Film Processing Flashcards
(37 cards)
What are the four layers of film?
Protective layer
Emulsion
Adhesive
Base
What is the base layer made of? What is its purpose?
Flexible polyester plastic
Meant to support the delicate emotion and is coated on both sides
Double emulsion
What is the purpose of the adhesive layer?
Attaches the base to the emulsion
What is the purpose of the protective layer?
Protects the emulsion
Where is the emulsion located?
On either side of the base
What is the purpose of the emulsion and what is it made of?
Has a greater sensitivity to x-rays
Native silver halide crystals and gelatin
What is the purpose of the silver halide and gelatin?
Gelatin supports the halide crystals and absorbs chemicals to reach the crystals
Silver halide absorbs the radiation. Composed mostly of silver bromide (90%) and silver iodide (1-10%$
What is a latent image?
Invisible image of where the radiation has reached the crystals
Types of film
Intraoral
Extra oral
Duplicating film
Which side of the film faces the tube?
White side
“White in sight”
Which extra oral film uses less radiation?
Screen film. Emits rare earth light (green)
Describe extra oral cassettes
 soft or rigid. Rigid is more expensive
Light tight
Rigid = front cover is plastic, back cover is metal
How should film be stored
Cool dry place
No more than 70deg or 50% humidity
Lead lined container to prevent fogging
Do expire
Film speed
Faster film has larger crystals, is less sharp, requires less mA’s
Slower film has smaller crystals, is more sharp and requires more mA’s
Speeds A-F
What is the name of the chemical reaction where we make a visible image?
Reduction- halide portion is removed
Unexposed, unenergized crystals are removed from the film 
What is the developer responsible for
Reduction of energized crystals, turning them black. Unexposed Crystals stay the same
What does fixer do
Removes on energized crystals creating clear areas
Black is not removed and remains the same
Idea developer temp
68 degrees
No more than 80
How long does film sit in fixer?
Usually about double the time it’s in developer
How long do we was film for?
10 min
How do images become underdeveloped?
Developer is too cool
Developer was weak
Too little time developing
How do images become overdeveloped?
Developer is too warm
Too strong
Developer too long
What is reticulation?
Grainy, crackled look
Happens when you are shocking it with too big of a temperature change from developer to the wash
Developer spots
Film comes in contact with developer prematurely
Dark, over developed spots
