A Photo Teacher |

The Camera and the Lens

Posted in Lecture Materials by Paul Turounet on February 1, 2010

Getting Started

Loading Film

Holding the Camera


Types of Cameras

Phone camera (left) | Point and Shoot camera – film and digital (center) | Digital Point and Shoot camera with interchangeable lenses (right)


Single-Lens Reflex (SLR) – 35mm film (left) | Digital Single-Lens Reflex (middle) | Medium-format Single-Lens Reflex – 120 film (right)

  • Offer greatest variety of interchangeable lenses
  • Film/sensor records what is seen in viewfinder


Rangefinder – 35mm film and digital (left) | Medium-format Rangefinder (120 film) | Twin-Lens Reflex – 120 film (right)

  • Compact and quiet
  • Bright viewfinder for ease of focusing / exposure flexibility

  • Parallax – difference between what viewfinder sees and what lens records


Large-Format Rail Camera (left) | Large-Format Field Camera (middle) | Large-Format Press Camera (right)

  • Direct, through-the-lens viewing system
  • Large image on a viewing screen
  • Excellent sharpness/descriptive qualities
  • Individual negatives
  • Camera bulky with expensive operating costs


Image Capture Sizes

35mm film (top left) and 24mm x 36mm full-frame sensor (bottom left) | 120 film – 6 x 6, 6 x 7 and 6 x 9 cm (middle) | 4″ x 5″ and 8″ x 10″ film


Basic Camera Controls



The Shutter

Mechanism that opens and closes for a measured length of time to admit light that passes through camera to the film plane


Types and Differences

Focal-Plane – built into camera body, overlapping curtains, less expensive, limited shutter sync speeds

Leaf – built into lens, can use flash at any shutter speed


Shutter Speed Scale

B, 1/1, 1/2, 1/4, 1/8, 1/15, 1/30, 1/60, 1/125, 1/250, 1/500, 1/1000, 1/2000, 1/4000

B is for as long as the shutter is released


© Danny Lyon, from the series The Bikeriders, 1968



Follow the motion of a moving object with the camera, causing object to look sharp and background blurred


The Aperture

Mechanism that controls the amount of light (brightness) and quality of light (depth of field) that passes through the camera to the film plane

Size of an Aperture is indicated by its f-number or f-stop


Aperture Scale

f/1.4,  f/2,  f/2.8,  f/4,  f/5.6,  f/8,  f/11,  f/16,  f/22,  f/32,  f/45,  f/64

Aperture scale for 35mm tends to run from f/1.4 – f/22, while larger formats will have a range of f/5.6 – f/64

Large Aperture –more light passes through lens, but less depth of field achieved, i.e. f/1.4

Small Aperture – less light passes through lens, but more depth of field achieved, i.e. f/16

Open Up – increases size of lens opening; to allow more light to reach film plane

Stop Down – decrease size of lens opening: to allow less light to reach film plane


Depth of Field

The area between the nearest and farthest points from the camera that is acceptably sharp in an image.



The Lens

A lens refracts light rays to be sharpened as they pass through an opening to create a sharp image on a film | sensor plane.  The lens is made up of separate lenses, usually six to eight, and is called a compound lens.  Each lens is added to correct for aberrations or focusing defects in the other.


Focal Length

The focal length of every lens is the distance, measured in mm, from the lens to the film | sensor plane when lens is focused at infinity.  Focal length controls magnification, the size of the image formed by the lens as well as angle of view.


Focus and Depth of Field

There is a plane of critical focus where the image is at its sharpest, and then the circles of confusion begin to decrease in sharpness with objects as the planes of the image move toward both the foreground and background.

Sharpness and Depth of Field

  • Smaller the aperture, the greater the depth of field
  • Shorter the focal length lens, the greater the depth of field
  • Greater the distance from the subject matter, the greater the depth of field


Zone Focusing

Using a lens’s depth of field scale to find the f-stop settings that will give adequate depth of field without having to focus the lens


Focusing on the Hyperfocal Distance

Distance to the plane of sharpest focus when infinity is set at the farthest point on the depth of field scale, providing for maximum depth of field at that given aperture



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