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An Origami Lens for Your Camera Phone?

ScuttleMonkey posted more than 7 years ago | from the interesting-folds dept.

Handhelds 69

Roland Piquepaille writes "Your next camera phone might get a new kind of lens if researchers at the University of California at San Diego convince the cell phones makers. They have designed an 'origami lens' which will slim high resolution cameras. Today, their 5-millimeter thick, 8-fold imager delivers images comparable in quality with photos taken with a compact camera lens with a 38 millimeter focal length. In a few years, these bendable lenses could be used in high resolution miniature cameras for unmanned surveillance aircraft, cell phones and infrared night vision applications."

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69 comments

no iPhone for me then... (0, Troll)

Gary W. Longsine (124661) | more than 7 years ago | (#17834322)

I can't see spending all that money on an iPhone unless it has this magic lens.

OK, just kidding there. :-)

Mods, learn to read! was: no iPhone for me then... (1)

Gary W. Longsine (124661) | more than 7 years ago | (#17843394)

I knew I was going to get in trouble for that witty remark. I even added "OK, just kidding there. :-)" so that the knuckle draggers amongst you might feel the Whump! of the clue stick. Alas, you plainly did not read the entire remark. Sigh.

Isn't this a Fresnel Lens? (0)

Anonymous Coward | more than 7 years ago | (#17834324)

Those have been around for hundreds of years

No, it's not even a lens (2, Informative)

spun (1352) | more than 7 years ago | (#17834396)

It's a reflector. Don't ask me how it works, the story and illustrations aren't very clear. But it's not a lens, fresnel or otherwise.

Re:No, it's not even a lens (1)

Lithdren (605362) | more than 7 years ago | (#17834536)

One does not use a lense to capture a soul.
One uses a crystal.

Be afrade, be very afrade!

Re:No, it's not even a lens (2, Insightful)

Jake73 (306340) | more than 7 years ago | (#17835054)

It's similar to how a reflecting telescope works. The mirror is a reflector, but operates similarly to a lens in how it can focus light. Just imagine collapsing a standard reflecting telescope several times onto itself. The most complicated part of it is the manufacturing which requires very precise control of the lens surface.

The advantage is, of course, the reduced thickness. These can be mounted on the skin of a surveillance device and not protrude like a lens would.

Re:No, it's not even a lens (1)

spun (1352) | more than 7 years ago | (#17835648)

I thought it was something like that. I am still having a lot of trouble visualizing the actual light-path, though.

Re:Isn't this a Fresnel Lens? (2, Informative)

Annirak (181684) | more than 7 years ago | (#17834502)

This is actually nothing like a Fresnel lens. Fresnel lenses are based on refraction and tend to give horrible image quality since they have a whole bunch of concentric rings. This lens does things a completely different way. It's really a pretty clever piece of optics. It's functionally equivalent to putting a conical reflector over the imaging device and another reflector at the edge or the lens. They just get a longer focal length by bouncing it up and down more.

who cares about image quality? (4, Funny)

User 956 (568564) | more than 7 years ago | (#17834564)

This is actually nothing like a Fresnel lens. Fresnel lenses are based on refraction and tend to give horrible image quality since they have a whole bunch of concentric rings.

You misspelled "burn the shit out of stuff"

Re:who cares about image quality? (0, Offtopic)

mordors9 (665662) | more than 7 years ago | (#17834688)

Actually this sounds like it will work great on my shoe tip camera that I use when walking around da Ladies :-) j/k

Re:Isn't this a Fresnel Lens? (1)

ozmanjusri (601766) | more than 7 years ago | (#17839544)

They just get a longer focal length by bouncing it up and down more.

I just tried this with my own camera.

You owe me a new Canon 350D.

Re:Isn't this a Fresnel Lens? (2, Informative)

Mogster (459037) | more than 7 years ago | (#17834548)

From TFA

To reduce camera thickness but retain good light collection and high-resolution capabilities, Tremblay and colleagues replaced the traditional lens with a "folded" optical system that is based on an extension of conventional astronomical telescopes that employed mirrors, such as the Cassegrain telescope, which was developed in 1672.
More here http://en.wikipedia.org/wiki/Cassegrain_reflector [wikipedia.org]

Re:Isn't this a Fresnel Lens? (0)

Anonymous Coward | more than 7 years ago | (#17834748)

RTFA:
"Our 'folded lens' is not technically a lens, since it is reflective. I am guilty of calling it a lens sometimes, but I'm trying to control myself. 'Imager,' or 'folded optic' are more accurate."

