Chapter 4

THE CAMERA

Camera Body: light tight enclosure protecting the film from unwanted exposure to light. Opens to allow loading of film.

Lens: forms and image of the subject matter on the film.

Focusing Device: moves the lens in and out to select the subject distance that will be in focus.

Viewfinder: shows the approximate view of the part of the subject that will be in the image on the film and may include a method for checking the focus of the image.

Aperture: an opening adjusting by means of a dial, lever or ring with marked f-stop numbers. Controls the amount of exposure on the film.

Shutter: shields the film from the image until the shutter release is pressed, when it opens for a measured amount of time. Controlled by a knob, lever or ring. Controls the exposure on the film.

Film Advance: a lever or knob that moves the film forward for the next photograph.

FORMAT SIZE

• an important influence on the technical quality of the image
• the rendition of detail and fineness of grain generally increase with increasing format size

Miniature Format: usually use disc film or 110 film. Is used when extreme enlargement isn't necessary.

Small Format: normally use 35mm and produce a 24x36mm image.

Medium Format: use 120 or 220 film and produce several different sizes of image depending on model of camera. 6x4.5cm, 6x6cm, 6x7cm, 6x8cm, and 6x9cm. Is useful when larger image size is desired.

Large Format: produce 4x5in, 5x7in, and 8x10in.

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Viewfinder/Rangefinder Cameras

• viewing is done through and eyepiece with its own simple lens
• advantages: lighter in weight, quieter operation, less vibration, brighter view
• since the viewfinder is not in the same position as the lens, it shows a slightly different view of the object, called paralax error

Single Lens Reflex Camera

• in an SLR the image is deflected to a ground glass by a mirror, which swings out of the way when the shutter release is pressed
• the image on the ground glass is reversed right to left, since it is a mirror image
• many SLRs use a pentaprism, located above the ground glass and show a correctly oriented image through an eyepiece
• advantage: view of actual image that will fall on the film
• focus can be seen in the eyepiece
• interchangeable lenses are possible
• generally available in 35mm and medium format

Twin Lens Reflex Camera

• two identical lenses are mounted on the camera
• one forms the image on the film (bottom lens) and the other is deflected by a mirror (top lens) to a ground glass for viewing and is reversed left to right
• because of the small distance between the lenses TLRs are subject to paralax error

View Camera

• a direct viewing system
• ground glass is placed in the exact position that the film will occupy
• the film, enclosed in a special holder is placed into the back of the camera when taking a picture
• the image seen on the back of the camera is upside-down just as the image on the film will be
• the lens and the back of the camera can be tilted and swing to alter the plane of focus or shape of the subject
• focus is checked by placing a magnifying glass on the ground glass

Lens Conversion for Medium Format

• 80mm on medium format camera is similar to 50mm on a 35mm camera
• 50mm on medium format camera is similar to 28-30mm on a 35mm camera
• 150mm on medium format camera is similar to 90mm on a 35mm camera