Free Republic

I am 88 and need Cataract Surgery. I am very active and want to continue to wear glasses for eye protection for my varies hobbies (Carpentry, auto repair, etc). I am nearsighted and have always worn glasses. I prefer single focus Lenses - should go for "Near" new Lens them adjust with new glasses or "Far" then adjust with new glasses. ...or give your best recommendations that you have from your own experience!

During CNN’s coverage of the Georgia Senate runoff on Tuesday, Sen. Amy Klobuchar (D-MN) reacted to Sen. Raphael Warnock’s (D-GA) victory in the runoff by stating the Warnock win was because “the state saw through whatever political lens they had” or “everything everyone’s been through with COVID and inflation all over the world. And they said, you know what, I believe Raphael Warnock is going to have my back and he’s going to help our country and he’s the right guy in terms of our democracy.” Klobuchar said, “A lot of this has to do with Donald Trump, I agree....

In the far future, we could reveal detailed views of distant worlds by turning our home star into a gravitational lens Diagram showing a conceptual imaging technique that uses the sun’s gravitational field to magnify light from exoplanets. This would allow for highly advanced reconstructions of what exoplanets look like. We now know of more than 5,000 exoplanets beyond the solar system. What we really understand about each of these worlds, though, is barely anything at all. Most of them have been seen only indirectly from their shadows as they cross in front of the stars they orbit. The...

What a Perfect Gravitational LensA stunning new photograph from the Hubble Space Telescope shows a nearly perfect Einstein Ring, an effect caused by gravitational lensing. This is one of the most complete Einstein Rings ever seen. Gravitational lenses occur when a massive object, such as a galaxy, is aligned directly between Earth and another massive object even farther away. Einstein predicted that gravity could bend light, and this image is a wonderful example of how gravity from foreground objects causes a deflection of light from background objects, forming a ring of light.In this case, it’s not just one foreground...

Despite all the advances in consumer technology over the past decades, one component has remained frustratingly stagnant: the optical lens. Unlike electronic devices, which have gotten smaller and more efficient over the years, the design and underlying physics of today's optical lenses haven't changed much in about 3,000 years. This challenge has caused a bottleneck in the development of next-generation optical systems such as wearable displays for virtual reality, which require compact, lightweight, and cost-effective components. At the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS), a team of researchers led by Federico Capasso, the Robert L....

A Neutrino Beam Beaconby Paul Gilsteron May 17, 2019 If you want to look for possible artifacts of advanced civilizations, as do those practicing what is now being called Dysonian SETI, then it pays to listen to the father of the field. My friend Al Jackson has done so and offers a Dyson quote to lead off his new paper: “So the first rule of my game is: think of the biggest possible artificial activities with limits set only by the laws of physics and look for those.” Dyson wrote that in a 1966 paper that repays study today (citation...

A flat lens made of paint whitener on a sliver of glass could revolutionise optics, according to its US inventors. Just 2mm across and finer than a human hair, the tiny device can magnify nanoscale objects and gives a sharper focus than top-end microscope lenses. It is the latest example of the power of metamaterials, whose novel properties emerge from their structure. Shapes on the surface of this lens are smaller than the wavelength of light involved: a thousandth of a millimetre. "In my opinion, this technology will be game-changing," said Federico Capasso of Harvard University, the senior author of...

Just over a year ago, we introduced Office Lens for Windows Phone—and over that time the app has become one of the most popular free apps on Windows Phone, with an average rating of 4.6 stars (out of 5) from more than 18,500 reviews. Today, we’re releasing Office Lens for iPhone and Android phones. Office Lens is a handy capture app that turns your smartphone into a pocket scanner and it works with OneNote so you’ll never lose a thing. Use it to take pictures of receipts, business cards, menus, whiteboards or sticky notes—then let Office Lens crop, enhance and...

Another of the old Minolta classics to play with. It's a constant f4.5, highly rated for IQ and really compact. This may just be my new favorite walkaround lens.

Drawing heavily upon nature for inspiration, a team of researchers has created a new artificial lens that is nearly identical to the natural lens of the human eye. This innovative lens, which is made up of thousands of nanoscale polymer layers, may one day provide a more natural performance in implantable lenses to replace damaged or diseased human eye lenses, as well as consumer vision products; it also may lead to superior ground and aerial surveillance technology. This work, which the Case Western Reserve University, Rose-Hulman Institute of Technology, U.S. Naval Research Laboratory, and PolymerPlus team describes in the Optical...

