Transcript sensitized material and developing process

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



Colored films contain 3 layers of emulsion (blue,
green, red) with intervening filters
Anti-Halation Backing


Part of the film or photographic paper which
contains the silver grains that is sensitive to light
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


Orthochromatic Film


Sensitive to UV light up to green color
Panchromatic Film


Sensitive to UV light up to blue color
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



Single Weight



Designed for high flexibility and when paper thickness is
not of consideration
Intended for purposes which involved folding
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


Semi-matte Paper


Designed for fine details and brilliant image formation
Obscure fine details
Rough Paper

Used for large prints or where breath rather than detail is
necessary

Color

White Paper


Cream Paper


Better used in police photography
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


Velox No. 1


Used for high contrast negative or over exposed
film
Velox No. 2


Used for printing extremely contrast negative or
expremely exposed film
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


Stop Bath


Used as the main developing agent
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)
Other Chemicals Used

Acetic Acid and Boric Acid


Sodium Sulfate


Serves as the preservative
Potassium Bromide (ALUM)


Serves as neutralizer
Restrainer or Hardener
Sodium Bicarbonate and Borax Powder

Serves as accelerator
Dark Room Techniques

Dodging


Cropping


Process of eliminating unwanted portion of the
negative during enlarging
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