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