1. BTEC
Level 3 Extended Diploma in Creative Media Production
Unit 64: Motion Graphics and Compositing Video
The term pixel is short for
Picture element and pixels
are the small dots that
make up the images on
digital. They are the
smallest addressable
element in a display
device. Each pixel can only
be one colour at a time,
but because they are so
small they tend to blend
together from different
shades and blends of
colours .
Pixels and Colour
Colour Depth: this is defined by the number of bits per pixel that
can be shown on a computer screen. Data is stored in ‘bits’ each bit
represents 2 colours as it has a value of either 0 or 1 and the more
bits that there is per pixel the more colours that can be displayed.
These are some examples of colour depth:
Colour Depth Number of Colours
1 bit colour 2
4 bit colour 16
8 bit colour 256
24 bit colour True Colour: 16,777,216

2. Pixels and Colour
BTEC
Level 3 Extended Diploma in Creative Media Production
Unit 64: Motion Graphics and Compositing Video
Colour Depth- since each bit represents 2 different colours, its quite simple to work out the
number of colours for the various colour depths because the number of the colours it could be
would be 2 to the power of the number of bits per pixel:
Colour Depth of 4 bits would be 2 times itself 4 times:
2x2x2x2 = 16 colours
Colour Depth of 8 bits would be 2 times itself 8 times:
2x2x2x2x2x2x2x2 = 256 colours
Colour Depth of 24 bits would be 2 times itself 24 times:
2x2x2x2x2x2x2x2x2x2x2x2x2x2x2x2x2x2x2x2x2x2x2x2 = 16,777,216 colours

3. BTEC
Level 3 Extended Diploma in Creative Media Production
Unit 64: Motion Graphics and Compositing Video
Digital Cameras don’t have film instead they have a sensor and this sensor converts light
into electrical charges.
It takes the light and
focuses it through the
lens onto this sensor
made out of silicon It is
made up of a grid of tiny
photosites and these
photosites are sensitive
to light. These photosites
are usually referred to as
pixels as it is a
contraction of a picture
element and there are
millions of individual
pixels in the sensor of a
digital camera.
Each pixel on the sensor absorbs photons and releases electrons
through something that is called the Photoelectric Effect.
This is where electrons are emitted from metals and non metallic
solids liquids or gas as a consequence of their absorption of energy
from electromagnetic radiation of short wavelength such as
ultraviolet light for example.

4. BTEC
Level 3 Extended Diploma in Creative Media Production
Unit 64: Motion Graphics and Compositing Video
CCD - this stands for charge-coupled device and it is the image sensor that is used by most
digital cameras but some camera use CMOS which is complementary metal oxide
semiconductor technology instead and both of these image sensors convert light into
electrons. Once the sensor converts the light into electrons it reads the value of each cell in
the image. This electric charge is then transferred and converted to an analog voltage that is
amplified and then sent to an analog digital converter where it is turned into a number -
digitised.