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Flashcards in Midterm 2 Deck (61)
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1

List the darkroom essentials

Film processors
Loading bench
Film bin
Film identification printer
Safelights

2

Safelights must not exceed ___ watts

15

3

Safelights must be at least ___ feet away from work area

4

4

Undeveloped film must not be exposed to safelights more than ___ minutes

3

5

Safelights usually only allows light from the ____ end of visible light spectrum?

Red (GBX filter)

6

_______ consists of incrementally exposing undeveloped film to dark room conditions in 30 sec intervals for up to 3 minutes.

Safe light test

7

What are the steps of film development?

Exposure
Development
Fixing
Washing
Dry

8

What part of film development/image creation is when the film is exposed to light?

Exposure

Note: 99% of the image is created by light emanated by screens. 1% or less comes from direct exposure of silver halide crystal by an x-ray photon

9

Exposure of the film causes silver bromide crystal to what?

Separate into a silver ion and a bromine ion

10

What step of film development is the latent image created?

Exposure

11

What does the developer do in film development?

Donates electrons that create elemental silver

Note: black in color

12

Between developer and fixer, what happens?

Wash stop bath to remove excess developer

13

What does fixer do in film development?

Remove unexposed silver halide crystals from emulsion.

Permanently stops exposure beyond what has been done prior to developer

14

What does the final wash do in the film development process?

Clears all chemicals on the film surface and emulsion.

Prevents fixer chemicals from continuing to cause chemical changes to emulsion after the finished product has been produced.

15

What happens in the film development process if washing was not good enough?

Overtime the film degrades: brown color, acetic acid smell, etc

16

What pH is developer?

pH 10-11.5, strong base

17

What is in developer?

Activator
Reducing agents
Preservative
Restrainer

18

What does “activator” do in developer solution and what is it?

Sodium carbonate

Softens gelatin protective cover on film, Makes alkaline pH at >7

19

What do the “reducing agents” do in developer solution and what is it?

Hydroquinone or Phenidone (Metal or Elon)

Reduces EXPOSED silver halide to black metallic silver

20

What does the “preservative” do in developer solution and what is it?

Sodium sulfite

Prevents oxidation

21

What does the “restrainer” do in developer solution and what is it?

Potassium bromide, acetic acid

Prevents chemical fog in new developer

22

What is in the fixer solution?

Clearing agent
Tanning agent
Activator

23

What does the “clearing agent” do in fixer solution and what is it?

Ammonium thiosulfate

Dissolves undeveloped silver halide, removes it from emulsion

24

What does the “tanning agent” do in fixer solution and what is it?

Potassium alum

Shrinks, hardens, preserves emulsion

25

What does the “activator” do in fixer solution and what is it?

Acetic acid

Neutralizes developer, stops the development process, maintains acid pH

26

Processing is a function of 3 T’s

Time
Temp
Titration (chemicals)

27

What causes film overdevelopment?

Increased time, temp or titration.

Note: overdevelopment = darker film

28

Film overdevelopment is caused by processor-induced fog which is the forced development of

unexposed silver halide crystals by too much processing

29

Manual processing: ___˚F, and list time for development, fixer, wash, dry

68˚ F
5 min development
10 min fixer
20 min washing
20-40 min drying

Summary: estimated 1 hour total for each film in manual processing

30

Automatic processing: temp ____ ˚F and ave. time ____ mins

92-96˚F
1.5-3 mins