Annoyingly, neither this video nor pretty much any online resource really explains WHY this "pinhole glasses" technique works. However, I have read about pinhole cameras before, so I can provide a high-level explanation. Any lens works NOT by focussing a single image, but rather by aligning multiple images (really multiple paths of visible light) in such a way that they converge and form a single image on the receiving medium (either film, a light sensor, or your retina). A good lens focusses the multiple images formed by light coming in from all sides of the lens into a single image. A bad lens leaves multiple images at the point of "seeing". In the case of pinhole glasses or a pinhole camera, you can do without a lens, because you are minimizing the number of images coming through, leaving little chance for blur. In doing so, the image that DOES come thru is darker and lower in contrast than through a lens, and of course you lose all peripheral vision.
That is a very non-technical explanation, but I think it does the job of explaining why this cool experiment works.
Sunday, December 30, 2007
Emergency Glasses
Subscribe to:
Post Comments (Atom)
1 comment:
That is what F stop is on a camera. If you look inside of an old SLR you will see that when you close down the f stop, there is a bunch of shutters that close in a circular formation around the lens. This allows less light to get in and for you to have a longer amount of yardage of in focus objects. the more light you have, the smaller you can close down your f stop without degrading your picture. Thanks for the post, nomad.
Post a Comment