Digital Photography Advanced Skills

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Digital PhotographyAdvanced Skills

• Class 1
• John Byersjbyers2_at_mail.com

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Class survey results

• 1. Took the CCCCD Getting Started Digital
  Photography class
• Yes xxxx________
• No xxxxxxxx____
• 2. Your level of experience with photography
• Beginner xxxx________
• Intermed xxxxxxxx____
• Advanced ____________
• 3.Photography terms you are familiar with
• Film Speed ISO xxxxxx______
• Aperture f-stop xxxxxx______
• Shutter speed xxxxxx______
• Depth-of-field xxxxxx______
• 4. Your digital camera
• Canon (6)
• Sony (2)
• Olympus (2)

• 5. You share your photos via
• E-mail xxxxxxxxxxx_
• Website xxxxxxxx____
• CD xxxxxxxxxx__
• Your prints xxxxxxxxx___
• Service prints xxxx________
• 6. You have a computer (All)
• Dial-up modem xxxx________
• Broadband xxxxxxxx____
• 7. Your interest in these photographic themes
  (1 high, 2 moderate, 3 low)
• Portrait 10 2
• Architecture 3 6 3
• Landscapes 7 5
• Stills 6 5 1
• Sports 8 4
• Wildlife 6 2 5
• Other Good snapshots

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CCCCD Continuing EdDigital Photography classes

• Digital Photography Foundations in Digital
  Imaging
• Basics of digital photography designed for
  those with limited knowledge of digital camera
  techniques.
• Digital Photography - Advanced Skills Build on
  the skills learned in the Getting Started course.
  Topics include using advanced digital camera
  features editing techniques for improved photos
  organizing and archiving image files. Photo
  assignments to expand creativity.
• Materials
• Digital camera (Read the users guide!)
• Text (optional) Dennis Curtin, The Textbook of
  Digital Photography

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Foundations class covered

• Digital camera basics
• Capturing the image
• Zoom focus
• Exposure
• Lighting, color
• Composition
• Processing the image
• Sharing the results

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Foundations class topics

• Digital basics
• Controlling sharpness
• Getting exposure correct
• Using light and color creatively
• Understanding your camera lens
• Elements of composition and style

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Class topics and OPTIONAL textbook
chapters(Dennis Curtin, The Textbook of Digital
Photography)

• Digital basics chap 1, 2
• Controlling sharpness chap 4
• Getting exposure correct chap 3
• Using light and color creatively chap 5, 7
• Understanding your camera lens chap 6
• Elements of composition and style
• Editing techniques
• Printing chap 10
• Special purpose photos (macro, panorama) chap 11

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Goal of this class Activities to improve your
digital photography skills address your
interests

• Photo assignments, review feedback
• Portraits
• Landscapes
• Architecture
• ?
• Techniques capturing, processing, sharing
• Photo editing software, techniques, work-flow

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Taking a great photograph
Great scene or subject
Capture
Understanding
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Concepts (Why) How photographers think

• Softness, sharpness
• Highlights, shadows
• Color, tone
• Scenes, subjects

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Practice the way photographers work
Procedures (How)
Concepts (Why)

• Softness, sharpness
• Highlights, shadows
• Color, tone
• Scenes, subjects

• Motion, depth-of-field
• Correct exposure
• Light and color balance
• Composition, visualizing

Become intimately familiar with the features of
your camera
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Procedures (How)Particular to your camera

• Display / controls
• Viewfinder optical / LCD
• Exposure / ISO controls
• Menu / setup
• Resolution / quality settings
• Storage media
• Computer connection
• Lens (zoom, macro/8 focus)
• Flash
• Battery
• Mastering your camera will improve your results

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TypicalCameraFeatures
Read your camera users guide
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Digital film is a grid of electronic light
sensors
Charge-coupled device (CCD) or complementary
metal-oxide semiconductor (CMOS), mosaic or
Foveon capture all perform the same basic
function
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Converting light to digital data

• Grid of photo sensors converts light energy to
  electrical charges
• Charges are converted to digital data
• Digital data is stored as image file in camera
  memory

Light
Light
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How a digital camera sees color
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Digital camera basics Pixels (Picture Elements)

• Digital photos are made up of tiny squares called
  pixels
• This image is made from jelly beans each jelly
  bean represents a pixel
• Megapixel 1 million pixels
• The number of megapixels that a camera has
  defines its maximum resolution

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More pixels higher resolution more detail
Detail improves as number of pixels increases
from 8x6 to 480x360 172,800 pixels
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Image size in pixels (resolution)

• This image contains 1600x1200 1,920,000 pixels

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Image size (resolution) settings High, Medium,
Low (Large, Medium, Small)

• Comparison Low and high image resolution

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JPEG compression (quality) settings High,
Medium, Low (Normal, Fine, Superfine)

