“There are 4 factors that can be manipulated by the photographer that when balanced achieve the correct exposure. The combination of these factors will impact the way an image will look. Photographers make choices about each factor to create purposeful effects.”
1. Depth of Field2. Aperture3. Shutter Speed4. ISO
DEPTH OF FIELD
• Depth of Field is the range of sharpness in a picture.
• Shallow DOF is when the focal range is small.
• Deep DOF is when the focal range is large; most of the photograph is in focus.
What is the range of the depth of field? In other words, does the photo have a deep DOF, or a shallow DOF?
APERTURE• Aperture is the opening that
allows light to reach the digital camera sensor.
• Aperture is measured in f-stops. • If the f-stop number is high, the
aperture hole will be smaller, so less light will reach the sensor. This will create a deep depth of field.
• If the f-stop number is small, the aperture will widen to let more light in. This will create a shallow depth of field.
What is different about the two small figures in the background?
What do you notice about the lighting as the f-stop changes?
SHUTTER SPEED• Shutter speed is the amount
of time that the shutter is open.
• Measured in seconds• Slow shutter speeds (1/60
and slower) can be sued to achieve a blurred effect. Usually a tripod is needed.
• If you want to freeze an object in motion, a fast shutter speed is needed (fraction with a larger denominator.)
Do these photographs have a fast shutter speed or a slow shutter speed?
• Film photography: ISO is how sensitive the film is to light
• Digital Photography: ISO is a measure of the image sensitivity
• The lower the ISO number, the finer the photo will be.
• The higher the ISO number, the noisier the photo will be.
• Noise is film grain and affects the sharpness of the photo.
Is there one way to achieve correct exposure?
• No, correct exposure can be achieved by changing the: