Sensitized Material

Refers to the film and photographic paper that basically composed of emulsion containing silver halides suspended in gelatin and coated on a trasparent or reflective support

Parts of Sensitized Material

Emulsion Part of the film or photographic paper which

contains the silver grains that is sensitive to light Colored films contain 3 layers of emulsion (blue,

green, red) with intervening filters Anti-Halation Backing

Designed to hold back the light and prevents halation

Base Support the emulsion

Types of Film(According to Use)

Black and White Film Usually represented by a prefix or a suffix “pan” or

“ortho” and generally used in black and white photography

ex. ortholith, tri x-pan, pan x-plus Colored Film

Negative Type Reversal Type

Types of Films(According to Spectral Sensitivity)

Blue Sensitive Film Sensitive to UV light up to blue color

Orthochromatic Film Sensitive to UV light up to green color

Panchromatic Film Sensitive to UV light up to red color (visible light)

Infra-Red Film Sensitive to all colors and infrared light

Film Speed (Emulsion Speed)

ASA (American Standards Association) Expressed in arithmetic value system The higher the number, the more sensitive the film is ASA 10, 20, 30, 40, 50, 100, 200, 400, 800, 1000

DIN (Deutche Industre Normen) Expressed in logarithmic value system Used in the same principle as the ASA (3 degrees) DIN 12, 15, 18, 21, 24, 27 30, 33

ISO (International Standards Organization) Expressed in combination of ASA and DIN ratings

Photographic Paper

Sensitized material that will record the visible image in the final development and become the photograph

Types of Photographic Paper(According to Emulsion Used)

Silver chloride paper Used for contact printing Size of the positive print is the same as the size of

the negative used. Sensitivity to light is low and gives blue-black tones

when properly developed Silver bromide paper

Used in projection, printing and enlarging process. Most ideal paper used in police photography. Will give black tones when properly developed

Silver Chlorobromide Paper Used for both projection and contact printing Slow emulsion

Variable contract paper Combines the contrast range in one paper Uses a special chlorobromide emulsion that

produces varying contrast responses upon exposure to different colors of light

Types of Photographic Paper(According to Physical Characteristics)

Weight Light Weight

Designed for high flexibility and when paper thickness is not of consideration

Intended for purposes which involved folding Single Weight

Used for small prints or which are needed to be mounted on solid fine details necessary in the production

Used in ordinary photographic purposes Double Weight

Generally used for large prints because they stand up under rough treatment

Surface Texture Glossy Paper

Designed for fine details and brilliant image formation Semi-matte Paper

Obscure fine details Rough Paper

Used for large prints or where breath rather than detail is necessary

Color White Paper

Better used in police photography Cream Paper

Preferred for pictorial effect, portraits, landscapes or where warmth effect is desired

Buff Paper Paper for tone prints

Types of Photographic Paper(According to Contrast)

Velox No. 0 Used for printing extremely contrast negative or

expremely exposed film Velox No. 1

Used for high contrast negative or over exposed film

Velox No. 2 Used for normal exposed film

Velox No. 3 Used for negative with weak contrast or

underexposed film

Velox No. 4 Used to provide sufficient contrast to compensate for

very thin or weak negatives Useful imprinting if high contrast is desired

Velox No. 5 For flat negatives that are unprintable

Chemical Process

Process of making the latent image visible and permanent

Development The process necessary for reducing the silver halides to form

the image Use either D-76, Dektol or Universal Solution Elon Hydroquenone

Used as the main developing agent

Stop Bath Normally composed of water with a little amount dilute acetic

acid that serves as a means to prevent contamination between the developer and the acid fixer

Fixation Process by which al unexposed silver halides are dissolved or

removed from the emulsion surface and making the image more permanent

Sodium Thiosulfate (Hypo) Main fixing agent that dissolves unexposed silver halides

Other Chemicals Used

Acetic Acid and Boric Acid Serves as neutralizer

Sodium Sulfate Serves as the preservative

Potassium Bromide (ALUM) Restrainer or Hardener

Sodium Bicarbonate and Borax Powder Serves as accelerator

Dark Room Techniques

Dodging Process of eliminating unwanted portion of the

negative during enlarging Cropping

Process of omitting an object during the process of enlarging and printing

Vignetting Gradual fading of the image towards the side

through skillful adjustment on the dodging board

Dye Toning Process designed in changing the color of the

photograph

Burning-In Refers to the additional exposure on a desired

portion of the negative used for purposes of making a balanced exposure