E. Pupil Resources 1 - Imaging Partnership

Imaging
Partnership
STEM PUPIL RESOURCES
Light We Can See
LESSON ONE
What you will learn:
• That some light is in the ‘visible’ range, some is also ‘invisible’.
• How photographers use natural light and how it can be modified.
• How photo flash works.
• How and when to use flash in their photography.
What you should be able to do:
• Demonstrate how to use natural light to take photographs
• Explain how photo flash works.
• Demonstrate how to use photo flash in photography.
• Take photograph using correct techniques as required.
Herschel Experiment
In 1800, Frederick William Herschel
discovered that:
• Each colour of the spectrum has
a different temperature*
• Light exists outside the visible
spectrum
• The highest temperatures are in
the range outside visible light
• * Sir Isaac Newton discovered
that white light directed through
a prism would divide into many
colours in 1672
Herschel Experiment
Recommended video:
https://www.youtube.com/watch?v=-JdhySH2PMc
Why Do We Need Flash?
• It takes a lot of light to expose a vivid image onto a sensor.
• For most indoor photography, where there is relatively little
ambient light, you either need to expose the sensor for a
longer period of time or increase the light level to get a
clear picture.
• Increasing the exposure time doesn't work well for most
subjects, because any quick motion, including the
movement of the camera itself, makes for a blurry picture.
Photo Flash
• Electronic flashes are a
simple, cheap solution to this
problem.
• Their purpose is to emit a
short burst of bright light
when you release the shutter.
• This illuminates the room for
the fraction of a second the
sensor is exposed.
How Flash Works
• Flash guns are powered by 1.5 volt
batteries.
• They need to produce several
hundred volts to fire the flash.
• This is where the capacitor comes
in – people compare it to a
battery, but it can only store
electricity, not create it.
• When the flash is fired, the
capacitor releases enough energy
and then re-charges (which is why
it always takes a minute before you
can take the next photograph).
Available Light Portraits
• Although many photographers
are masters of flash, for most of
us, the results are less
impressive and we can often
get much more effective
results by photographing
indoors, near a window.
• This means that we can use
light and shade to good effect
and in portraits, to make our
subjects look more 3D.
Available Light Portraits
• Sometimes though, the shaded side
of the face can be too light.
• We can lighten this by using a
reflector, or white card to bounce
the light back into the shaded area.
• Also, if it’s too light, then use a black
card to darken.
• If you want to experiment, then
coloured reflective cards can give
an interesting glow!
Flash Photography
• Now, using your flash,
take a series of images of
each other.
• Try to achieve the same
effects of light and shade
you got before.
• Again, experiment – what
happens if you put
coloured film or tissue
paper over the flash, for
example?
My Images
My Images
My Images
My Images
So what have we learned?
• We learned that there are different kinds of light, some
visible, some invisible
• We learned how photographers use light
• We learned how photo flash works
• And we took photographs using both natural light and
flash photography