This presentation is for a lecture in the School of Creative and Performing Arts at the University of Calgary.

1. Rough History of Photography
Digital Sensors, Lenses, Zoom, Stabilization, Compression
Best Practices for Shooting Video
Week 4, University of Calgary Drama 571
Lecture prepared and presented by Dr. David Bunnell
Smartphone Camera Technology
Pelican Imaging's 16-lens camera
module is designed for next-gen
mobile devices coming in 2014.
1.

2. Rough History of Photography
• Mid 1800s Silver nitrate glass plates
• Early 1900s B&W silent “movies”
• Mid 1900s Colour “talkies”
B&W TVs
• Late 1900s LCD TV’s
Digital photography
Cellular phones
Internet
• Early 2000s Digital movie making
Smartphone cameras
2.

3. About Photographic Film
Plastic coated with photosensitive emulsion. When
light strikes the chemical it causes a reaction.
Different formulas have different sensitivities to
light. Film has a resolution of ~20 Megapixels.
Film speed is a measure of how much light is
required to cause the photochemical reaction.
Slower, less reactive, film has finer grain (resolution)
and better color fidelity. The camera shutter speed
and aperture needs to be set within narrow range
for successful photography.
3.

4. Digital Sensors
• Electronics control exposure time (shutter sound is
artificial)
• Photons (light) energize electrons in CMOS
(Complementary Metal Oxide Semiconductor) which
can be collected by picture elements (pixels).
• There are colour filters on each pixel to allow only Red,
Blue, or Green (RGB) light to pass to the
semiconductor element.
• Smaller sensor chips have physically smaller pixels =
more light is required to form an image.
4.

5. CMOS Sensor Chip
Sony Image Sensor
5.

6. Apertures and Pixels
Small aperture/lens = limited light, large
depth of field
Large aperture/lens = large amount light,
small depth of field
Small Sensor (slow film) needs more light
Many pixels on small sensor = light spillage
6.

7. Basic Optics
Object, aperture, Lens,
shutter, sensor/film
Small aperture gives
greater depth of field
7.

8. Format Sensor size Pixel Pitch Camera
1/2.5” 5.76x4.29mm <1 micron Camera Phone
1/1.7” 7.6x5.7mm 1.7 microns Compact camera
APS-C22.2x14.8- 5.7 microns Consumer DSLR
23.6x15.7mm
Full Frame 36x24mm 8.4 microns Pro DSLR
Sensors and Pixel Pitch
8.

9. Lenses
9.

10. Lenses
Five element “Optical glass” lenses (with
scratch resistant sapphire lens cover)
Limited (no) anti-reflective coatings
Purple haze on iPhone
Digital (not optical) zoom
10.

11. Noise
Sensors are made up of many tiny receptors, pixels,
which record light.
•Large pixels are more sensitive to light.
– Camera makers boost the gain in small sensors to
capture a usable image.
•On large sensors, each pixel is walled off to
prevent light from spilling over to adjacent pixels.
– Small chips with high megapixel counts have light
spillage (flares).
– Transistors under each CMOS pixel generate noise.
11.

12. Digital Zoom
• Smartphone cameras do not have optical
zoom - digital zoom crops a region and
expands the pixel size. No increase in
resolution or number of pixels.
12.

13. Compression
• Image is compressed to reduce storage
requirements.
• 8x8 blocks are averaged
• Static areas (from frame to frame) copied.
– Moving objects produce ghosts and blurring
– Samsung allows editing of unwanted moving objects
• Dedicated microprocessors in cameras can
compress on-the-fly
13.

14. Infrared Sensitivity
Camera sensors “see” a broader spectrum
of light than the human eye. (Shine a TV
remote control into your camera). The
sensitivity to infrared may cause some
color distortion.
14.

15. Image Stabilization
Larger cameras may have “optical” stabilization
where the sensor is mechanically moved to
compensate for camera shake. Smaller cameras
typically do not have mechanical stabilization
and use “digital” stabilization that takes multiple
shots and averages the pixels.
Digital stabilization does NOT work for video
15.

16. 10 Best Practices for Shooting Video
1. Light your subject well
• Avoid backlighting
• Think of placing yourself (and the camera)
between the light source and the subject
• Fill in lighting with a big white cardboard, or
use the golden hour
1. Charge your battery completely
2. Have lots of room on your micro SD card
or internal memory for iPhone
3. Clean your lens
16.

17. Best Practices for Video (a few more)
5. Stabilize camera
• For stabilization, stand with feet shoulder width
apart and hold one hand underneath.
• Use a tripod or rest camera on solid object
• Minimize motion in poor lighting
5. Hold on your subject for at least 5 seconds
(you can always edit out extra)
6. Move in close to subject
• Don’t use digital zoom
• Improves audio if using onboard camera mike
17.

18. Best Practices for Video (a few more)
8. Use a Zoom recorder or some other
auxiliary microphone
• Capture some room noise
• Make sure you get mike tests and label the
audio Take 1 Take 2 etc. and log the takes
8. Initiate your shot with by giving signals:
• 3 – 2- (silence) then giving a finger gesture to
start. (If you say “action” you will seldom get a
good enough entry roll.
• Label video with Take 1, Take 2 by using a
clapper or sheet of paper before each take
18.

19. Best Practices for Video (a few more)
10. Give your shots texture and
professionalism by using various shot
angles, shot distances, camera movements
and don’t be afraid to experiment.
19.