jithu das chemistry of photography

1. CHEMISTRY BEHIND
PHOTOGRAPHY
PRESENTED BY : JITHU DAS MJ
KUCTE – KUMARAPURAM

2. Photographics filims are made
by coating silver-bromide
emulsion on transparent filim.

3. When the camera shutter is
opened, the light rays from the
object will fall on the film.

4. The presence of light silver ions on the
photographic films are converted to silver
atoms.
2Brˉ  Br2- 2eˉ
2Ag+ 2e-  2Ag

5. Depending on the intensity of light
falling on each part, the number of
silver atoms produced also varies…

6. For taking the photoprint, the film is
dipped in alkaline solution of
QUINOL.

7. •Thus the white part of the object
appears as black and vice versa

8. Negative is Dipped in Sodium thio
sulpahte solution.
It is then developed, washed and dried
to get the Photograph.

9. •
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