Misleading Summary (4, Informative)

tunabomber (259585) | more than 7 years ago | (#17834408)

Despite what the summary says, the "lense" isn't bendable. It just manages to compress a lot of light-bending capability into a small space by using reflective, rather than refractive optics and combining all the optics in a single crystal. I say "lense" because it's not refractive, so it's not really a lense.

Re:Misleading Summary (2, Informative)

SomeWhiteGuy (920943) | more than 7 years ago | (#17834488)

From the Article:

"Our 'folded lens' is not technically a lens, since it is reflective. I am guilty of calling it a lens sometimes, but I'm trying to control myself. 'Imager,' or 'folded optic' are more accurate."

Re:Misleading Summary (0)

Anonymous Coward | more than 7 years ago | (#17834542)

But why do you write "lense" when it's "lens"?

Re:Misleading Summary (0, Troll)

thelexx (237096) | more than 7 years ago | (#17835204)

It's a British thing I believe. Not supposed to make sense. Now where are my pens?

Re:Misleading Summary (0)

Anonymous Coward | more than 7 years ago | (#17836142)

No. Brits spell it "lens" too.

Re:Misleading Summary (1)

funfail (970288) | more than 7 years ago | (#17842068)

Not supposed to make sense
Is it supposed to make sens instead?

Re:Misleading Summary (1)

thelexx (237096) | more than 7 years ago | (#17852758)

Troll? Humour before swine...

Re:Misleading Summary (2, Funny)

elsilver (85140) | more than 7 years ago | (#17836236)

I say "lense" because it's not refractive

Oh, I got it, a lense is reflective, but a lens is refractive.

E.

they left that part out (1)

User 956 (568564) | more than 7 years ago | (#17834444)

They have designed an 'origami lens' which will slim high resolution cameras.

What they don't mention is that they had to fold space/time to do it.

Re:they left that part out (1)

mordors9 (665662) | more than 7 years ago | (#17834586)

Glad to hear Hiro is back in action.

imaging sensor chips (0)

Anonymous Coward | more than 7 years ago | (#17834460)

Imaging sensor chips are going to have to change too .. readout times need to increase so that we can have better dynamic range (in some applications) and overall much high FPS and frankly the only practical way I see that happening is by increasing the number of readout pins so that the chip surface area is divided into multiple (virtual) segments. That way the entire image can be read out much faster in parallel.

Cool, but... (4, Interesting)

harrkev (623093) | more than 7 years ago | (#17834466)

This looks pretty cool, but...

I see two disadvantages, and both of them relate to the fact that the light-gathering surface is now a donut.

The first is that the light-gathering ability is greatly reduced when compared so something else with the same width lens. On the plus side, if you are "shortening" your lens, you probably do not mind "fattening it up" in order to compensate. This also means that the lens cover on your cell phone cam will be bigger, so you have a larger area to get scratched, a larger area to wipe fingerprints off of before shooting, etc. No big whoop, but something to be aware of.

The second is that blurry objects tend to blur in the shape of the aperature. The classic picture of this is taking a picture of your sweetie standing in front of a Christmas tree covered with white lights. With a conventional lens, if the Christmas lights are blurry, they will tend to be little fuzzy circles. With the new lens, they will be little glowing fuzzy donuts. So this is probably not what you want for portrait work.

Still pretty cool, though. It will be interesting to see how this develops.

Cost benefit analysis... (3, Insightful)

Lord Prox (521892) | more than 7 years ago | (#17834760)

Something else to think about... cost of manufacture. If this is designed for small form factor it is most likely going into consumer electronics. If you are dropping several hundred bucks on a digital SLR you don't mind a big lens. Cost becomes an issue with $100 mass produced Taiwanese gadgets. This seems like it will cost a helluva lot more than a simple plastic standard lens. That only leaves a small market for expensive cameras with form factor restrictions. Or so it seems.

Silulu. Hot Polynesian Geek Chick. [scitechpulse.com]

Bullshit RTFA (2, Informative)

ghoul (157158) | more than 7 years ago | (#17835468)

They are only going to use the Diamond cutter to produce the master for the molded glass lenses. After the master is created cost of molding a plastic reflective imager is pretty much the same as cost of molding a plastic lens. They do need more software but we all know software is free as in beer Right?

