3. Exposure
This is by far the most technical lesson of this session.
However it is essential to begin to get a grasp of the
exposure triangle concept.
You must refer to your personal camera manual in order
to completely understand how to use the creative modes.
Refer to the handout and take notes when necessary.
5. Exposure Triangle
ISO
Changing any of the
three elements will
effect the exposure
Shutter
Aperture Speed
Aperture and shutter speed are inversely proportional to each other.
8. Exposure
Too much light results in an over-exposed image
where there are areas of bright white or
’blow-outs’. These areas contain no detail or color.
8
10. Exposure
Great differences in light within a photograph
confuses the camera.
The camera exposes to the bright light , therefore
the darker portions of the photograph
are blacked out.
Vatican, Rome
12. Shutter Speed
Posing for 19th century photographs
Usually took as much a 5 minutes of
Sitting perfectly still.
Luckily, today we can control
Shutter speeds.
Opelika, AL
13. Shutter Speed
• Shutter Speed—the amount of time the shutter is open—
which determines how much light is captured in the
recording process
– Measured in seconds: super fast 1/2000 second to 30
seconds
– The slower the speed, the longer light can enter the
camera. Appropriate for shooting pictures in darker
situations; also great for freezing action and movement
Shutter speeds and aperture (f-stops) are inversely proportional.
13
15. Shutter Speed
Shutter speed is measure in fractions of a second.
A shutter speed greater than 1/60th second requires the use
of a stabilizing device like a tripod. Without stabilization,
the photograph will not be crisp and clear.
15
16. Low Light
requires longer shutter speeds and a tripod
Full 1 second shutter speed
Langdale Mill
20. ISO
• ISO is the measurement of how sensitive the
image sensor in the camera is to light.
– Measured in numbers 100, 200, 400, 800, etc.
– Use a lower number when smooth crisp images
are need and you have plenty of light.
– Higher numbers are used when light is limited,
you do not want to use a flash, or the subject is
moving; may result in grainy images
20
21. The Exposure Triangle
ISO – International Organization of Standardization
ISO—the measurement of the sensitivity of the camera
image sensor to light.
Measured in numbers 100, 200, 400, 800, etc.
– Lower numbers used when smooth crisp images are
desired and you have plenty of light.
– Higher numbers are used when light is limited, you do not
want to use a flash, or the subject is moving; may result in
grainy images 21
22. ISO
ISO is the measurement of the sensitivity
of the camera image sensor to light.
An ISO of around 200 is average.
22
23. ISO
An ISO of around 200 is average.
Lower numbers are used when smooth crisp
images are needed and you have plenty of
light.
Below 200
23
24. ISO
An ISO of around 200 is average.
Lower numbers are used when smooth crisp
images are needed and you have plenty of
light.
Below 200
24
25. ISO
Higher numbers are used in
• limited light conditions,
• Flash is not desirable
• subject is moving
• May result in grainy images
400 and above
25
26. Choosing ISO Setting
100 to 200 -------Outside Bright Sun
400----Shade or overcast conditions
400----Bright light indoors
800-1400----Stormy day
800-1400 – Low light indoors
27. Higher ISO
400 ISO 800 ISO
Light is limited and flash was not desirable in either shot.
28. ISO
Too little light can leave parts of your image too dark to
make out details.
If the ISO had been higher this photograph would have
been brighter.
Trevi Fountain, Rome
28
ISO 200
29. High ISO
This photo taken with
ISO 800. Notice the grainy
appearance. This is called
noise.
Rome by night
29
30. ISO 160
Notice the camera
exposes to the light
not the bride.
More advanced cameras have a
mechanism that will allow you to
expose to individual areas with in
the shot. 30
32. Aperture
f-stops
Aperture is the camera feature that regulates the amount of light
that passes through the lens by controlling the size of the opening
in the lens.
It is measured in f/stops.
33. Aperture
f-stops
Aperture is the camera feature that regulates the amount of light
that passes through the lens by controlling the size of the opening
in the lens.
