Basic principles of photography

Camera obscura- Darkroom (latin)
light passing through a small hole and produces an inverted image on the opposite wall
Receives images like the human eye
Rays from the tops are reflected from the hole
Artists, Davinci, used it
Johannes Kepler (1604)
1609-lens
Further refinements, used by the 18th-century artists
Joseph Niepce, earliest photo- used a puta plate and coated with a small amount of bitumen – several days worth of exposure
First production camera- daguerreotype  (1840s)

Pinhole cameras
Cam Obscura is an example of a pinhole camera
Problems- tiny aperture means little light gets in
big aperture means it will be blurrier (so use a lens)

Modern film tech
This is substrate coated with light sensitive chemical
modern colour film attaches dye molecules to achieve sensitivity

35mm
Each image is 36×24 mm

Using focus
moving the focal plane can cause a blurry or not image
Can change the composition dramatically by changing focal length

Exposure
Good photo= right amount of light
Two main parameters; Shutter Speed (controls how long the exposure- reduces motion if it is a fast but lets less light in) and Aperture (Diameter of lens opening, the f-number, big aperture means more light, but shallow depth of field)
f/16=1/8
f/11= 1/15
f/8=1/30
f5.6=1/60
f/4=1/125

Depth of field
small aperture- large DOF
large aperture- small DOF
When using “aperture priority” mode, the camera uses the widest aperture for the viewfinder

ISO- sensitivity
ISO 100- low sensitivity to light- good for bright conditions, static scenes, wide aperture, slow shutter
ISO 1600- High sensitivity, good for low light, dynamic scenes, small aperture, fast shutter
High sensitivity= noise/grain

Camera modes
P- camera chooses shutter speed and aperture to achieve correct exposure
S- user sets shutter speed, camera chooses aperture
A- user sets aperture, camera chooses shutter speed
M- User sets both aperture and shutter speed

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