• Comparison High compression (normal or
  basic quality)
• Low compression
  (fine or superfine quality)

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Pixels, print size camera memory capacity
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Image file types when shooting pictures

• JPEG (Joint Photographic Experts Group)
• Popular, highly effective imperceptible quality
  loss at low compression levels
• File size depends on image content and level of
  compression, but often one-tenth the size of
  comparable TIFF file (uncompressed)
• Lossy image quality is irretrievably lost every
  time an edited JPEG file is resaved
• Can be saved as (converted) TIFF file on computer
• TIFF (Tagged Image File Format)
• Large file size
• Bitmap image retains full image quality
• Optional, lossless compression
• RAW
• Non-interpolated output from camera image sensor
• Offers highest versatility for editing on
  computer may require special software to view
  and convert for editing
• Larger file size than JPEG, but less than
  one-half the size of comparable TIFF file
• Can be saved as (converted) TIFF, JPEG or PSD
  file on computer

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Image file types after downloading from camera

• Editing
• Save edited photos in non-lossy Photoshop PSD or
  TIFF format if further editing is planned not
  JPEG
• Other non-lossy editing software formats Paint
  Shop Pro PSP
• Viewing, sharing
• Use JPEG for email, slide shows
• Adobe PDF can be used to create compact slide
  shows
• Printing
• On home printer, use original JPEG image, or
  edited JPEG image saved in PSD format
• Sending to lab, use high quality (low
  compression) JPEG or TIFF
• TIFF is the most widely used format by publishers

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Image size aspect ratio widthheight

• Most digital compact cameras are 43 (like
  computer screens)
• Most digital SLR cameras are 32 (like 35mm film
  6x4 prints)

(Not shown to scale)
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Sensor physical size compared to 35mm film
Sensor size of typical 2- to 8-megapixel compact
cameras are much smaller than 35mm film image area
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Sensor physical size is larger in digital SLR
cameras
The physically larger sensors in DSLR cameras
have larger pixels, providing improved dynamic
range, better signal/noise ratio, and higher max
ISO
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Lens focal length multiplier effect is common
in Digital SLR cameras

• DSLR camera lens focal length is generally
  specified as 35mm film camera equivalent 50mm
  lens normal (human eye field of view)
• Camera image sensors are typically physically
  smaller in size than 35mm film frame (24 x 36mm
  1.4-inch width)

Image sensor size as compared to 35mm film frame
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Focal length of lens describes its magnifying
power

• On some digital cameras, focal length is
  expressed as 35mm film camera equivalent
• Higher focal length number indicates a greater
  image magnification
• Telephoto 100-300mm
• Normal 50mm
• Wide angle 18-35mm
• Typical point shoot camera 3x zoom range
  35-105mm

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A telephoto lens crops the scene tighter than a
wide-angle lens
Collection of photos taken from same position
with lenses ranging from wide angle to telephoto
24mm, 35mm, 50mm, 100mm, 200mm, 300mm
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Smaller image sensor crops the scene, effectively
providing a focal length multiplier effect in
digital SLR cameras
35mm film
Digital SLR image sensor
50mm normal lens in typical DSLR camera
performs like a 80mm short-telephoto lens. 28mm
wide-angle lens performs like a 45mm normal lens.
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Photos can be sharp or unsharp in different ways

• Motion freeze, or portray movement using blur
• Shutter speed fastest determined by overall
  scene brightness (and ISO setting) for given
  aperture setting
• Other factors subject speed, direction, and
  distance from camera lens focal length (zoom)
• Depth-of-field (near-to-far range of apparent
  sharpness) small (portrait) or large
  (landscape)
• Lens aperture widest opening determined by
  lens speed (faster lens has larger maximum
  aperture, more )
• Other factors subject distance from camera lens
  focal length

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Visualizing depth of field

• The near and far limits of depth of field
  (planes A and C) are parallel to the plane of
  critical focus (B). The depth of field is not
  evenly divided. At normal shooting distances,
  about one-third of the depth of field is in front
  of the plane of critical focus (toward the
  camera) and two-thirds is behind it (away from
  the camera). When the camera is focused to a
  close object, the depth of field becomes more
  evenly divided.