^BumP^ (0)

Anonymous Coward | more than 7 years ago | (#17835700)

bumpy bump bump

Re:Cool, but... (1)

cbraga (55789) | more than 7 years ago | (#17834886)

Crappy phone lenses are fixed focus, so the christmas light defocused as a ring behind the subject will never happen as the camera focuses on something like 50 cm to infinity.

That only happens on non-fixed focus lenses that also have a large enough aperture.

ObSimpsons (4, Funny)

sconeu (64226) | more than 7 years ago | (#17835146)

I see two disadvantages, and both of them relate to the fact that the light-gathering surface is now a donut.

Donuts... Is there anything they can't do?

Re:Cool, but... (1)

Alef (605149) | more than 7 years ago | (#17835714)

I see two disadvantages, and both of them relate to the fact that the light-gathering surface is now a donut.

What if one where to attach two such "imagers" together? Shaping a spot into a donut, then back into a spot.

Re:Cool, but... (1)

harrkev (623093) | more than 7 years ago | (#17837860)

That falls into the "duh, why didn't I think of that?" category. That idea is just crazy enough to work! Of course, cost goes up, but that lens would be WAY cool! You, sir, deserved to be modded +10, genius.

Re:Cool, but... (0)

Anonymous Coward | more than 7 years ago | (#17838740)

So what happens if I take a picture of an actual glowing donut?

Great (5, Funny)

Mogster (459037) | more than 7 years ago | (#17834478)

From TFA

"This type of miniature camera is very promising for applications where you want high resolution images and a short exposure time. This describes what cell phone cameras want to be when they grow up," said Ford. "Today's cell phone cameras are pretty good for wide angle shots, but because space constraints require short focal length lenses, when you zoom them in, they're terrible. They're blurry, dark, and low contrast."
Great! Now we'll actually be able see the detail in the bloodshot eyes and puke dribbling down the side of the mouth of the clowns posting their latest drunken nightly outing on Flikr & YouTube. Those dark blurry images really put me off.

And don't get me started on the quality of the Britney/Paris upskirt pics....

Holy beavers, batman! (1)

spun (1352) | more than 7 years ago | (#17834926)

And don't get me started on the quality of the Britney/Paris upskirt pics....

The posts above and below yours mention how this kind of lens will produce a halo around out of focus highlights. Come on, who wouldn't want to see a naked, wrinkled beaver with a halo? OH GOD I JUST PICTURED IT! BLEACH! I NEED BLEACH FOR MY BRAIN!

Re:Great (1)

feed_those_kitties (606289) | more than 7 years ago | (#17834944)

And don't get me started on the quality of the Britney/Paris upskirt pics....

The final product is only as good as the original source material.

Re:Great (1)

Firehed (942385) | more than 7 years ago | (#17835616)

Oh shut up. You know you'd still hit it.

Re:Great (1)

iamstretchypanda (939837) | more than 7 years ago | (#17838310)

Oh shut up. You know you'd still hit it.

Too bad his hand would bitch at him for cheating
(Don't act like its not true O.o)

Re:Great (0, Offtopic)

Gary W. Longsine (124661) | more than 7 years ago | (#17843488)

Not to mention... how are comments moderated when mods don't read the comments?

Same tech can be used on SLRs (1, Interesting)

Anonymous Coward | more than 7 years ago | (#17834490)

Reflective telephoto lenses have been around for SLRs and movie cameras for ages. They are lightweight and produce nice "halos" for out-of-focus highlights such as light shimmering off of a lake or ocean in the background.

This technology can make such lenses much smaller and lighter and potentially much cheaper, allowing serious amateurs to add extreme telephotos to their camera bag without blowing their budget or lugging around heavy equipment.

Nice? (1)

caveat (26803) | more than 7 years ago | (#17842038)

Catadoptric, or mirror lenses, are almost universally regarded as having abominable bokeh [wikipedia.org] , which is why they're virtually never used. It's a subjective concept to be sure, but I'd say at leat 99% of pros and serious amateurs, people with an eye for these things, find the "donuts" of light to be nothing but horribly harsh, jarring, and distracting.

Focusing (1)

onix (990980) | more than 7 years ago | (#17834554)

Exactly how is focusing accomplished? Moving the reflector plane back and forth? Is it a conventional optic that it has fixed focal distance? Just curious.

