This document provides definitions and basic photographic concepts: 1. Lenses are categorized as prime lenses with a fixed focal length or zoom lenses with a variable focal length. A normal lens on a 35mm camera has a focal length of 50mm. Wide-angle lenses have shorter focal lengths and telephoto lenses have longer focal lengths. 2. Film has a light-sensitive layer called the emulsion. ISO rates the film's sensitivity to light - higher ISO means faster/more sensitive film. 3. The shutter controls the duration of exposure, affecting the recording of movement. Aperture controls the amount of light through adjustable openings called f-stops, also impacting depth of field.

1. Photo 1 Foothill College
Eugene Louie
Basic Definitions
Lenses
1. Lenses can be either _________________ focal length (hint: a prime lenss) or a ____________ lens with
a variable focal length. A _____________ is defined as any lens that can be adjusted so the photograher
doesn’t have to move to make the image in the viewfinder look bigger or smaller.
A 35 - 70 zoom incorporates all the focal lengths between 35 and 70 mms inclusive. There are three
major divisions of lenses: Normal lenses: See and record an image much as your eye sees it. On a 35mm
camera, the focal length considered normal is a ____________mm.
a. 24 mm
b. 35 mm
c. 50 mm
d. 65 mm
Wide-angle lenses: Give a wider angle of view and have a greater depth of field. These are lenses with
focal lengths shorter than normal. A 24mm, 28mm, and 35mm are common wide-angle lenses for the
35mm camera format.
Telephoto lenses: Bring distant subjects into view, have a shorter depth of field, compress space and
give a narrow angle of view. Lenses with focal lengths longer than 50mm are usually classified as
telephoto lenses.
Film
A plastic base with a light sensitive layer called the ___________. The more light contacts the film, the
darker it becomes when the “latent image” is developed. Different films have different sensitivities to light.
The easiest way to remember the relationship between negative to black & white printing paper is to
remember: “Emulsion to Emultion.”
ISO is a number that tells us how sensitve a particular film is to light. A HIGH ISO MEANS IT IS A FAST
FILM.
ISO 100 ISO 400 ISO 1600
LESS SENSITVE TO LIGHT MEDIUM SPEED HIGH SPEED More Sensitive 2
light.
A SLOW FILM Tri-X or Ilford HP5 A Fast Film
Shutter
The shutter controls the length of time the film is exposed. The length of time that the shutter is kept open is
called the shutter speed. The shutter also affects the way in which movement is recorded. Slower speeds
emphasize camera and subject movement. Faster speeds quot;stopquot; camera and subject movement.
F-stop
A variable size hole or opening. Also called aperture. The aperture controls the amount of light which
reaches the film. F-stops also control depth-of-field. The smaller the f/ stop, the more depth of field.
f 2.8 f/ 4 f/5.6 f/8 f/11 f/16 f/22
Little, or minimal, Depth of Field More
Depth of Field
Big Aperture Small Aperture
ISO
Often called quot;film speedquot; is a measurement of the sensitivity of a particular film to light. The higher the ISO

2. the greater the film's sensitivity to light.
Exposure Modes
The following are the modes available to photographers to determine exposure:
Manual.................................. Photographer sets both shutter speed and aperture
Automatic ............................ Aperture priority or Shutter priority
Aperture priority................... Photographer sets aperture; camera sets shutter speed.
Shutter priority...................... Photographer sets shutter; camera sets aperture
Program................................ Camera sets both aperture & shutter speed (There are variations on this mode
such as quot;program Hiquot; for shooting sports etc.)
Middle Gray
This is the tone for which all meters are calibrated to reproduce. ANYTHING you point your camera at with
the reflected light meter built inside will become “middle gray”! This works most of the time. Can you think
of a situation where it wouldn't work?
Back Lighting
A lighting situation in which most of the light is in back of rather than directed at the subject. In such
situations, an exposure adjustment is needed (Will you need more exposure or less exposure?)
Bracketing
A way to help ensure a properly exposed negative; first take an exposure reading of a subject with your light
meter and shoot a picture at that setting, then take extra exposure of the subject at f-stops or shutter speeds
on either side of the first reading to allow either more or less exposure to reach the film. These extra
exposures can be made by altering the auto exposure compensation dial or by photographing in the manual
mode.
Understand Perspective: Definition is in chapter on lenses.
Formula to Calculate a len’s f/stop is: (for you to discover, again).
Depth of Field
Equivalent Exposure