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Aperture and depth of field
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Subject distance, zoom and depth of field
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Auto focus lock technique

• If focus is on distant object, close object may
  not be sharp
• Aim focus point at subjects face, press shutter
  button half-way down and hold to lock focus
• Recompose scene and then press shutter button all
  the way down to take picture

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Exposure is the amount of light reaching the
image sensor

• Proper exposure provides both highlight and
  shadow detail and saturated colors
• Underexposure shows some highlight detail, but
  lacks shadow detail and color
• Overexposure shows some shadow detail, but
  highlight detail is lost, and colors are washed
  out

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Interacting camera controls affect exposure

• A given exposure can be achieved using a number
  of different combinations of shutter speed,
  aperture and ISO
• Shutter speed light, motion blur
• Aperture f-stop light, focus depth-of-field
• ISO sensor sensitivity to light
• Choosing shutter speed and aperture is a
  balancing act between capturing motion versus
  desired focus depth of field softness,
  sharpness

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Inside the camera shutter speed
Shutter speed (seconds) is controlled by time
delay between two curtains
Faster shutter speed ? (freeze motion)
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Inside the camera lens aperture (opening)
Lens aperture is measured in f-stops. Largest
possible aperture is referred to as lens speed"
f/4 f/5.6 f/8 f/11
f/16
Smaller aperture, larger depth of field ?
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Using different combinations of shutter speed,
aperture and ISO for a given exposure
Light Sensor (ISO) sensitivity to light ?
increase
(Higher ? )
(Faster ? )
Shutter Speed (seconds) motion blur ? freeze
Aperture (f/stop) focus depth of field ?
increase

(Smaller ? )


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Changing to a faster shutter speed and larger
aperture, for a given exposure
Light Sensor (ISO) sensitivity to light
(Higher ? )
(Faster ? )
Shutter Speed (seconds) motion blur
Aperture (f/stop) focus depth of field

(Smaller ? )


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Changing to a smaller aperture and increasing the
ISO, for a given exposure
Light Sensor (ISO) sensitivity to light
(Higher ? )
(Faster ? )
Shutter Speed (seconds) motion blur
Aperture (f/stop) focus depth of field

(Smaller ? )


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Shutter speed setting affects exposure and motion
portrayal
Faster shutter speed ?
1/15 1/30 1/60 1/125
f/8 aperture
http//www.photonhead.com/exposure/simcam.htm
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Aperture setting affects exposure and focus
depth of field
Larger aperture ?
f/11 f/8 f/5.6 f/4
1/60-sec shutter speed
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ISO setting determines image sensor light
sensitivity

• Similar to film speed
• Higher ISO numbers provide higher light
  sensitivity ISO 200 requires half the exposure
  of 100
• In bright light, ISO setting of 100 is adequate
• Higher ISO settings can allow taking pictures
  without flash in low-light conditions and places
  where flash is not wanted, but introduce added
  noise (grain)

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High ISO settings add image noise (grain)
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Physically larger sensors ? less noise

• For a given ISO, Larger DSLR sensor produces
  lower noise level than smaller Point Shoot
  sensor

Noise level determines maximum usable ISO
setting Point Shoot up to ISO 400 or
800 DSLR up to ISO 1600 or 3200
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Selecting exposure modes

• On some cameras, exposure modes are represented
  by icons on a dial (Accessed via menu on
  some cameras)

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Camera exposure mode settings

• Automatic (AUTO)
• Exposure (shutter speed, aperture, ISO), white
  balance, focus and flash are set without your
  intervention
• Lets you concentrate on composition without
  paying attention to settings
• Semi-auto scene assist exposure modes
• You select from a variety of situations such as
  portrait, landscape, sports, beach, etc.
• Auto exposure system sets educated shutter
  speed / aperture combination for proper exposure

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Going beyond automatic mode settings

• Programmed Auto (P)
• You select aperture or shutter speed, and auto
  exposure system automatically sets the other for
  proper exposure
• Can also select WB, Flash, ISO settings
• Typically similar to Manual mode on some
  compact cameras
• Shutter priority (S, Tv)
• You select shutter speed needed to freeze (or
  deliberately blur) camera or subject movement,
  and auto exposure system sets the aperture for
  proper exposure

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Additional exposure mode settings

• Aperture priority (A, Av)
• You select aperture for desired depth of field,
  and auto exposure system sets the shutter speed
  for proper exposure
• Manual (M) (full manual some cameras)
• You select both shutter speed and aperture
  auto exposure is effectively disabled calculated
  exposure comparison is generally displayed

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Auto exposure system can go awry

• Most scenes contain continuous spectrum of shades
  of gray, ranging from pure black pure white
• The tone in the middle is called middle gray
• A subject uniformly of this tone reflects 18 of
  the light falling on it
• Auto exposure system is calibrated for middle
  gray subject

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Subjects that dont average out to middle gray
can lead the auto exposure system astray
Scenes lighter than middle gray produce an image
that is too dark
Exposure increased by one stop (1) to lighten
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Exposure compensation examples