Re:Focusing (1)

$RANDOMLUSER (804576) | more than 7 years ago | (#17834774)

From TFA:

The team is now designing variable-focus folded optical systems that have air between the reflective surfaces of the imager. Such imagers may be especially useful for lightweight, inexpensive infrared vision applications.
So I would take that to mean the current generation is fixed-focus.

Re:Focusing (1)

Tmack (593755) | more than 7 years ago | (#17834876)

Exactly how is focusing accomplished? Moving the reflector plane back and forth? Is it a conventional optic that it has fixed focal distance? Just curious.

Its basically combining the principles of a reflective telescope and a fresnel lens. In a reflective telescope, the parabolic curve of the primary mirror focuses the light onto another mirror that then reflects it through the eyepiece, which can be further focused to the proper setting by dialing it in or out. This has been compressed into this "folded optics" piece by thinning the mirrors and making the parabolic curve as a series of concentric rings much like that of a fesnel lens. By adjusting the curve of the parabola that the sections add up to, you can adjust the focal length of the system. This new optics piece also reflects between the primary and secondary several times, each time the light gets focused a little more than previously, and reflects towards the center aperture. The final focusing (if needed) could be accomplished by moving either the optic itself, or the CCD, or an intermediary lens. I state the "if needed" because chances are this will act much like the disposable 35mm cameras and have a fixed-focus setup, such that the CCD can be attached directly to the optic itself.

tm

Focal lenght and out-of-focus blur(bokeh) (1)

hkultala (69204) | more than 7 years ago | (#17839900)

The front page posting is wrong.

No cellphone camera has 38mm real focal lenght. They have focal length of about 5mm, which for 1/3" sensor gives same field of vision than 38mm in film camera.

This 5mm focal length lens is really not very big, but it does not have a very good aperture ( ie. area from where to gather light ).

The new "origami lens" does not make lenses smaller, but gives them bigger aperture.

There is however one very big drawbck in this design:

The "bokeh", ie form of out-of-focus softening is very ugly for mirror-typy lenses.

A dot focused correctly looks like dot.
A dot focused incorrectly with cheap traditional lens looks like soft filled rectangle, or soft filledpentagon.
A dot focused incorrectly with good traditional lens looks like soft filled hexagon or soft filled circle.

A dot focused incorrectly with mirror-lens(ie. this new origami lens) will look like a donut or tire.
(in this case maybe like tire of bicycle)

So except to see the background of the image full of circles..

Also the depth of good focus will be MUCH smaller with this lens, so there are much more out-of-focus stuff in pictures.

Re:Focal lenght and out-of-focus blur(bokeh) (1)

Dogtanian (588974) | more than 7 years ago | (#17841846)

I was always under the impression that the doughnut-shaped bokeh of mirror lenses was due to the second mirror blocking the centre of the main lens itself. But surely that doesn't apply in this case?

I think the "lousy" bokeh of mirror lenses is overstated. Sure, it's not desirable for every case, but it can be quite attractive under many circumstances.

Meanwhile, the Bokeh (of out-of-focus highlights) on the cheapish 28-80 zoom on my low-end Nikon SLR is a hard-edged circle, with most of the light around the edge, softly disappearing towards the centre. (See "Poor bokeh" [kenrockwell.com] here for an example). It's a decent lens otherwise...

Re:Focal lenght and out-of-focus blur(bokeh) (2, Insightful)

CityZen (464761) | more than 7 years ago | (#17851728)

This lens has exactly a second mirror blocking the center of the main lens itself.
Did you not look at the diagram? The thing blocking the aperture is the second mirror.
The "zone reflectors" are the 1st, 3rd, 5th, etc. mirrors.

Re:Focal lenght and out-of-focus blur(bokeh) (1)

Dogtanian (588974) | more than 7 years ago | (#17856632)

I misinterpreted the diagram due to it being in two dimensions (and not paying enough attention). I assumed there were two separate apertures at the top and the bottom, and that the whole construct was basically tube-shaped.

If that's not clear, it's hard to explain, but it's not important anyway; I realise now that the aperture was ring-shaped (having looked up "annular") and the whole thing was circular, with a large obstacle in the centre, making it similar to a traditional mirror lens.

