PH1000-T&P Flashcards
camera
A light-tight container used for taking photographs by letting light from an image fall onto sensitized film, usually by means of a lens and a shutter mechanism.
types of cameras
point-and-shoot
instant
digital camera
single-lens-reflex (SLR)
twin-lens-reflex (TLR)
rangefinder
view camera
plastic “toy” camera
pinhole
SLR
single-lens-reflex
This camera has one lens through which the picture is seen, focused, and taken. The viewing system includes a mirror located between the film and the lens. The mirror swings up when the shutter opens and allows the film to be exposed.
digital camera
This camera is an electronic device used to capture and store photographs with an electronic sensor instead of using photographic film to capture light. Light from the subject passes through the lens and falls onto the sensor; the pattern of light recorded by the sensor is stored as a digital file of the image, either in the camera or on a removable memory card. The digital image files can then be downloaded to a computer or to a portable hard drive.
film format
Refers to the size of film used by a particular camera. Types of film formats:
35 mm
Medium format (2 3/8” wide)
Large format (film in single sheets)
film
B&W film consists of a clear, flexible, plastic support, called the BASE, coated with a microscopically thin emulsion. The EMULSION is a compound of light-sensitive SILVER HALIDE CRYSTALS suspended in GELATIN. It is coated with a PROTECTIVE LAYER to minimize scratching and backed by an ANTIHALATION LAYER that helps promote image sharpness.
ANTIHALATION is the process of treating a film base with a light-absorbing substance to prevent refraction of light from the rear of the film.
film characteristics
film speed
grain
tone
contrast
film speed
FILM SPEED RATING is a measurement of how sensitive a film is to light. Through extensive testing it is determined by the ASA (American Standards Association) or ISO (International Standards Organization) exactly how much light is needed to register a change in the film.
ISO and film characteristics
The lower the ISO, the smaller the silver crystals, the slower the film, the less sensitive to light: therefore more light is needed to expose it properly.
The higher the ISO, the larger the silver crystals, the faster the film, the more sensitive to light; therefore, less light is needed to expose it properly.
grain
When film is developed, the silver halide crystals that were exposed to light form small black clumps of metallic silver called GRAIN that make up the photographic image. The size of the individual clumps can vary according to the type of film you use.
In addition to film type, other factors that determine grain include: film exposure, film development, film format, and print size.
tone
The range of shades (blacks, grays, and whites) that make up a B&W photograph are called TONES, and the variety of tones from dark to light in an image is called the TONAL RANGE.
Some films are capable of reproducing more of a subject’s tones than others. The fine grain of a slower speed film captures more information, often times reproducing more tones than faster films.
Several other factors play a role in tonal range, including: the inherent tonal characteristics of the subject, film format, and film exposure and development.
contrast
CONTRAST refers to the relative difference between light and dark tones in the original subject, in the negative, and in the print that represents the subject.
Some films produce more contrast than others. High-contrast films produce dense blacks and bright whites with few shades of gray.
Contrast is a function of several factors other than the film you use. The original subject lighting is critical, as is film exposure and develoment. When printing, you can use different papers and/or filters to vary the image contrast.
camera lens
The camera lens is located on the front of the camera body with the film positioned directly behind it. When the shutter opens, light travels through the lens and exposes the film.
The lens controls four functions:
image focus (distance between camera and where focusing)
film exposure (quantity of light)
angle of view (wide, standard, telephoto)
depth of field
focal length
FOCAL LENGTH is a measurement of the lens size, the distance between the film plane of the camera and the optical center of the lens when the lens is focused to infinity.
(2) The distance from the lens to the focal plane when the lens is focused on infinity. The longer the focal length, the greater the magnification of the image.
focal length of a standard lens
is approximately equal to the length of the diagonal of that format’s negative size. For a 35mm camera, the diagonal of the negative size measures about 50mm, so a lens with a focal length of 50mm is considered standard.
For medium format film, a standard lens is between 70 and 90mm, depending on whether the exposure is square or rectangle.
