chemistry behind photography
Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Active In SP

Posts: 1
Joined: Oct 2010
13-10-2010, 07:20 PM

Please give me some information about chemistry behind photography in detail. I need it to make my presentation on the topic in my college. I am Animesh from Lovely Professional University, Phagwara, Punjab, India.
I am a first year student in ECE. I will be very kindly to you if you send me some useful material which may help me for my project and implimentation.
seminar surveyer
Active In SP

Posts: 3,541
Joined: Sep 2010
22-10-2010, 11:33 AM

Photography & Chemistry
Photography encompasses many things – there is a science to photography, but as a means of expression, it is ultimately an art form. There are many techniques and forms of photography which fill many books in the library and many pages on the Internet. Beyond this point, the actual taking of pictures, style, and good composition will not be mentioned again. Chemistry is an even larger subject area, encompassing all areas of life and invisible details that are often mind boggling. To couple photography and chemistry is narrower than either subject on its own, but still includes a lot of material. These pages will look at some basics, presenting only a small fraction of the information relevant to the chemistry of photography.

The Latent Image and Image Development
The silver halide process is by far the most important of all of the radiation-sensitive photographic systems in use today. The principal reason for this superiority is the high sensitivity of the system - the amount of radiant energy required to produce a useful image – and the extreme flexibility of the system in terms of adjusting sensitivity, contrast, tonal range and other such aspects of the product. The impact of a single photon on a silver halide grain, for example, produces a nucleus of at least four silver atoms, and that effect can be amplified as much as a billion times by the action of a properly chosen reducing agent or "developer."
The silver halides employed are silver bromide, silver chloride and silver iodide. The first two may be used separately or combined, depending on the sensitivity and tonal qualities desired in the product. Silver iodide is always combined with silver bromide or silver chloride.
As already noted, the silver halides used in photography are dispersions of microscopic crystals in a colloidal binder that is usually bone gelatin. Although such dispersions are referred to as emulsions or photographic emulsions, they are really dispersions.
When an exposed film is placed in a developer solution, the grains that contain silver nuclei are reduced much faster than those that do not. The more nuclei present in a given grain (i.e., the greater the exposure of that grain), the faster the reaction with developer and the darker the image at that site in the film. Factors such as temperature, concentration of the developer, pH, and the total number of nuclei in each grain determine the extent of development and the intensity of free silver (blackness) deposited in the film emulsion in a given time.
Not only must the developer be capable of reducing silver ions to free silver, but it must be selective enough not to reduce the unexposed grains, a process known as "fogging," within the time frame of the development process. Some substances that are commonly used as silver halide developers are listed in Table 1.
The developer is oxidized in the process. If not properly protected it can also be oxidized by air, a process that, if not prevented, will result in the loss of developer activity. To help prevent such effects, commercial developer solutions commonly contain preservatives such as sodium sulfite.



Important Note..!

If you are not satisfied with above reply ,..Please


So that we will collect data for you and will made reply to the request....OR try below "QUICK REPLY" box to add a reply to this page

Quick Reply
Type your reply to this message here.

Image Verification
Please enter the text contained within the image into the text box below it. This process is used to prevent automated spam bots.
Image Verification
(case insensitive)

Possibly Related Threads...
Thread Author Replies Views Last Post
  free downloadpuri sharma pathania physical chemistry pdf Guest 2 80 31-10-2016, 03:06 PM
Last Post: jaseela123
  kirlian photography seminar report Guest 1 80 31-10-2016, 12:27 PM
Last Post: amrutha735
  chemistry investigatory project on drugs and medicines Guest 2 138 31-10-2016, 10:52 AM
Last Post: anusree
  boron chemistry and application to cancer treatment pdf Guest 1 408 31-10-2016, 09:16 AM
Last Post: anusree
  free downloadpuri sharma pathania physical chemistry pdf Guest 1 50 29-10-2016, 12:51 PM
Last Post: jaseela123
  free downloadpuri sharma pathania physical chemistry pdf Guest 1 44 29-10-2016, 11:01 AM
Last Post: ijasti
  free downloadpuri sharma pathania physical chemistry pdf Guest 2 230 11-10-2016, 04:29 PM
Last Post: amrutha735
  download ppt on environmental chemistry class 11 Guest 1 78 08-10-2016, 03:47 PM
Last Post: Dhanabhagya
  green chemistry questions Guest 1 63 08-10-2016, 03:19 PM
Last Post: Dhanabhagya
  free ebook of puri sharma kalia inorganic chemistry Guest 1 124 14-07-2016, 03:56 PM
Last Post: Dhanabhagya