• White plate
• Gray plate
• Black plate

EV1
EV 0
EV-1
Without compensation
With compensation
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Light from the sun or a light bulb contains a
mixture of colors
"White" light consists of different colors in
different proportions. The overall color cast ,
or hue, of the light changes as the proportions
of the colors change. Although different light
sources have different colors, the eye doesnt
perceive the subtle differences when viewing a
subject in real time the brain automatically
compensates for sources of light that we assume
are white, but photos capture it
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Proper color balance is achieved using camera
White Balance setting
Improper WB
Proper WB
White balance setting removes unrealistic color
casts by taking into account the light source
color temperature
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Image sensors can be balanced to match the light
of a particular color temperature
Incandescent
Fluorescent
Daylight

• White Balance (WB) control adjusts relative
  sensitivity of sensor to neutralize color
  temperature of ambient light, eliminating color
  cast and providing accurate color capture
• Incandescent (indoor) setting matches warmer,
  reddish color of incandescent lights
• Daylight (outdoor) setting matches cooler, bluish
  color of daylight
• Automatic white balance (AWB) works well in
  non-critical situations

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Auto white balance can be led astray

• Predominance of subject warmth or coolness may be
  overcompensated
• Absence of white or colorless object
• Mixed lighting

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Digital cameras offer a variety of white balance
(tone) settings

• Auto white balance uses a best-guess algorithm
  within a limited range - usually 3000-7000 K 
• Custom allows you to take a picture of a known
  gray reference under the same lighting, and
  specify that as white for future photos 
• Kelvin allows setting the color temperature over
  a broad range
• The remaining six settings are listed in order of
  increasing color temperature some cameras also
  offer "Fluorescent H" setting, designed for
  daylight fluorescents
• Preview color balance by looking at scene in the
  LCD monitor

Camera WB setting may be remembered must be
reset!
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Flash modes control when the flash fires

• Auto (default) flash fires only when available
  light is inadequate for proper exposure
• Anytime flash always fires, regardless of
  amount of available light
• Red-eye Reduction separate pre-flash (or lamp)
  fires just prior to flash that actually takes
  picture (may be available as auto and/or anytime
  mode)
• Flash Cancel flash is turned off available
  light is used for exposure
• Slow Sync (available on some cameras) after
  flash fires, shutter is kept open longer to
  lighten background in night scenes

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Flash exposure compensation

• Offered on most DSLR cameras
• May be referred to as flash fill ratio control
• Adjusts flash output independently of camera
  exposure compensation control, which affects both
  ambient and flash exposure
• Increase or decrease the amount to lighten or
  darken the effect of the flash
• External flash and internal pop-up flash may use
  the same compensation control

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Pleasing photo composition places visual elements
in a balanced, harmonious fashion

• Use the rule of thirds to create a balanced
  composition
• Imagine the scene divided vertically and
  horizontally into thirds (tic-tac-toe)
• Place subject focal elements at the intersections
  and along the axes
• Dont put neat stuff in the center of the frame

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Desktop darkroom tasks to process image

• Transfer files from camera to computer
• Edit image files
• Crop/resize
• Enhance
• Save edited image files on computer
• Share results (print, e-mail, online)

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Addressing your interests

• Photo assignments, review feedback
• Portraits
• Landscapes
• Architecture
• ?
• Techniques capturing, processing, sharing
• Photo editing software, techniques, work-flow

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One of the most useful digital camera features is
the histogram display

• it may also be one of the least understood
  features!
• Many digital cameras have a histogram display
  feature that provides exposure analysis

Many cameras can be programmed to display the
histogram on the LCD monitor immediately after a
shot is taken, or later when images are being
reviewed
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The histogram shows the brightness levels
contained in the image, from darkest to brightest

• An image recorded in 8-bit mode has 256 discrete
  brightness levels between absolute black (0) and
  absolute white (255)
• 18 gray (the calibration point for auto exposure
  metering) has a numeric value of 128 half-way
  between absolute black and absolute white

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Image detail is best recorded when light hitting
the sensor falls within a range of about 5
f-stops

• Each f-stop is a doubling (or halving) of the
  amount of light hitting the sensor
• Any part of the image that receives too much
  light will be blown out and highlight details
  lost too little light, its rendered as black
  and shadow details lost

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There is no such thing as a perfect histogram

• Auto exposure light meter computes exposure to
  render 18 reflectance gray card as a mid-tone
• Most appropriate" exposure places mid-tones in
  the scene roughly half-way between the darkest
  and the brightest values

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Histogram example (shots exposed about 3 stops
apart)
Lost shadow detail in trees
Blown-out highlights in sky
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Digital compositing using Photoshop
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There is no such thing as a bad histogram
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Mastering photo exposure

• If your camera supports histograms, set display
  for combined thumbnail and histogram for 5-10 sec
  after every shot
• Get in the habit of glancing at display
• Exposure bracketing

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Photo assignment for next time

• Self portrait

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A self-portrait journal (Photos by Tim Dinofa,
www.dinofa.com)