Lesson 3 Light and Esposure (some slides identical to lesson2)

1. Lesson 3
The light
and the exposure

2. The light for a Photographer
Source : Type, Position, Color, enumeration
Quality : Soft, Hard, Diffused, dimension
Direction : Direct, Reflected, Main, Key, Background....
Quantity : Measuring and Metering - Light Meters
Capture : Exposure - Lens, Shutter, and Aperture
Rendering : Printing, Illuminant, ColorManagement
Photographer should MASTER the light

3. - White Balance
- Quality of light
- Quantity: ISO
- Exposure
Lesson 2 The Light
and exercises with the
camera in P mode

4. So let's start with White Balance
ILLUMINANT
daylight 5500K
Camera Settings
White Balance 5500 K
Camera WB 3000K Camera WB 9000 K

5. Just to remember what light is...
... for a photographer : electromagnetic waves
700 nm 400 nm
Monochromatic
790 Thz430 Thz
555 nm
540 Thz
IR UV
"white"
or colour
light
spectrums
sun
candle
flouresc
%
700 nm 555 nm 400 nm

6. The Sun Light - Daylight
Position: Infinite distance = parallel rays!
Atmosphere change white balance
and also diffuse the light
White Balance
daylight: ~5500-6500 Kelvin
rise/set : ~3000 Kelvin
6000 Kelvin
atmosphere filter
3000 K
5500 K

7. Sunlight in a cloudy day
Cloud filter
sun rays 6000
diffused
filtered
light
7000K
Color : 7000-9000 Kelvin
Position: Large sky area or full sky
Completely Diffuses light
Completely different light conditions!

8. In the shadow ?
Objects and area in the shadows...
are not black, as they get light from
secondary source... like the lights reflected
from our sky... like during twilight
Color of the sky / shadow? : 10.000 Kelvin
5000 Kelvin
10000 KELVIN

9. White balance values....
Monocromatic Lights: Lasers, Color Filtered, Sodium lamps...
1000 - 2000 K Candle light, Fire
1500 - 3500 K Tungsten lamps, Sunrise, Sunset
5000 - 6500 K Daylight, Xenon lamps, Flourescence for video
White led for video, Flash, Carbon Ark....
6500 - 9000 K Cloudy sky
9000-10000 K Twilight
All Continuos spectrum light sources are
good for photography !
Flourescent tubes, and discharge lamps (mercury, high
pressure sodium, HID, led..) have not a continuos spectrum,
non uniform freq green/magenta, and change in time!
??
??
very bad for photography, only scientific applications

10. Digital Camera White Balance
A
WB modes, some camera also shows Kelvin values
AUTO White Balance, is really advanced today, (avarage)
Perfect when light conditions changes fast
White object
Unknown
illuminant
Manual
setting
of white
balance
White object
reflects the
illuminant.
Camera balances
that illuminant as
reference white
daylight cloud flash tungsten flours shadow auto set
~5000K ~7000K ~5000K 2500K 6500?? 8000K AUTO custom
PRE
PRESET: YOU SET WB!
Exercise!!

11. I had never set WB in the film era...
Each color film was
balanced only
for a specific Wpoint
few options:
Daylight or Tungsten
For 50 years... cloudy day were bluish
Sunrise/set and indoor were yellowish...
You can keep your camera to Daylight WB!
WB recalibration was also possibile
during printing, it was done
automatically for cheap printing...

12. On my camera
Change the white balance
in 5 seconds...
Set a specific white point
in 15 seconds...
Think!

13. - White Balance
- Quality of light
- Quantity: ISO and Metering
- Exposure Compensation
Lesson 2 The Light
and exercises with the
camera in P mode

14. Visual perception of light
Sunset / Sunrise Sun at Zenith
balanced, warm light 3000K short shadow / hard
Relaxing confortable Oppressive and stressful

15. Light quality and direction on details
Accentuation of fine details Masking of fine defects
hard light soft light

16. Hard and soft light
Hard
Soft
& shadows
relative small & far source
relative big and close source or multidirectional

17. Diffused & ambient light are soft
Light comes
from all directions
at same intensity
(Cloudy sky on sand)
or so many sources
that we can
approximate them
as completely
diffused light
(but shadows...)

18. Making light softer
Diffuser: the tent Reflect on the wall/cealing
Make it
bigger...
Get closer

19. Making light harder
Making smaller / masking Going far away
Parabola, Ellipse, lenses
to concentrate Masking reflections

20. Simple light setup for portrait (1 light)
softbox
main light
reflector
camera
shadows
model
background
SOFT
LIGHT

21. Simple light setup for still life, objects
black background
bright
spot
spotlight
hard light
focused on
background
black masks
1 light
hard light
high contrast

22. Simple light setup for still life, glass
white background bright
spot
shadow shadow
spotlight
hard light
focused on
background
camera
glass
black edges
comes by
light
contrast
liquid & glass
retro-illuminated
no reflection here...
NO LIGHT!