Diffractive Optics (1)

pkulak (815640) | more than 7 years ago | (#17834794)

Canon has been doing this for a while, though it doesn't seem to be very compelling in SLR lenses. They are smaller, but Canon is charging quite a lot for that convenience and the optics don't seem to be quite up to the standards of their more-popular cousins.

http://www.usa.canon.com/consumer/controller?act=M odelDetailAct&fcategoryid=154&modelid=7468 [canon.com]

http://www.usa.canon.com/consumer/controller?act=M odelDetailAct&fcategoryid=150&modelid=9996 [canon.com]

I'm an idiot (1)

pkulak (815640) | more than 7 years ago | (#17834832)

Sorry, for some reason when I read "reflective" optics I thought "diffractive" for some reason. My mistake.

Telephoto Adapter (4, Funny)

Anonymous Coward | more than 7 years ago | (#17834822)

I want a telephoto adapter for my cell phone camera so I can use my cell phone as a tele-phone.

Sure, but at what price in quality? (2, Interesting)

Hawthorne01 (575586) | more than 7 years ago | (#17834840)

I'm not sure if I want something like this if it means it comes in at f11 or the like. Who wants a cameraphone that you can only use on sunny days, has a flash range that's measured in nanometers or comes with an ISO rating that requires scientific notation?

*IF* this can turn in f stops close to or equal to prime focus lenses or good quality zooms, for a reasonable price, then I'm interested. All those 75-300mm f5.6-f8 (or worse) lenses are useless, IMO, even with today's faster ISO chips/films. Gimme my old 180mm f2.8 any day.

Re:Sure, but at what price in quality? (1)

gordyf (23004) | more than 7 years ago | (#17835138)

I think you're missing the point -- this won't be replacing lenses on SLR cameras, it's meant for ultra-slim devices like cell phones where you wouldn't be using a large prime or zoom lens anyway.

Why origami? (0)

Anonymous Coward | more than 7 years ago | (#17835040)

Couldn't you just use a holographic lens to give you a flat, flexible lens? Granted, there are resolution limits for holographic lenses, but I bet they still exceed the resolution limits of the CCD in a cameraphone.

what about phase transformation? (1)

aleator (869538) | more than 7 years ago | (#17835108)

this is for sure an interesting movement. an old system (from the time of renaissance, IIRC) rediscovered and implemented with modern means.

what i find really interesting is how such a crystoptical system (origami lens sounds misleading and quite wrong, sorry) behaves in phase contrast transformation... if it's just mirrors of molecular thikness layers, then i would think that even aberrations can be eliminated... and this would lead not only to cheap mini-objectives but also to excellent reproducing objectives for professional photography... especially in the wide-lens range, where good optical systems are hard to make.

Here is how to get rid of Roland Piquepaille (4, Informative)

viking80 (697716) | more than 7 years ago | (#17835226)


Here is one of many greasemonkey script to remove piquepaille stories
http://userscripts.org/scripts/show/5735/ [userscripts.org] [userscripts.org]

Re:Here is how to get rid of Roland Piquepaille (0)

Anonymous Coward | more than 7 years ago | (#17835560)

You sir are a god among men. Thanks for the link! This was posted AC to avoid any karmic retribution.

Re:Here is how to get rid of Roland Piquepaille (1)

Zouden (232738) | more than 7 years ago | (#17840644)

But this is an interesting story, not a dupe, and Roland didn't provide a blogspam link. So what's the problem?

And why aren't you using that greasemonkey script?

what about the 'liquid lens'? (1)

ksheff (2406) | more than 7 years ago | (#17835274)

I thought the liquid lens [theregister.co.uk] was going to be revolutionizing the cellphone camera market? What are the image quality pros/cons between these two technologies?

Re:what about the 'liquid lens'? (1)

lindseyp (988332) | more than 7 years ago | (#17836974)

The liquid lens just allows refocusing by changing the shape of the lens. There's no benefit in high-aperture telephoto, which seems to be the main benefit of this new lens.

Basically, the benefit of this new technology is that if you want a longer focal length for the same aperture, you make the lens *wider* but not longer, making it suitable for telephoto or wide aperture photography where bulky lenses can't be used. i.e. compact cameras or cellphones.

Personally, I saw the drawing and recognised the concept immediately. All they've done is taken the reflector lens concept and extrapolated it. So simple anyone could have thought of it. But nobody did.

Simple, elegant, useful. fucking genius.

