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What does the Shutter do?
• Controls the amount of time light is allowed to strike the film
(compare to Aperture- which controls the amount of light allowed to strike the film)
• Controls motion• Water faucet example- trickle versus a flow (the
shutter speed determines how long the light is allowed to strike the film, just as how long the water flows determines how much water is in a glass).
Shutter Speeds
B 1 2 4 8 15 30 60 125 500 1000 2000
• B represents bulb, which refers to the use of flash bulbs with earlier camera models.
• The 1 refers to a 1 second exposure, all other numbers are a fraction of a second.
• Shutter speeds are in 1-stop increments, so a change in settings either halves or doubles the speed
Types of Shutters
Focal Plane
• Made of cloth or metal• Travels across the film plane horizontally or
vertically.• Allows a small slit of light to expose the film plane.
Leaf Shutter
• Located in the lens barrel• A function of the aperture
mechanism but is also controlled by the shutter speed
• Exposes the entire film plane as the metal leaves open
Controlling Movement
• Camera movement- results when shutter speed is too slow to hold the camera steady
• Subject movement- using a fast shutter speed to stop the action or a slow shutter speed to allow a blurring effect
Fast Shutter Speed
• Stops action• Add an element of
tension or dynamics
Slow Shutter Speed
• Showing movement in a photograph
• Blurring the action in a scene
Panning
• Allows the subject to remain in focus
• Causes the background to appear out of focus because of camera movement
• Gives the illusion of dynamic speed
APERTURE
Aperture description…• referred to as the opening inside a photographic
lens. • The size of the opening in a camera lens regulates
the amount of light that passes through onto the film (or sensor) inside the camera the moment when the shutter curtain in camera opens during an exposure process.
• Regulates the depth of field within a photo.• Aperture size is usually calibrated in f-numbers or f-stops. Each of this value represents one time the amount of light either more or less in quantity.
The smaller numbers on the left side (starting with f/2.8) let in MORE light
The largest number on the right (f/22) lets in the LEAST amount of light
CONTROLLING THE AMOUNT OF LIGHT:
Depth of Field
• Refers to the amount of the picture plane that appears to be in focus
• May be referred to as shallow, medium, or wide depth of field
The MORE light let in, the the SHALLOWER the depth of field (fewer parts of the image are in focus)
The LESS light let in, the WIDER the depth of field (more parts of the image are in focus)
CONTROLLING THE FOCUS- DEPTH OF FIELD:
At f/2.8 only the focused subject will be sharp; foreground and background won't. This effect may be very dramatic with portraits.
Many photographers prefer very sharp images. With a really wide aperture images may look soft. Using a smaller aperture will improve the sharpness of the photograph dramatically.
With smaller apertures (f11) everything in the scene will be very sharp. Many lenses have a so-called sweet spot where the lens reaches the maximum sharpness (in many cases at f/8 or f/11).
Exposure
Exposure: the total amount of light allowed to fall on the photographic medium (photographic film or image sensor) during the process of taking a photograph.
How do you determine a correct exposure?
1. Control the exposure time and amount of light by adjusting the shutter speed and aperture settings
How do you determine a correct exposure?
2. Determine the sensitivity of the film– Sensitivity of film to light is referred to as film
speed– Film speed is measured on a scale by ISO– The faster the film speed (larger the number),
the more sensitive the film is to light– The slower the film speed (smaller the number),
the less sensitive the film is to light
Fast Film speed
The high sensitivity to light with the fast film speed produces a very grainy effect on the photograph.
Slow Film Speed
The low sensitivity to light with the slow film speed produces a very detailed effect on the photograph. Little or no grains appear on the photograph.
Which film speed (fast or slow) would work best for a night-time/
low light photograph? Why?
Fast Film Speed
-best for low light/ indoor due to the fact that it is more sensitive to light
Which film speed would work best for a day-time/ good lighting
situation? Why?
Slow Film Speed
-less sensitive to light, and does not produce the grainy look that a high
film speed film would create.
How do you determine a correct exposure?
TIPS & TRICKS:“Sunny 16” Rule:
-method to estimate correct daylight exposures without using a light meter-applicable as an estimate to use on a sunny day-Set aperture to f/16 and shutter speed to ISO film speed.
How do you determine a correct exposure?
TIPS & TRICKS:“Sunny 16” Example:
-If my film speed was 400, I would set my aperture at f/16 and my shutter speed to 500 (which is the closest setting to 400)
“Sunny 16” Activity:
Looking at the cameras at the tables, what would be the correct aperture and shutter speed settings to use if you had 125 speed film and were attempting to determine the correct exposure following the “Sunny 16” rule?
Aperture Setting: f/16
Shutter Speed Setting: 125
“Sunny 16” Activity:
What would the correct aperture and shutter speed settings be if my film speed was ISO 50?
Aperture Setting: f/16
Shutter Speed Setting: 60 (which is closest to ISO 50)
The Law of Reciprocity
The shutter speed works with the aperture to provide correct exposure. This relationship is called the “law of reciprocity.”
This law states that if you change one part of the relationship, such as the f/stop, you are required to change the other part of the relationship, the shutter speed, to maintain the equivalent exposure.
The Law of Reciprocity:
Overexposure!!!Changing only the aperture setting by opening up with a correct meter reading results in overexposure- exposure to too much light. You don’t want this!
The Law of Reciprocity:Underexposure
Changing only the aperture setting by stopping down with a correct meter reading may result in underexposure- not enough exposure to light. You don’t want this!
The Law of Reciprocity is best described while looking at a chart with standard aperture and shutter speed settings:
Imagine the correct exposure (determined by your light meter) is stating that f/4 and 1/125 is the correct exposure. You have the ability to use this setting, or change aperture and shutter speeds in relation to each other to create an equivalent exposure. The key is to understand that if you add more light (open the aperture) you must speed up your shutter speed. And if you decrease your light (stop down the aperture) you must slow down your shutter speed.