Slashdot Mirror
New Digital Camera Lens Made of Liquid
Clarinase writes "101reviews is running an article about a new type of camera lens called Fluidlens. This patented lens made of liquid is no bigger than a contact lens, but can still achieve up to 10 times optical zoom by changing its shape similar to the human eye."
"OIL LENS: hufuf oil held in static tension by an enclosing force field within a viewing tube as part of a magnifying or other light-manipulation system. Because each lens element can be adjusted individually one micron at a time, the oil lens is considered the ultimate in accuracy for manipulating visual light." -- DUNE, "Terminology of the Imperium."
This is right up there with those relatively small, sealed nuclear reactors, IMHO. Neat.
What you're actually doing is depriving the rods and cones in your eyes of blood. Similar to the nerves in your leg sending 'static' signals back your your brain when your leg falling alseep, your eye's start doing the same.
Incorrect. Squinting acts as a filter for scattered light (kind of like how those showboxes with the pinholes in them allow you to see an eclipse).
There was a guy a number of years back who sold "sunglasses guarenteed to improve your sight!" and all it was was a opaque plastic lens with hundreds of tiny holes in it.
To do any kind of zooming, you need 2 lenses, I believe, otherwise it's just a shift in focal points.
I'm certainly no expert on photography, but it seems to me that the maximum resolution doesn't have much to do with the size of the lens.
Maximum resolution has quite a lot to do with the size of the lens.
Sure, you can make a sensor with 50 million pixels on it, but if the resolution of the image coming through the lens only carries an equivalent of 1,000 or so lines horizontally and vertically, you're just going to be getting a very large file, not a high-resolution one.
(This is the scam already happening with a lot of 7mp and up consumer-level digicams - they just do not have the optics required to pass that level of detail.)
The larger a lens is, the more light it can let through. And that's all an image is to a camera - light. On film, that light hits the crystals contained in the celluloid and chemically excites them, whereas on a digital sensor the light is converted to binary data representing the image. In both cases, though, light is all that matters.
Bigger lenses can obviously gather more light, which means they can be used in lower-light situations or at longer focal lengths (longer focal lengths involve more light fall-off inside the lens, so it helps for extreme telephoto lenses to have massive front elements). It also means the sensor does not need to have its gain cranked up so high to compensate for a smaller lens. And it means the sensor itself can be larger, which in itself will allow greater resolution.
Probably the most important thing, though, is that larger lenses can more easily achieve perfect focus. It is possible for a lens to be simply unable to achieve perfect focus - the light beams will just never converge properly. This is not an exact science - every lens is slightly different in this (even among the same model), but larger lenses can come closer because they're dealing with the same projected image size but have more incoming light with which to deal and larger elements that can be built to stricter relative tolerances. This has the greatest effect on real resolution, and it's why some lenses appear tack-sharp and others look a bit soft.
Relatedly, the larger the lens, the less effect manufacturing tolerances are going to have on quality. For example, say an element can be ground to within 0.001mm of spec and still be within that spec. If you shrink the lens down by 100 times and you can still only manage a 0.001mm tolerance, you will not have any real consistency in quality. You would have to similarly up your manufacturing tolerances by 100 times just to maintain the quality of the larger lens.
This is even ignoring all the image defects you get from smaller lenses. Photographic lenses usually have 6 or more elements inside them to correct for various distortions that the curved glass introduces; obviously this is going to be a lot more difficult to do the smaller you go, and I can't see how a lens with liquid inside is really going to be able to simulate this. It might be able to replicate one or two interior elements (even though liquid is infinitely maleable, it can still only be one shape at a time) but I would imagine there will always be distortions left over.
You may ask how our eyes work so well, then, given how small they are. Well, for one thing, our eyes are "prime" lenses - they don't have an optical zoom function. For another, we have a big, powerful brain sitting behind them to interpret what we're looking at and correct any oddities (the image your eyes are actually seeing and the image you interpret are not even close to being the same thing). The fact that we've got two of them doesn't hurt either - it's not just about depth perception, just close one eye and see how good your vision is for a while. Peripheral vision will be cut, it is harder to focus, etc. Your brain does a good job of taking these two images and combining them, making it easier to see. Having two eyes also means we have double the light gathering ability.
Also, many people's eyes *don't* work so well.
I was looking to patent an idea like this. I created a liquid lense with oil and Iron-Oxide -- nothing really exotic, Ferro-fluids have been used for quite a while. In my design I used a combination of ionization and magnetism to shape the lense. It was only part of a more complicated idea--I didn't think the lense was worth a patent by itself--kind of obvious. The only reason this is useful now is that we have new technologies in video that can actually use such a tiny lense.
I was actually using this to move a laser to boost radio signals. I kind of gave up on the whole thing because I didn't have a job and didn't have any idea how to get the ball rolling. I'm an idea synthesizer-- not a lawyer. Anyway, I could have had about five patents out of this.
So, in short, this lense may possibly be as simple as mineral oil and rust surrounded by water between two pieces of glass (I haven't been able to read the article due to the "slashdot effect"). Inside the small area of water, surface tension works to hold the shape and relax the effects of gravity--It's best to have an oil of the same specific gravity as water (most are lighter) so that motion will not pull one liquid more than another. Still, unless you used a strong magnetic field on the ferro-fluid, motion would change its shape-- so no long exposures. The difference in light distortion between the water and the oil will allow for your lense to focus. My idea was to use two lasers--one as a reference beam to calculate unwanted distortions. I'm guessing there is going to have to be some feedback mechanism to determine what the spherical abberation of the resulting liquid lense would be. I wouldn't want to say anymore because it would then be easy to guess the tricks I figured out. Since I have nothing but a love of science and no degrees in the material sciences, the actual fabrication of this device would not be my forte.
On an aside, I still think it would be a nice idea to spin water in space to create a large lense for telescopic or sunlight collection purposes. About 30 years ago, when fiber optics first came out, I played with a lot of ideas for uses-- things like piping sunlight into the house, using it to peer inside the body and lase out blockages (I used a parasol design to stop blood flow and expand arteries--rather than a more obvious and more elegant balloon). It amazes me that things as obvious as a liquid lense can still find patentable uses.
I actually submitted this as an idea to a company that says it helps people with Inventions. When I got a follow call asking for $1200 more than the original $500 I realized it was a scam (sigh). If these scumbags realize they have prior art--I'm guessing they won't, since they are about scamming more than actually understanding any technology that people submit. Well, lessons learned. Nobody is going to "discover" your brilliance in life--everyone has to do their own leg work.
One of these days, I'd love to get back to inventing.
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