6 Flashcards
This refers to a cellulose tape or plate where silver salts are suspended that
are capable of recording light. It is only a fraction of an inch thick, yet it is made of
many layers.
Film
The thickest part is a clear plastic base which holds the rest together
Film Structure
Structure of Black – and – white film
- Top Coating/Varnish Coating/Protective Coating
- Emulsion Layer/Inert Gelatin –
- Film Base/Backing/Base
- Anti – halation Backing/Anti – Curl
- Structure of Color Film
– This refers to top layer;
scratch – resistant coating; gelatine coating; an over – coating composed of a thin
transparent layer of hard gelatine which helps protect the silver halide emulsion from
scratches and abrasions
Top Coating/Varnish Coating/Protective Coating
– This refers to structure of film that composed
of silver halides and gelatine – a layer composed of silver compounds (which are light
sensitive) and halogens (such as bromide, chloride, and iodide which is used in small
amounts, seldom made more than 5% with silver bromide in fast film emulsion).
Emulsion Layer/Inert Gelatin
– This refers to structure of film that is made of
cellulose acetate or other materials such as paper, plastic, or glass which supports the
emulsion layer and is coated with a non – curl anti – halation backing
- Film Base/Backing/Base
– This refers to a black dye applied on the
rear surface of the film, it absorbs light that may penetrate the emulsion layer to prevent
it from reflecting back to the emulsion thus making the mage sharper since it suppresses
double image, and prevents the appearance of halo formation in the photograph.
- Anti – halation Backing/Anti –Curl
– This refers to emulsion layer that consist of three
(or four) layers stacked one on top of another with filter in between each. These separate
layers record the green blue and red values that go on making all colors, because all colors
can be made of mixtures of red, blue and green which are called primary colors.
Structure of Color Film
– This refers to scratch resistant coating
Top Coating
– This refers to a sensitive to blue light only; green and red light
passes through it without exposing the color halides.
Blue Filter
– This refers to Carey – lea silver suspended in gelatin – it is
coated between the top and second layer to absorb any penetrating blue light but
allowing green and red light to pass through.
Yellow Filter
This refers to a layer that is orthochromatic; the layer sensitive
to blue light (which cannot reach it) and green, but not to red; red light passes on the
bottom of the emulsion layer.
Green Filter –
– This refers to a panchromatic layer, sensitive to blue and red. It is
also somewhat sensitive to green light but to such a slight degree that is not important
Red Filter
– This refers to plastic film base
Film Base
Typology of Films
a. According to Use
Black and White Film
Color film
X-ray film
