19/11/2024
At the end of this topic, students should
be able to :
PHOTOCHEMISTRY Define superadditivity and selectivity.
State pH scale and pH value for developer and fixer.
Discuss solution constituents and its fuctions.
List factors affecting development and fixation
Image Processing and Quality
Assurance I
Describe starter and replenishment solution.
Explain importance of washing and drying.
1 2
Concept of pH
pH – Quantitative method of measuring the degree
of acidity or alkalinity of a solution.
pH ranges from 1 – 14
pH SCALE OF DEVELOPER AND FIXER
1------------------------- - - - - - 7 ----------------------- 14
(decreasing acidity) NEUTRAL (increasing alkalinity)
Developer Fixer
A solution of :
pH range : 9.6 – 10.6 pH range : 4.2 - 4.9
pH 7 is NEUTRAL ±0.2 ±0.2
pH > 7 is ALKALINE
pH < 7 is ACIDIC
3 4
, 19/11/2024
Development
Exposed Crystal Unexposed Crystal
1. DEVELOPING Latent
Formation of the image (latent to visible image). image
centre
2. FIXING Changes of silver bromide crystal
4 STEPS OF Stopping of development,
permanent fixing of image on film. containing the latent image to metallic
PROCESSING 3. WASHING
Removal of residual fixer.
silver that constitutesmembentuk the
visible image.
4. DRYING
Warm air blowing over film.
5 6
Fixing Washing
Involves 2 activities:
Removal of the soluble fixing bath
I. Removing the unexposed and
and silver salts from emulsion by
undeveloped silver bromide.
clean, flowing water.
II. Hardening the soft gelatin emulsion.
7 8
At the end of this topic, students should
be able to :
PHOTOCHEMISTRY Define superadditivity and selectivity.
State pH scale and pH value for developer and fixer.
Discuss solution constituents and its fuctions.
List factors affecting development and fixation
Image Processing and Quality
Assurance I
Describe starter and replenishment solution.
Explain importance of washing and drying.
1 2
Concept of pH
pH – Quantitative method of measuring the degree
of acidity or alkalinity of a solution.
pH ranges from 1 – 14
pH SCALE OF DEVELOPER AND FIXER
1------------------------- - - - - - 7 ----------------------- 14
(decreasing acidity) NEUTRAL (increasing alkalinity)
Developer Fixer
A solution of :
pH range : 9.6 – 10.6 pH range : 4.2 - 4.9
pH 7 is NEUTRAL ±0.2 ±0.2
pH > 7 is ALKALINE
pH < 7 is ACIDIC
3 4
, 19/11/2024
Development
Exposed Crystal Unexposed Crystal
1. DEVELOPING Latent
Formation of the image (latent to visible image). image
centre
2. FIXING Changes of silver bromide crystal
4 STEPS OF Stopping of development,
permanent fixing of image on film. containing the latent image to metallic
PROCESSING 3. WASHING
Removal of residual fixer.
silver that constitutesmembentuk the
visible image.
4. DRYING
Warm air blowing over film.
5 6
Fixing Washing
Involves 2 activities:
Removal of the soluble fixing bath
I. Removing the unexposed and
and silver salts from emulsion by
undeveloped silver bromide.
clean, flowing water.
II. Hardening the soft gelatin emulsion.
7 8
