Digital Photography Jamel Gantt Aperture ISO Shutter Speed
THE EXPOSURE TRIANGLE The Different Exposure – Jamel Gantt
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. Be sure to take notes when necessary.
Exposure Exposure is the total amount of light that you allow into the camera
Exposure Triangle ISO
Changing any of the three elements will effect the exposure
Aperture
Shutter Speed
Aperture and shutter speed are inversely proportional to each other.
Exposure Triangle
http://www.flickr.com/photos/robert_d_ellis/5387408926/
Camera Configuration
Digital Sensor Shutter Aperture Lens
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.
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Exposure Too little light results in an under-exposed image where there are areas of low detail.
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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
Shutter Speed
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
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
Shutter Speed Action shots require fast shutter speeds.
Callaway Gardens Steeple Chase 14
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.
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Low Light requires longer shutter speeds and a tripod
Full 1 second shutter speed Langdale Mill
Low Light requires longer shutter speeds and a tripod
Shutter Speed
Must use A tripod
Best for Sports shots
ISO
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
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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
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ISO
ISO is the measurement of the sensitivity of the camera image sensor to light. An ISO of around 200 is average. 22
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
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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
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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
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
Higher ISO 400 ISO
800 ISO
Light is limited and flash was not desirable in either shot.
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 ISO 200
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High ISO Â This photo taken with ISO 800. Notice the grainy appearance. This is called noise.
Rome by night 29
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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.
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Aperture
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.
Aperture f-stops
Described as the f/stop the smaller the number the wider the lens will open
Stopping down
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.
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
F/stops and depth of field Lower f stops need less light to expose
f/2
Depth of Field decreases
Higher f stops need more light to expose
f/8
Depth of Field increases
F /22
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 Shorter shutter speed Narrow depth of field
Slow lens Longer shutter speed Large depth of field
Narrower Depth of Field
More exposed
Longer Shutter Speeds
Greater Depth of field
Aperture
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Shutter Aperture Relationship The smaller the aperture, the longer the shutter speed The larger the aperture, the shorter the shutter speed.
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.
Sunny Sixteen Rule
Aperture Stops Aperture stops conditions Conditions snow or beach f/22 -1 stop f/16
sunny-16
bright daylight dark shadows
f/11
+1 stop
weak or hazy sun sun low in sky
f/8
+2 stops
cloudy bright
f/5.6
+3 stops
darker clouds subject in shadow
f/4
+4 stops
sunset
Issues with each exposure point ISO Noise
Changing any of the three elements will effect the exposure
Aperture
Shutter Speed
Motion Blur Depth of Field Aperture and shutter speed are inversely proportional to each other.
Manual Settings Dial
Creative Camera Modes
Point and Shoot Modes
Creative modes
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
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.
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.
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.
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.
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
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)
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.