
Sharper images may be beneficial for many types of optics. A microscope, for instance, may magnify an object to 100 times its actual size with only a sliver 1 micron thick in focus.
"We can give a microscope up to 15 microns of focus," Mercure said.
One area in which this improved depth of field might be useful is in vitro fertilization. Ordinarily, a doctor produces a great number of embryos and monitors them for several days before implanting several. The goal is cause a successful pregnancy while minimizing the number of multiple births.
The problem is that after about three days, embryos are difficult to monitor with an ordinary microscope. The embryologist must guess which embryos are most likely produce a successful pregnancy.
Using Wavefront Coding technology, Mercure said, embryologists should be able to monitor the embryos for four or five days, thus reducing the number of embryos that must be implanted to have the same chance of a successful pregnancy.
The same increase in depth of field
"He is no fool who gives what he cannot keep in order to gain what he cannot lose."
Some of them are these days (wow! talk about low yield wafers!)
I doubt its that bad, since a camera can deal with a sparkling of 'dead' sensors, while pretty much any defect will kill a CPU.
autopr0n is like, down and stuff.
In case you were /.'d, most of the images from the CDM Optics website are also available here:
more images of increased depth
Maybe just the same info because I have not been able to get through to the original links.e ss/tech/27 bcdm.html
h tm
o loredf.ht ml
Here is a news paper article.
http://www.boulderdailycamera.com/busin
and another.
http://www.alteich.com/tidbits/t012802.
and some images.
http://www.colorado.edu/isl/intimages/3c
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
The only title of honor that a tyrant can grant is "Enemy of the State."
http://www.economist.com/science/tq/displayStory.c fm?story_id=1476751
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.
John
"It take 9 months to bear a child, no matter how many women you assign to the job."
Since the corporate site is still down, the best place to read about this is probably the website of the Imaging Systems Laboratory at the University of Colorado at Boulder, which I think is where all this technology was originally developed. Someone else posted that link elsewhere in the comments, but I will post it again here, properly hyperlinked for convenient Slashdotting.
"It take 9 months to bear a child, no matter how many women you assign to the job."
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.