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