I saw such a thing from Halifax (1)

Easy2RememberNick (179395) | more than 7 years ago | (#17835718)

I remember seeing a guy on the local news who made a lens like that, maybe not exactly the same but I know it folded into very small sections. I know he was a University student in Halifax somewhere, but seeing that there are dozens of Universities in Halifax that's a bit vague.

  With a name such as Tremblay (a very common East coast Canadian name) it's probably the same guy, maybe he moved to the US.

Origami Lens and Diffraction (2, Informative)

opticsman (1058220) | more than 7 years ago | (#17835954)

This lens has the same problem as any lens-system with a central obstruction; the contrast for medium-scale detail is poor, due to diffraction effects.

Image quality is generally specified using a concept called Modulation Transfer Function (MTF). It is like a frequency response for lenses except the frequency is spatial in cycles per mm rather than Hertz.

Lenses with a central obstruction can have comparable MTF with respect to unobstructed lenses of the same speed, at spatial frequencies near the limit of resolution. However, you try very hard not to use a lens that way because the performance is poor. At the more important, intermediate spatial frequencies, an unobstructed lens has much better performance.

Astronomers have picked up on this idea. They like to use reflective lenses with a central obstruction for viewing stars where resolution limit is the only thing that counts and the perfect colour correction provides an advantage. However, unobstructed refractors are better for planets where you have a distributed image.

It is possible to make reflective telescopes without a central obstruction but the technology is still a little expensive. I expect, one day, they will displace refractors.

Aliasing is another issue using a centrally-obstructed lens with a pixellated image sensor like a CCD or CMOS device. Spatial frequencies above the Nyquist limit (2 pixels per cycle) generate garbage within the pass-band of the detector. A lens of this type concentrates its performance in the worst frequency range for the detector.

There are lots of promising approaches for cheap, compact lenses for cell-phone cameras but I doubt this lens is one of them.

advantage of reflective optics (1)

reversible physicist (799350) | more than 7 years ago | (#17835988)

The article didn't make one advantage very clear: since all colors of light are reflected identically, reflective optics can completely avoid chromatic aberration. This is precisely why Isaac Newton invented the reflective telescope. One reason that a good camera lens is heavy and expensive is because it combines elements with different refractive indices to try to minimize chromatic aberration.

firsT po5t (-1, Redundant)

Anonymous Coward | more than 7 years ago | (#17837038)

Here's an intersting (to me) idea- (1)

robbak (775424) | more than 7 years ago | (#17837282)

The lens is cut out of a crystal: What could we do with the piezo-electric effect on that crystal? Would it deform it enough to make the focus adjustable?
(The Piezo-electric effect, for those who came in late, is the deforming of a crystal when an electric charge is placed across it. It is used in some earpieces, some tweeters, and most buzzers used in computers. The reverse also occours: stress a crystal and a voltage is created. This is used in 'electret' microphone inserts.

Orientation (1)

Anonymous Cowdog (154277) | more than 7 years ago | (#17838440)

Camera makers should just change the orientation of their lenses, as Panasonic recently did with one of their models. I'd be surprised if their new approach gives more bang for the buck than that. Most cameras/phones have PLENTY of physical depth, it's just not used because of the way camera sensors are oriented.

just what i need (1)

jannesha (441851) | more than 7 years ago | (#17838542)

omfg. this is just what i need most in my life. a better quality camera in my cell phone.

no really, i need to take professional quality images WITH MY PHONE.

--p.

Annular lenses have terrible bokeh & low contr (1)

karlandtanya (601084) | more than 7 years ago | (#17841966)

I wanted a usable (f/8-f/11) 500mm telephoto for my film camera, but didn't have $6000 to spend on a high end one.
Wound up getting an old Reflex-Nikkor through ebay back when it was still somewhat honest.

My experience was that under the best conditions (bright light, no point sources), everything looks kind of muddy.
Other times--ex. shooting geese on a pond--the points of light reflecting off of the waves show up as hundreds of little donuts.

For it's size, the lens in the diagram has a much larger central obstruction--it's almost the whole lens.

Unless there's some funny business going on, I don't expect this to take a decent photo.

Old concept... (1)

advocate_one (662832) | more than 7 years ago | (#17842156)

look up Catadioptric lenses... here [wikipedia.org] . All they've done here is folded the light path a few more times... still the same concept though.
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