Post on 22-Jan-2018
transcript
Exposure Basics:Learn to Correctly Expose Your Photographs
Presented by Don Hazelwood
Sunday, March 1, 2009
What is Exposure?
Exposure is the amount of light collected by the sensor or film in your
camera during a single picture.
photograph by Jonathan Assink - Attribution-No Derivative Works 2.0 Generic
Sunday, March 1, 2009
What is Exposure?
Understanding how to correctly manipulate your
camera to achieve the exposure you desire is the key to taking good photos
every time.
Sunday, March 1, 2009
How do we control the exposure?
Exposure is nothing more then the aperture
and shutter speed working together within
the ‘confines’ of a predetermined ‘ISO’.
Sunday, March 1, 2009
(Aperture + Shutter Speed)^ISO = Exposure
Sunday, March 1, 2009
(Aperture + Shutter Speed)^ISO = Exposure
opening in the lens through which light is admitted
designated by f
the smaller the number the larger the opening & vice versa
dependent upon the lens
Sunday, March 1, 2009
(Aperture + Shutter Speed)^ISO = Exposure
depth of field is the portion of a scene that appears sharp in the image.
a smaller opening, f/16 will produce a longer depth of field
a larger opening, f/1.4 will produce a very narrow depth of field
Sunday, March 1, 2009
(Aperture + Shutter Speed)^ISO = Exposure
the amount of time the sensor or film is exposed to light
designated in seconds or fractions thereof
dependent upon the camera body
Sunday, March 1, 2009
(Aperture + Shutter Speed)^ISO = Exposure
a faster shutter speed lets in less light and can “freeze” objects in motion
a slower shutter speed will allow more light to enter and can also capture a sense of motion
the bulb setting, noted as B, allows the shutter to stay open as long as the shutter button is depressed
Sunday, March 1, 2009
(Aperture + Shutter Speed)^ISO = Exposure
also known as film speed
is the measure of the sensor or film's sensitivity to light.
lower sensitivity (lower ISO speed) requires a longer exposure and is thus called a slow film
higher sensitivity (higher ISO speed) can shoot the same scene with a shorter exposure and is called a fast film.
Sunday, March 1, 2009
(Aperture + Shutter Speed)^ISO = Exposure
the higher rated the film/sensor the grainer/noisy the image will be & less detail will be captured
film uses larger silver halide crystals
digital sensors have to increase the signal gain
Sunday, March 1, 2009
(Aperture + Shutter Speed)^ISO = Exposure
Now for photographical math2
Sunday, March 1, 2009
(Aperture + Shutter Speed)^ISO = Exposure
Aperture is measured in f/stops as indicated in the series below:
1, 1.4, 2, 2.8, 4, 5.6, 8, 11, 16, 22, 32, 45
1 being the largest opening45 being the smallest
each step to the right - HALF as much light allowed in
Sunday, March 1, 2009
(Aperture + Shutter Speed)^ISO = Exposure
Shutter Speed indicates how long the camera shutter remains open to let light onto the film or sensor.
These usually aren't noted on your camera as fractions to save space, however they represent fractions of a second.
B, 15, 8, 4, 2, 1, 1/2, 1/4, 1/8, 1/15, 1/30, 1/60, 1/125, 1/250, 1/500, 1/1000, 1/2000, 1/4000, 1/8000
each step to the right - HALF as much light allowed in
Sunday, March 1, 2009
(Aperture + Shutter Speed)^ISO = Exposure
ISO or Film Speed is noted as follows:
25, 50, 100, 200, 400, 800, 1600, 3200
each step to the right - HALF as much light allowed in
Sunday, March 1, 2009
Measurement Review
• Aperture (noted by f ): 1, 1.4, 2, 2.8, 4, 5.6, 8, 11, 16, 22, 32, 45
• Shutter Speed (measured in seconds or fractions thereof): B, 15, 8, 4, 2, 1, 1/2, 1/4, 1/8, 1/15, 1/30, 1/60, 1/125, 1/250, 1/500, 1/1000, 1/2000, 1/4000, 1/8000
• ISO: 25, 50, 100, 200, 400, 800, 1600, 3200
each step to the right - HALF as much light allowed in
Sunday, March 1, 2009
The Sunny 16 Rule
• This is a GREAT starting point to learn expoure
• Normal Sunny Day outside
• Set aperture to f/16 and shutter speed (reciprocal seconds) to ISO film speed
• For example, for ISO 100 film, choose shutter speed of 1/100 second (or 1/125 second)
• (f/16 + 1/100 second)^100 = Proper Exposure
Sunday, March 1, 2009
Now go out and take properly exposed Photos!
Sunday, March 1, 2009