23. 4 lights setup classical portrait (advanced)
softbox
key light
reflector fill
camera
shadows
model
background
SOFT
LIGHT
masks for background
Hair Fill
spot light
back
ground
light
snoot
2:1
1:1omni
ambience
color
gel
Keep it simple!
Do not use more 1
light until you master
it completely

24. - White Balance
- Quality of light
- Quantity: ISO and Metering
- Exposure Compensation
Lesson 2 The Light
and exercises with the
camera in P mode

25. Quantity: Under and over exposed
Too dark OK Too bright
lost in the shadows details burned out
UNDER EXPOSED OVER EXPOSED
GETTING THE RIGHT AMOUNT OF LIGHT (EXPOSURE)
IN THE PICTURE IS A CRITICAL PROBLEM
(That's why automatic exposure
cameras exists)

26. Exposure water example
Light is like rain
SENSOR or FILM are like water TANKS
Underexposed
Not enought water
(to float the duck)
Overexposed
Too much water,
overflow the tank
Good
Exposure Level
Good
Exposure Level
Good
Exposure Level

27. We can select different tanks (ISO)
Rain
100
400
level
good
exposure
On sensor and films this value is called ISO settings
100 ISO 400 ISO
large tank small tank
need lot of need 4time
water less water

28. ISO Sensitivity and Photography
Lot of light (day) = Lot of rain = low ISO
Few light (night/indoor) = Few drops = High ISO
100 ISO
800 ISO
100
High ISO = Less precision = low quality

29. LOW / HIGH and "Auto ISO"
LOW
HIGH These two errors, indicate
there is not sufficient or too
much light to take a picture
LOW = Increase ISO
HIGH = Dec
AUTO
ISO
Some camera have this function
they select select ISO automatically
New feature, impossible with film.
Could be useful, but create confusion
to the beginners. So please disable.

30. Modern FILM had ISO from 50 to 1600
HIGH ISO = larger grain = LOW QUALITY
Modern Digital Sensors
goes from 100 ISO 128.000 and more...
High ISO = more electric noise
LOW QUALITY
When possibile, it is better to work at low ISO
to get more quality...
but it is better a good noisy photo
than a completely undersposed and missed picture!
ISO: grain&noise considerations

31. On my camera
Change the ISO in 10 seconds
Think!

32. Exposure Histograms
and highlights
black
dark medium light bright white
quantity
sed
DIGITAL:
PLAY
BUTTON

34. On my camera
See the hystogram in 10 seconds
Think!

35. How camera meter the light?
Whatever is your subject, your camera will try
always to expose correctly to the "medium gray" value
original camera picture res hystogram
gray
black
white

36. Exposure Compensation, to get
exactly the exposure we want
LOT of light
Reflected
white objects
FEW Light
Reflected by
dark object
White subjects
(snow, paper...)
Compensate
+1 or +2
Compensate
-1 or -2
Black subject
(house, shadow)
white
results
(right hysto)
black
result
(left hysto)

37. On my camera
Compensate the exposure +1
in 10 seconds
Think!

38. Reflected light meter in the camera
Reflected Light Meter: Instrument that measure
the REFLECTED LIGHT
from objects
it is INSIDE modern CAMERA
Field of
view of
reflected
light meter
incident light
reflected light
measure the light
in the "pink: area

39. The Reflected Light meter in the cameras
Each camera has different systems
but all based on reflect light from
the scene.
Advanced cameras can have multiple
operating mode of the light meter.
Multizone and Matrix have today 2000
color points, with databse
scene comparison to get best EV
ltizone or Matrix
but also: faces, average, and....
LIGHT METERING MEASURING AREAS
Under OK Over
Exposed Exposed
READ THE MANUAL

40. Matrix Mode, or automatic mode... full scene analysis
Under Exposed OK Over Exposed
SPOT mode.... measure only one point of the scene... and...
OK OK OK
Camera Metering systems
e -2

41. On my camera, in 15 seconds
Change metering area, Matrix,
spot
central
In spot mode, change the
spot point (if possible)
Think!

42. Critical Situation for metering
Wedding :-)
Snow
Light and Shadows
Birthday / Candles
Theather
a white/black
paper (TRY!)

43. Critical Situations for reflected meter
FireWorks
Flying birds
Studio
lights
backlight portrait
Flash
different metering
somtimes combined

44. Camera Modes today
LOVES YOU FULLY AUTO
Camera sets everything in
automatic mode: WB, ISO, Exposure
SceneRecogn
Landscape, Portraits, Sports.....
Camera sets everything in
automatic mode: WB, ISO, Exposure
but can do a little bit better
P PROGRAM MODE
Camera sets only correct exposure if...
you set : White Balance, ISO
Metering Modes, Compensation

45. Cheap camera & Mobiles phones
- WB White Balance (indoor, outdoor)
- ISO (or night mode = high iso)
- Exposure compensation
(or snow / document =
+2 compensation)
Think! if you understand framing, composition
light and exposure... you can get
great picture even with a cheap camera.

46. Think!
Set my camera in P mode
in 10 seconds

47. I set my camera in P Mode
- Subject, Framing, composition (1)
- I set the White Balance
- Light quality, soft, hard, direction...
- I set the metering mode
- I compensate exposure if needed
- I check picture and histogram
I REPEAT until I got the result I want
Thinking as a Photographer
after lesson 2

48. Next Lesson ( 3 )
Shutter and mode S
Diaphraghm and mode A
Focus and Autofocus
and of course exercises

49. Exercises
White Balance
Set the proper WB depending on light source different lamps
Use a white paper to store white balance
Obtain a bluish or yellowish picture
Light Quality: Studio
Same studio project/subject lesson 1 but with lights!
Try hard and soft light direction and background
Improve composition and do not repeat mistakes!
Metering and ISO and critical situation
Change ISO and see difference in picture quality
Use the Spot Metering for dark and white subjects
Compensate exposure for a white scene
Take picture of a white piece of paper and a black one
Take a still life picture of a transparent glass over
a white background. You need to compensate exposure