Week 3

Exposure
total amount of light used to create an image
controlled by shutter speed and lens aperture
1/125sec at f2.8 same amount of exposure as
1000,500,250,125,69,30,15,8,4,2,1 shutter speed (length of exposure)
1,1.4,2, 2.8,4,5.6,8,11,16,22,32 f-number (intensity of exposure)
ISO rating
Subject lighting (level of reflectance)
Your preference
ISO rating
Film with high sensitivity to light has a high rating
Higher the number= greater the light
Film with low sensitivity to light has a lower rating
DIN (Deutches Institut Fur Normung)
ASA (American Standards Association)
ISO (International Standards Organisation)
Eg: Liford HP5> DIN27>ASA 400
Kodak Tmax100> DIN21>ASA 100
Agfrapan25> DIN15>ASA 25
1987: adoption of ISO as standard which uses ASA scale
ISO Standard
A double of the rating= doubling of sensitivity
Eg: ISO400 film is twice as sensitive to light as ISO200 film
Therefore: ISO400 film requires half the exposure as ISO200 film to produce a specific exposure
Assume: ISO200 requires 125 @ f8
Then: ISO400 requires 250 @ f8

Week 2

Aperture
Means hole or opening
Different sized apertures allow exposure to be varied
“Waterhouse stop” – John Waterhouse 1855
Iris diaphragm allows infinitely more control
Term “stop” is still used to refer to a particular setting
Shutter
Mechanism to begin and end exposure/capture
Early versions were simply a lens cap
Low light level requires a long exposure
High light level requires a short exposure
Focal plane or between the lens (BTL/Leaf) variety
Shutter types
Focal point operates in front of the film at the focal plane
BTL/Leaf operates inside the lens much like a diaphragm
Focal plane shutter
2 rubberished cloth curtains, one opens to start the exposure and the second closes to end the exposure
Today, metal blades
Diaphragm, aperture, f-stop, f-number
Diaphragm= mechanism
Aperture= hole/opening
f-stop= particular sized opening
ie; an f-number of 16 is written as f-16 or just f16
f-number=number representing opening
large f-number= small hole= less light passed
small f-number= large aperture= more light passed
typical range of standard f-number
1, 1.4,2, 2.8,4,5.6,8,11,16,22,32
Multiplied by .4
Shutter, shutter release, shutter speed
Shuter=mechanism
Shutter release=the “magic” button
Shutter speed= length of time shutter is open
1/6 sec=60
Large number= short time= less light
Small number= long time= more light
Small number=long time=more light
Typical range of standard shutter speed
1,2,4,8,15,30,60,125,250,500,1000,2000
Each step either double or halves amount
Exposure
Total amount of light captured
Eg: high exposure, low exposure
Exposure= time x intensity
Time= shutter speed
Intensity= aperture size
Shutter speed range
Lens aperture ramge
Exposure range
Exposure modes
ISO range
Preset white/ grey balance
File type

Week 1

Introduction
Camera- (Latin), vault, vaulted room/ small boat
Obscura- (latin), darkness
Camera obscura used as a drawing aid
1265- roger bacon (English philosopher) write about the camera obscura from 10th century arab scholars writings
1490- Leonardo da viinci describes one in detail
1558- Giovanni Battista Della Porta, suggests its use as a drawing aid and then went on to install a mirror and lens to reinvert the image and to make it sharper and brighter
1557- first moveable camera obscura appeared
1685- telephoto lens
Light sensitive materials
There were many significant discoveries from early 1700’s to early 1800’s but history records Joseph Neipce as the person responsible for the first permanent camera image, a view from his window in 1826.
8 hour exposure
Bitumen of Judea on pewter
Camera basics
Light-tight body
Lens of focus the image
Means of capturing the image (film/sensor)
Aperture through which the light passes
Shutter to begin and end the exposure/capture.