A lens is like a camera’s eye; while the image making happens inside the camera body and on the film itself, the lens is what handles the light and determines the quality of the resulting image. You can’t really hope to take a picture without a lens, unless you build yourself a pinhole camera, maybe, which is why it is important to understand how they work.
How does a lens work?
So in that spirit, let’s talk lenses. A lens is basically an assembly of different elements which help focus light onto the film and remove any aberrations. In a simple pinhole camera you can still make an exposure, but it will not be of high quality, appearing blurry and weird, and although this has its own quaint charm it is not always desired. Plus, you can’t increase the size of the hole and get a coherent image, and you have to wait a whole day to get any image with a small hole, so you see the problem.
In its simplest form a lens places a glass convex lens where the pinhole is, so the aperture can be opened wide to let more light in and make faster exposures, but the light can still be properly focused to get a sharp image. However, lens assemblies are more complex and have various other glass elements that help fine tune the quality of the image further.
The main factors that are used to define lenses are the focal length and aperture, which control the angle of view and amount of light respectively. Various lenses play with these two elements to make quality photographs for you.
Telescopic contact lenses and wink-control glasses
An estimated 285 million people are visually impaired worldwide. Age-related macular degeneration alone is the leading cause of blindness among older adults in the Western world. But this week at the AAAS Annual Meeting in San Jose, California, Eric Tremblay from EPFL in Switzerland unveils a new prototype of his telescopic contact lens—the first of its kind—giving hope for better, stronger vision. The optics specialist also debuts complementary smart glasses that recognize winks and ignore blinks, allowing wearers of the contact lenses to switch between normal and magnified vision.
The first iteration of the telescopic contact lens—which magnifies 2.8 times—was announced in 2013. Since then the scientists behind the DARPA-funded project have been fine-tuning the lens membranes and developing accessories to make the eyewear smarter and more comfortable for longer periods of time, and thus more usable in every day life.
[read more] [Photo Credit: Eric Tremblay and Joe Ford. Courtesy of EPFL]