A short very basic presentation on the basics of proper exposure. A look at aperture, shutter speed & ISO

1. Exposure Basics:
Learn to Correctly Expose Your Photographs
Presented by Don Hazelwood
Sunday, March 1, 2009

2. 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

3. 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

4. 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

5. (Aperture + Shutter Speed)^ISO
= Exposure
Sunday, March 1, 2009

6. (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

7. (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

8. (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

9. (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

10. (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

11. (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

12. (Aperture + Shutter Speed)^ISO
= Exposure
2
Now for photographical math
Sunday, March 1, 2009

13. (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 opening
45 being the smallest
each step to the right - HALF
as much light allowed in
Sunday, March 1, 2009

14. (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

15. (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

16. 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

17. 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

18. Now go out and take properly
exposed Photos!
Sunday, March 1, 2009