Described as the f/stop
the smaller the number
Stopping down
the wider the lens will open
34. Aperture
f-stops
The common range for f-stops goes from
f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16, f/22
Narrow depth of field
f/8 is a good average aperture where
Most everything will be in focus.
Infinite depth of field
35. F/stops and depth of field
Lower f stops need less light to expose Higher f stops need more light to expose
Depth of Field Depth of Field
decreases increases
f/2 f/8 F /22
36. Aperture
f-stops
Full f-stops go from
f/1.4, f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16, f/22, f/32
Each full stop value increase, decreases the light entering the camera
by half.
Fast lens Slow lens
Shorter shutter speed Longer shutter speed
Large depth of field
Narrow depth of field
37. Greater Depth of field
Longer Shutter Speeds
Aperture
More exposed
Narrower Depth of Field
37
38. Shutter Aperture Relationship
The smaller the aperture, the
longer the shutter speed
The larger the aperture, the
shorter the shutter speed.
39. Sunny Sixteen Rule
The "rule of sunny-16" is simply a handy trick to remember
away to set proper exposure when the sun is high in the sky
And casts strong shadow on a bright day.
The camera aperture is set to f/16
(hence the -16 in sunny-16). dark shadows.
The sunny sixteen rule
was NOT used in this
photoghraph.
40. Sunny Sixteen Rule
Aperture
Aperture Stops
stops Conditions
conditions
f/22 -1 stop snow or beach
bright daylight
f/16 sunny-16 dark shadows
weak or hazy sun
f/11 +1 stop sun low in sky
f/8 +2 stops cloudy bright
darker clouds
f/5.6 +3 stops subject in shadow
f/4 +4 stops sunset
41. Issues with each exposure point
ISO
Noise
Changing any of the
three elements will
effect the exposure
Shutter
Aperture Speed
Depth of Field Motion Blur
Aperture and shutter speed are inversely proportional to each other.
44. Program Mode
P
Shutterspeed (exposure) and Aperture are set in unison automatically.
When you change the shutter speed, the aperture changes automatically
When you change the aperture, the shutter speed changes automatically
45. Aperture Priority Mode
Av
Use Av when :
Want everything
In focus (use high f/stop)
OR
Want the background to be out of
Focus (use low f/stop)
In AV mode, the aperture remains constant.
By turning the main dial on your camera, you can adjust the
shutter speed.
The aperture remains the same.
46. Shutter Priority Mode
Tv Action shot mode
In Tv mode, the shutter speed
remains constant.
By turning the main dial on your
camera, you can adjust the
aperture.
The shutter speed remains the
same.
47. Manual exposure mode
In M mode, the aperture and the shutter
speed can be altered.
By turning the main dial on your camera, you
can adjust the shutter speed.
The aperture remains the same.
Read your camera manual to determin how to set boththe Av and the Tv
In the Canon Rebel
Set the Tv by turning the dial
Set the Av by holding down the Av button and turning the dial.
48. Manual exposure mode
In the Canon Rebel
Set the Tv by turning the dial
Set the Av by holding down the Av button while turning the dial.
49. Manual exposure mode
In the Canon Rebel
Set the Tv by turning the dial
Set the Av by holding down the Av button while turning the dial.
The standard exposure
level is achieved when
the slide bar is located
in the center.
This meter may be viewed
on the LCD screen or
through the view finder
50. AE Lock
Consult your camera manual for AE lock steps
Exposed to the light (normal ) Exposed to a chosen darker subject
in the photo ( AE lock)
51. Automatic Depth of Field
Canon's auto depth of field (A-DEP) feature works
by (1) finding the nearest and furthest of all the
autofocus points, (2) setting the camera's focusing
distance to optimally position the depth of field
between these nearest and furthest points, and
(3) setting the aperture so that the edges of the
depth of field extend far enough to contain
these nearest and furthest points.
Editor's Notes
Refer to this handout throughout this presentation
