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Why can you get a negative image when light reacts with silver chloride?
Wiki User
∙ 12y ago
The light that makes the image on a film coated with silver chloride is absorbed by individual grains of solid silver chloride, and this absorption leaves the silver ions in an excited state, with more energy than the ions not exposed. The stronger the light, the more silver chloride grains in the image are exposed. When the exposed film is "developed", traditionally in a bath of sodium thiosulfate solution, the excited silver ions are reduced to metallic silver, which is black because it is so finely divided. Therefore the portions of the film that received the most light when forming the photograph become the darkest in the negative formed by development. When light is projected through the developed negative onto photosensitive print paper, the darkest areas of the negative allow very little light through them and the lighter ones allow more light, so that the lighter and darker areas are reversed again to form a positive image.
Wiki User
∙ 12y ago
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the name of the product formed when sodium reacts with potassium?
sodium chloride
Why is the image on a film a negative of the image photographed?
The light coming from the photographed object (not image) reacts to convert the silver bromide (AgBr, transparent colloid)) on the film into black (nontransparent) Ag crystals.This is the negative (reversed) image of the (positive) object.The same story with a dark object: no light, no Ag crystals = not black, still transparent!
what is the role of silver chloride and silver bromide in black and white photography?
On exposure to light both compounds forms silver metal in very finely divided state. Inside a camera the bright areas of the image projected onto a photgraphic plate or film are exposed more and therefore more silver gets deposited. This produces a "negative" of the image which is then used to produce the photograph.
How does photo development work?
is a chemical that makes the latent image on the film or print visible. It does this by reducing the silver halides that have been exposed to light to elemental silver in the gelatine matrix. As a generalisation, the longer a developer is allowed to work, the greater the degree of reduction of the silver halide crystals to silver and therefore the darker the negative image.
What is an image negative?
A piece of photographic film having the negative (opposite) image of your positive print or image.
What is silver chloride used for in the industry?
Silver Chloride is mainly used for making photographs. However, it is also used for many other things as well. Some of it's uses are: Used to make photographic paper since it reacts with photons to form latent image and via photoreduction. Silver chloride's low solubility makes it a suitable addition to pottery glazes. Used as an antidote for mercury poisoning assisting in the elimination of mercury. Is often used in photochromic lenses taking advantage of its reversible conversion to silver (Ag) metal. It's used to create yellow, amber, and brown shades in stained glass manufacture. It's used in bandages and wound healing products. Used as an antimicrobial agent in some personal deodorant products.
What happens when silver is exposed to sunlight?
When light shines on the silver chloride/albumin emulsion the redox reaction happens more quickly than it does in the dark. Imagine now a sensitized sheet of paper, half of which is exposed to bright sunlight and the other half of which is covered up with an opaque card. The silver ions in the exposed area will be reduced to black metallic silver in a matter of minutes; the silver ion under the card will remain colorless or white. Imagine now that you remove the opaque card; what will you see? The half of the paper that was in the light will be black and the half that was in the dark will be white. This reversal of light and dark is referred to as a negative image. But as soon as you remove the opaque card from the sensitized paper, the formerly unexposed white half will begin to turn black. In order to fix the image, we need to remove the light-sensitive silver chloride. Just washing it in water won't do the trick because silver chloride is insoluble in water. The earliest photographic fixer consisted simply of a concentrated solution of sodium chloride, ordinary table salt: While certainly convenient, this reaction does not go very far; only some of the silver chloride is dissolved and the rest remains on the paper. More effective than salt is ammonia.
Why do pictures come out negative in film rolls?
Film works by absorbing the light that hits it. The more light that hits an area on the film (meaning the brighter that part of the scene is), the darker the film will get. Slide film, which produces a positive image, works the same way. You get a positive image by developing the film, producing a negative image in the exposed silver grains, then developing the film again in a different developer that works on the silver grains not exposed in the camera.
Could you say that the dark image on the photographic film is due to fluorescence's?
no. photographic films contains silver iodide which converts to gray-black metallic silver via photoreduction. photoreduction is a light-dependent reaction which converts solar energy to chemical energy. when UV rays or visible light (basically sun rays) interacts with the silver chloride in the photographic film, photoreduction takes place. try pouring some silver chloride on a piece of white cloth, then leave it out in the sun, the area where the silver chloride is exposed to the sun will become dark coloured
What danguerre for photography?
Daguerre was an early pioneer in photography, around 1840. The Daguerreotype process produced a positive image made on a silver plated copper plate. Because this is a positive image on a metal plate only one image could be made from each exposure. *** Some say it's a negative image that appears positive because of the way the light reflects off of the polished surface that is behind the exposed and developed silver halide. I subscribe to this definition for two reasons: if you hold a daguerrotype on an angle just right, you can see the negative image, plus the image is reversed just like it is in a negative. See http://en.wikipedia.org/wiki/Daguerreotype and http://www.camerapedia.org/wiki/Daguerreotype_Process for this opposing view.
Could you say that the dark image on the photographic film is due to fluorescence why?
no, photographic films contains silver iodide which converts to gray-black metallic silver via photo reduction. Photo reduction is a light-dependent reaction which converts solar energy to chemical energy. when UV rays or visible light (basically sun rays) interacts with the silver chloride in the photographic film, photo reduction takes place. try pouring some silver chloride on a piece of white cloth, then leave it out in the sun, the area where the silver chloride is exposed to the sun will become dark coloured. (c) khim <3
What techniques are used within silent movies?
Pewter plates covered in Silver Nitrates. there were also techniques involving asphalt, which hardened under light. With silver, the plates would be sensitized with iodide, and then mercury vapors were used to develop the image and sodium chloride was used to fix the image.
