Beginning Digital Photography
for Campus Life at Cornell
Lynn Purdon Yenkey
January 14, 2010
All photographs Copyright Lynn Purdon Yenkey
Intro & Overview
How much camera do I need? (15 min)
- camera options, megapixels, & storage media the casual
photographer needs to make quality pictures
Upload pictures to the computer (3 min)
- camera cables vs. card readers
Edit pictures to crop, remove redeye, & more (15 min)
- JPG compression (benefits and dangers)
- demo of Picasa software for basic picture editing
Basic photography concepts (20 min)
–composition, exposure, what to think about before you click
Mega = million / pixel = light-capturing
elements in a camera’s sensor
2048×1536 sensor elements = 3,145,728
~ 3.1 megapixels
Defines the primary resolution of photos
At the highest image quality setting
Use camera settings to lower resolution
and save disk space
How many megapixels is enough?
What is the highest image quality you want to achieve?
What do you want to do with your photos?
Web: use the lowest resolution: in camera or save a new version
Personal prints / home printer quality: average quality settings
Gift quality prints, cards, fine art: high quality
Cost: more resolution costs more, but less than it used to
Beware of too many megapixels packed into small sensors
Memory: shooting & storage
Get extra storage cards if you plan to shoot a lot
Faster cards mean faster shooting & downloading (MB/s)
Archive! External hard drives, DVDs, online storage companies
Storage Card Memory Examples
32 MB 64 MB 128 MB 256 MB 512 MB 1 GB
1 megapixel 92 180 363 730 1460 2923
2 megapixel 34 70 140 283 567 1135
3 megapixel 25 51 105 212 424 852
4 megapixel 16 32 64 128 256 512
5 megapixel 11 25 50 101 203 407
6 megapixel 10 20 40 80 160 320
7 megapixel 9 18 38 75 150 301
8 megapixel 8 16 32 64 128 256
These numbers may vary by camera and assume using the highest quality image setting.
How many images can you store on a memory card?
How many will you shoot in an outing?
What size print can I make?
What is your starting
What is the output
Photo lab: 240-300 ppi
Megapixels at 300 PPI at 200 PPI
2 5.8" x 3.8" 8.7" x 5.8"
3 7.1" x 4.7" 10.6" x 7.1"
4 8.2" x 5.4" 12.2" x 8.2"
5 9.1" x 6.1" 13.7" x 9.1"
6 10.0" x 6.7" 15.0" x 10.0"
8 11.5" x 7.7" 17.3" x 11.5"
12 14.1" x 9.4" 21.2" x 14.1"
16 16.3" x 10.9" 24.5" x 16.3"
22 19.1" x 12.8" 28.7" x 19.1“
Other features to consider
Get good optics—better lenses make better photos
Optical zoom is better than digital zoom
More controls mean more control
As your skills grow, you might prefer more control
Shutter lag: the best way to miss the moment
Compare and get the least you can find (measured in
fractions of seconds)
Compensate by holding trigger half-way down to
pre-focus and set exposure readings
Battery life. Carry extras!
Camera software provided
Camera is just another drive
USB cable (drains camera battery)
Digital media drives
accommodate different card sizes
Upload faster than cables
File Compression & Color Format
JPEG: benefits and risks
Small, med, large in camera
“Lossy” compression. Data is lost on each re-save.
Save a copy to edit & keep the original unchanged.
sRBG for the Web—smallest color gamut.
Some online printers now ask for sRGB.
Adobe RGB: bigger color gamut, use for prints
Organize images on your computer
Share images on web albums—public and private
Be creative: movies, collages,
Exposure’s Basic Ingredients
ISO controls sensor’s sensitivity to light
Higher #s for low light or fast action (ISO 400 & up)
Lower #s for bright daylight, blurring, finer quality
Aperture / f - stop
Controls volume of light reaching the sensor
(like a faucet on high or low)
Controls depth of field—how much or little is in focus
Controls how long light reaches the sensor
Controls appearance of movement—blurs or stops action
Controls sensor sensitivity to light
Next level up means twice as sensitive to light
High number = high light sensitivity
Enables faster shutter speeds or smaller apertures
Higher ISO adds noise (“graininess” in film)
ISO 400 typical for sports outside
ISO 1600 typical for low light
Low number = low sensitivity
Enables long shutter speeds or wider apertures
Use to intentionally blur or defocus background (DoF)
ISO 100 or 200 for bright daylight with slow-moving
subjects or stills
How much light enters the lens opening
Moving up or down one f -stop halves or doubles the
lens opening (and the amount of light entering lens)
f /2.8, f /4, f /5.6, f /8, f /11, f /16, etc.
Inverse of shutter
usually needs faster
– Av or A mode
Aperture and Depth of Field
DoF is a defining characteristic of photography
Low f - stop = more light, less DoF
High f - stop = less light, more DoF
f /2.8 ~ “wide open”:
smaller DoF (less is
f /16: larger DoF:
2 ft to infinity in focus
Focus to create
get close and zoom
or use macro
Using Depth of Field
Small apertures (f #) shorten the area of focus, create
blurred backgrounds (“Shallow depth of field”)
Centers attention on what is sharp.
Shutter Speed and Movement
Shutter speeds double (approx.) with each setting.
1 sec, ¼, ½, 1/8, 1/15, 1/30, 1/60, 1/125, 1/250, 1/500, 1/1000
Inverse of aperture—
faster shutter speed
needs wider aperture
(smaller f number)
Do you want to
show movement or
Low light needs
– Tv mode
f /16 Rule
Set shutter speed equal to ISO
ISO 200, then shutter is 1/200 – 1/250 sec
Aperture = f /16
Shift aperture + shutter up or down
(inversely) to get the desired setting.
For ex: 1/1000 sec @ f /8
Shutter Speed and Movement
Increase ISO to
improve stop action or
shoot in low light
Chances of blur increase
with low shutter speeds
Pre-focus where you
want to stop the action
Experiment with showing
movement or stopping it
Composition: Rule of Thirds
A rule in visual arts to
Divide the image into thirds
vertically and horizontally.
Place the point of interest
at one of the red
Place horizon lines at
thirds, not in the middle.
Break the rule sometimes.
Rule of Thirds
Careful composition improves even casual snapshots.
Lens Choices / Focal Length
How much do you want to show?
Appearance of a larger depth of field so more is in
Widest angles can distort corners
Similar view to what the human eye sees
Compresses the subject and background
Appearance of shorter depth of field
Hand shake is also magnified, so you tend to require
faster shutter speeds (& higher ISO)
Be a lifelong photography student.
Think about what you want to come away with.
Get to know your camera.
Experiment—digital images are free, so
experiment & learn from mistakes.
Give self-assignments: capture blur, mood in low
light, fast action, different DoF…
try something new!
Get close to your subjects. Move around!
Get Prints Online
www.kodakgallery.com or Kodak Kiosk in stores
Camera Review Sites
www.digicamguides.com/learn/megapixels.html – a good description of how mega you need to get
http://www.digicamguides.com/print/ppi-print-size.html – megapixels and printing
http://en.wikipedia.org/wiki/Digital_camera#Image_resolution – a good description and table of different sensors and their resolutions
http://www.digicamguides.com/learn/digital-camera-terms.html – general digital & photo terms
These specs change, so please read latest manufacturer information.