Pillars of photography

1
Pillars of photography

• Or
• The Exposure Triangle

2
The Power Players

• Aperture
• Size of the hole that lets light into the camera
• Shutter Speed
• How long the light is allowed to enter the camera
• ISO
• How sensitive the media recording the image is
  to light

3
Aperture

• The hole story

4
Aperture

• The aperture is the hole that allows light to
  travel through the lens of the camera.
• Likely one of the most quoted, and least
  understood photographic term.
• What was your aperture setting?
• F 16
• Looks really good
• Generally speaking, people ask about aperture
  settings, however they dont ask about the ISO
  setting or shutter speed.

5
Aperture

• A normal issue people have when discussing
  aperture is that a large number results in a
  small hole.how?
• The aperture value, often referred to as an
  F-Stop comes from a mathematical equation.
• Focal Length of lens / Physical size of opening
• 100 mm lens/ 25mm opening F4
• 100 mm Lens/ 10mm opening F10
• You will get a bigger number with a smaller hole
  and a smaller number with a bigger hole due to
  the math of division.

6
Aperture

• Another thing that messes people up is how is
  F5.6 to F6.3 twice the light?
• Again, this is a math thing.derived by focal
  length of lens, physical size of the opening and
  the good old (pi)r2
• A larger aperture allows more light to enter the
  camera in less time, this normally equates to a
  faster shutter speed. Conversely, a smaller
  aperture will normally make for a slower shutter
  speed.
• One of the biggest things you need to know about
  aperture to get started in photography is this
• It controls depth of field

7
Depth of field

• How much of your image do you want in focus?
• Just the persons face, I want the background
  blurry
• Small F-Number, (i.e. F5.6), this will keep the
  subject sharp while blurring the background.
• EverythingI want it all
• F16 to F22 are good numbers for keeping the
  entire image in focus.
• For example

8
Shallow DOF

• Settings for this shot were
• ISO 100
• Aperture F6.3
• Shutter Speed 1/320th of a sec
• Focal Length 163mm

9
Deep DOF

• Settings for this shot were
• ISO 100
• Aperture F22
• Shutter Speed 1/13th of a sec
• Focal Length 28mm

10
What is Depth of Field?

• Depth of Field is a term put to the amount of
  image that is in acceptable focus.
• There is lots of tecnobabble on this subject,
  however suffice to say that the following rule of
  thumb applies to your focal point
• Two thirds behind
• One third in front

11
Tecnobabble
Focal Length (mm) Focal Distance Depth of Field
10 0.5 (1.64 ft) 0.482 (1.581 ft)
20 1.0 (3.281 ft) 0.421 (1.381 ft)
50 2.5 (8.202 ft) 0.406 (1.332 ft)
100 5.0 (16.4 ft) 0.404 (1.325 ft)
200 10 (32.8 ft) 0.404 (1.325 ft)
400 20 (65.62 ft) 0.404 (1.325 ft)
Based on an aperture of F4
12
Small Aperture

• Aperture value F22
• This small aperture opening forces the shutter to
  stay open for a longer period of time, this
  allows you to make water seem silky.
• Smaller apertures normally require a tripod
• Almost everything in the image is in the same
  focus as a small aperture allows for greater
  depth of field.

13
Large Aperture

• Aperture Value F5.6
• The large aperture opening allows a great deal of
  light into the camera in a very short period of
  time, as such, the shutter speed will be
  increased significantly.
• Backgrounds are normally blurred with large
  apertures as the shutter isnt open long enough
  to capture all of the reflected light and detail
• Large apertures can be used easily for hand held
  shots

14
Mid-range Aperture

• Aperture value F8
• Mid-range apertures will allow you to have
  greater depth of field while still blurring some
  of the background.
• This can be useful when you are trying to capture
  larger groups of people, or there are subjects of
  interest in the general proximity of your main
  subject.

15
Aperture F13

• I chose F13 for the relatively deep depth of
  field, however I didnt want the shutter open so
  long as to make the waves in the background blur.
• Good texture in the foreground and lighthouse in
  acceptable focus in the background gives the
  person viewing the image a sense of the location
  and time of year.
• Darker lighting and dark clouds set the mood.

16
Aperture F5.6

• Applied a shallow depth of field on this shot to
  isolate my primary subject.
• I wanted to show the male to be ever vigilant
  while the female was feeding.
• Female and background are blurred, foreground is
  limited in focus.
• Male in sharp focus with light reflection in his
  eye.

17
(No Transcript)
18
Aperture

• Questions?