Introduction to Photography Flashcards
What is focal length?
The distance between the lens and image sensor when the subject is in sharp focus
What is focal length measured in?
mm
What does focal length affect? (3)
Perspective
Depth of field
Field of view
What is depth of field?
How much within the image is in focus
What is field of view?
How much you can get in the picture
What does the size of the focal length indicate?
Shorter focal length = wider field of view and lower magnification
Longer focal length = narrower field of view and higher magnification
What does proper exposure mean?
Recording a full scale of tones, from detail in the dark areas through to the brightest parts of the image
How can exposure be controlled?
Through aperture and shutter speed
What are histograms?
Graphical representations of the pixels exposed in your image
What does the left side of a histogram represent?
Blacks/shadows
What does the right side of a histogram represent?
Whites/lights
What does the middle section of a histogram represent?
Mid-tones or greys
What is ISO?
Each pixel in digital photography has a fixed sensitivity to light and is measured in ISO
What happens when sensitivity of an image is increaseD?
Increased background noise, resulting in a grainy look
What is the range of ISO to be used for indoor photography?
400-800
What is the maximum ISO to be used outdoors in sunny conditions?
100
What is the aperture?
“Lens diaphragm”
Size of the opening in a camera lens
What does the aperture regulate?
The amount of light that passes through the lens and onto the sensor
What can the function of the aperture be compared to?
Function of pupil
What is aperture control expressed in?
f-stops
What does each f-stop due to the light passing through?
Changes the amount of light by a factor of two
What does a larger aperture/lower f-number allow?
More light to enter the camera
How does aperture affect DOF?
Lower f-number = more shallow depth of field
What are the appropriate f-numbers for crime scene photography?
f/8, f/11
What is considered an acceptable DOF?
1/3 in front of the subject and 2/3 behind
In what three conditions does the greatest DOF occur?
High f-number
Short focal length
Distant subject
What is a shutter?
Device that controls the length of time light is allowed to travel to the image sensor
What is B shutter speed?
Stands for ‘Bulb’
Holds the camera shutter open until the shutter trigger is released
What is the minimum shutter speed for handheld use?
1/60
At what shutter speeds must a tripod be used?
Slower than 1/60
How is minimum shutter speed related to focal length?
Minimum shutter speed reciprocal of the maximum focal length available to that lens (1/focal length = shutter speed_
What is the rule of reciprocity?
If you increase the time (shutter speed) then you must reduce the amount o light (focal length)