Just back from the doctors office, got the wrapper off of my left eye. When everything settles down I'm gonna have close to 20/20 in both eyes!It's a different world and it sure is pretty!

We have heard a lot about exoplanets in the past year. But for all the talk about these planets, which orbit a star other than our sun, we still haven't actually seen one. One tool could change that, giving us our first look at a distant planet that could be the next best thing to Earth. Currently, scientists detect an extra-solar planet by measuring the dimming of its star as the planet passes between it and our line of sight (this is known as the Transit Method). By observing the way the star's light shines around the planet, it's possible...

It's a given in bird and critter photography that closer is always better but a big lens will work too.This is a Sigma 400mm f5.6 in Minolta A mount. In this pic it's on my Minolta Maxxum XTsi but it also fits my Sony. On the Sony it is equivalent to 600mm.This lens was made in the mid 80s but can pass for new, not a blemish on it anywhere.

SOMETIMES all it takes is a quick hug, and everything looks different. Now a shape-shifting lens has been developed that alters its focal length when squeezed by an artificial muscle, rather like the lens in a human eye. The muscle, a ring of polymer gel, expands and contracts in response to environmental changes, eliminating the need for electronics to power or control the devices. "The lenses harness the energy around them to control themselves," says lead researcher Hongrui Jiang at the University of Wisconsin-Madison, US, where the device has been developed (Nature, vol 442, p 551). "This would be useful...

amed Fluidlens, this lens is made of liquid and is no bigger than a contact lens, but can achieve an optical zoom of up to 10 times, matching the zoom capabilities of lenses found on mid-range and high-end digital cameras and superior than most cellphone cameras which use digital zoom that relies on software rather than the lens to zoom in on an object. This liquid lens system achieves optical zooming through altering its focal length by changing its shape which mimics the action of the human eye. “Currently there is no practical alternative to compensate for the fixed focus...

Scientists at Canada's Universite Laval have invented a lens that is five times thinner than a piece of paper and can zoom without using mechanical parts. The lens is created by adding a small quantity of photosensitive material to a liquid crystal cell. When a weak electrical current is applied, the crystals realign differently from those in the periphery and thus take on the shape and behavior of a lens. The researchers have been able to modify the lens’ focal distance from 1.6 to 8 meters in a few milliseconds by increasing the voltage from 1.5 to 4.5 volts.

Summary - (Apr 29, 2005) Gravitational lensing happens when the gravity of a relatively close galaxy acts as a telescope lens to focus the light from a more distant galaxy. It allows astronomers to see distant objects they could never have a hope of observing with current instruments, essentially looking back to moments after the Big Bang (cosmically speaking). The galaxies are never perfectly lined up, though, and the "natural telescope" is a bit blurry. But now astronomer Remi Cabanac has found one of the most complete lenses ever discovered: a near perfect Einstein Ring, magnifying a distant galaxy with...

Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2003 January 8 Abell 1689 Warps Space Credit: N. Benitez (JHU), T. Broadhurst (Hebrew Univ.), H. Ford (JHU), M. Clampin(STScI), G. Hartig (STScI), G. Illingworth (UCO/Lick), ACS Science Team, ESA, NASA Explanation: Two billion light-years away, galaxy cluster Abell 1689 is one of the most massive objects in the Universe. In this view from the Hubble Space Telescope's Advanced Camera for Surveys, Abell 1689 is seen to warp...

Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2002 November 27 Leonids and Leica Credit & Copyright: Juan Carlos Casado and Isabel Graboleda Explanation: This lovely view from northern Spain, at Cape Creus on the easternmost point of the Iberian peninsula, looks out across the Mediteranean and up into the stream of the 2002 Leonid meteor shower. The picture is a composite of thirty separate one minute exposures taken through a fisheye lens near the Leonids' first...

Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2002 July 8 Weighing Empty Space Credit & Copyright: Bell Labs-Lucent Technologies, AURA, NOAO, NSF Explanation: Sometimes staring into empty space is useful. Pictured above is a region of sky that was picked because it had, well, nothing: no bright stars, no bright galaxies, and no picturesque nebulas. What could not be avoided, however, were a few stars in our own Galaxy, and many distant galaxies strewn across...