8 Flashcards
— refers to the PRINCIPLE IN PHOTOGRAPHY that explains how the latent image in the exposed film is converted into a negative image (visible image).
FILM DEVELOPMENT
Stages of Film Development: (PDSFW)
- PRE DEVELOPMENT WATER RINSE
- DEVELOPING
- STOP BATH - RINSE BATH
4.FIXING BATH OR FIXING - WASHING
This is done by simply SOAKING THE FILM IN WATER FOR 2 TO 3 MINUTES while agitating the water container for every 20 seconds.
PRE DEVELOPMENT WATER RINSE
Converting the EXPOSED IMAGE ON THE FILM INTO AN ACTUAL IMAGE. Exposed film affects the silver halides, but the change is invisible. It ENABLES THE INVISIBLE IMAGES TO FORM. This is performed by SOAKING THE FILM IN THE DEVELOPER.
DEVELOPING
The REMOVAL OF THE TRACES of the developer as well as it helps in the REMOVAL OF EXCESS OR UNDEVELOPED SILVER HALIDES. This process stops development by NEUTRALIZING THE EFFECTS OF THE DEVELOPER.
STOP BATH OR RINSE BATH
It is required to loosen the silver halides from the unexposed halides so they can be washed away. This stage also REMOVES THE UNEXPOSED AND UNDEVELOPED HALIDES by converting them to SOLUBLE SALTS which may be washed from the emulsion. It also MAKES THE IMAGE PERMANENT IN WHITE LIGHT.
FIXING BATH OR FIXING
This is the FINAL PART OF THE PROCESSING CYCLE, which REMOVES THE RESIDUAL CHEMICALS SOLUBLE SILVER COMPOUNDS from the emulsion and reveals the image.
WASHING
Chemical Contents of Developing: (RARP)
- REDUCER: METOL, HYDROQUINONE
- ACCELERATOR: BORAX, SODIUM CARBONATE, SODIUM HYDROXIDE
- RESTRAINER: POTASSIUM BROMIDE
- PRESERVATIVE: SODIUM SULFITE, SODIUM BISULFATE
The Three Forms Of Rinse Bath Are:
- WATER RINSE BATH
- ACID RINSE BATH
- HARDENING RINSE BATH
Ingredients of Fixing Bath:
- FIXER: hypo (sodium thiosulfate)
- NEUTRALIZER: acid (acetic acid)
- PRESERVATIVE: sodium sulfite
- HARDENER: potassium alum
The MOST IMPORTANT CHEMICAL IN ANY DEVELOPING AGENT. It is the one that REDUCES THE EXPOSED HALIDES into visible metallic silver. The two chemicals mostly used are: (1) __________ and (2) _________
REDUCING AGENT
- HYDROQUINONE
- METOL
energize the reducing agents and THEY SOFTEN AND SWELL THE EMULSION to permit the developer to penetrate deeply and quickly.
ACCELERATOR
Three Kinds of Accelerators:
- SODIUM CARBONATE
- SODIUM HYDROXIDE
- BORAX
It PREVENTS STAIN and MAKES the developing SOLUTION MORE STABLE AND LONG-LASTING.
PRESERVATIVE
The commonly used preservative is __________
SODIUM SULFITE
This chemical RESTRAINS THE ACTION OF THE EXPOSED AREAS OF THE FILM and permits control of density and contrast.
RESTRAINER
__________ is the agent generally used for this purpose of Restrainer
POTASSIUM BROMIDE
Types of Developers:
- TYPE A (D-72)
- TYPE B (D-19)
A DEVELOPER FOR PRINTS. It PRODUCES A VERY HIGH CONTRAST FILM.
TYPE A (D-72)
It is SUITABLE FOR DEVELOPING FILM EXPOSED UNDER DULL OR HAZY LIGHTING CONDITIONS.
TYPE B (D-19)
This refers to the REMOVAL OF THE UNEXPOSED HALIDES which has the effect of making the developed image permanent. It is accomplished by TREATING THE FILM IN A CHEMICAL that makes the unexposed halides soluble in water so they may be washed out of the emulsion.
FIXING CHEMICALS
This refers to FIXING CHEMICAL COMMONLY CALLED “HYPO”; it is one which dissolves the unexposed silver halides.
SODIUM THIOSULFATE
This refers to fixing chemicals that is USED TO NEUTRALIZE THE DEVELOPER. When a negative is removed from the developer, the emulsion is saturated with the solution.
ACETIC ACID (28%)
This refers to fixing chemical that is ADDED TO ACETIC ACID TO NEUTRALIZE THE DEVELOPER but CAUSES THE HYPO TO BREAK DOWN, liberating sulfur. It is a preservative just because it combines with sulfur to form new hypo.
SODIUM SULFATE
