Film Unsharpness (4)

Question 1

Define Inherent Unsharpness

Answer 1

Scatter can occur within the film emulsion itself, causing a loss of image definition.

Direct result of secondary electrons generated in the film emulsion, rendering the silver halide grains developable.

Question 2

Factors that impact level of Inherent Unsharpness

Answer 2

• The graininess of film (size of silver halide crystals)
• higher energy radiation (regardless of film grain size)
• duration of film exposure

Question 3

Define Graininess

Answer 3

The size of the silver halide grains and how they are clumped together in a processed radiographic emulsion.

Question 4

Faster and coarser grained films will exhibit the ____ degree of graininess - a grainier looking image of lower resolution

Answer 4

greatest

Question 5

Degree of Graininess is dependant on:

Answer 5

1. Size of silver halide grains
2. how grains are clumped together in a processed emulsion
3. quality of radiation used (more energetic = increased graininess)

Question 6

Film Classifications

Answer 6

Class 1/Type 1 :

• Higher film speed
• larger grain size
• low level contrast

Question 7

Define Film Contrast

Answer 7

Differences in radiographic density from type of film, how film was exposed and film processing variables

Question 8

If a film is exposed longer to produce higher (darker) film densities, the amount of contrast present will ___ ____.

Answer 8

also increase.

Question 9

Define Latitude/dynamic range

Answer 9

The ability of a film to cover a range of thicknesses for a given exposure.
- dependant on films contrast level and relative speed.

Question 10

Faster the film speed, lower the contrast, wider the range of _____.

Answer 10

Latitude/dynamic range

Question 11

Negative effects due to a wide latitude/dynamic range

Answer 11

• contrast
• definition
• ability to see fine details