Principles of video Technology
Key terms
What is aspect ratio?
Aspect ratio is basically two numbers separated by a colon
(:), for example 4:3 or 1.33:1. The first number stands for the width of the
screen and the second for the height.
Over a century ago the first film were projected on the
aspect ratio 4:3
However in the 1950s TV became
very popular
and film studios fell nervous. Some people even predicted the death of
cinema.
Aspect ratio is an image projection that describes the
relation chip between the width and the height of an image. For example movies
which are shot with a wide lens have an aspect ratio of an 16:9, which means
the width of the image area is twice the height. Whereas the traditional
television and computer display are designed aspect ratio of 1.33:1. Which
means the width of the screen is 1.33 times the height, almost a square.
Nowadays television screens use an aspect ratio of 16:9 due to the HDTV wide
screen.
What is composite video?
Composite video is
also known as base band video or RCA. Composite video is an analog video
transmission without audio (sound). That transmits image in the image data in a conventional National Television
Standards Committee (NTSC) television signal.
Composite video contains tone saturation and lighting information. It also
contains synchronization and
blanking pulses in one signal.
What is component video?
Component video is a signal that is split into two
components. The information is stored in three separate signals. Component
video is contrasted with composite video. The video information is combined in
to a single signal. Used in analog television. Component video cables do not
have audio they are paired with audio cables. So When you connect your TV to a play
station or a blu ray DVD player you use a component TV cable to connect the TV
to the DVD player or play station. To make the HDMI to have a very high
performance.
What is HDMI interface?
HDMI short for High Definition Multimedia Interface. HDMI
support two way digital communication between video source and video display
with just one cable. Before HD television most TV display pictures were known
as standard display at the aspect ratio 4:3. However HDTV on the other hand are
digital. They use information in ones and zeros. This information is carried
through the cable as electrical pulses. HDTV's have and Aspect Ratio of 16:9.
Compared to standard TV HD is a widescreen. Also HDTV display more colour than
standard television. Which than leads us to HDMI. HDMI was created by a group
of manufactures. HDMI make a hug difference to the image on a HD television. HDMI can cut down the amount of
cables needed.
What is PAL?
Pal short for Phase Alternating Line. PAL is a colour encoding
system for analogue television.
What is NTSC?
Is the video system or standard used in
North America and most of South America. In NTSC, 30 frames are transmitted
each second. Each frame is made up of 525 individual scan lines
Satellite and cable are two different way to broadcast
television. One advantage of cable is that it is less likely to get affected by
the weather but it is way more expensive than satellite television. Cable is
better for people who rent houses rather than people who want a long term
contract. Satellite can be disturbed by the weather but it cheaper. Not all the
time you get what you want. Cable is only available in the areas were the
provider offers service. However satellite can be offered any where because you
only need a dish facing the south. Also satellite is less of a hassle you only
have to pay one a year where as cable it's a monthly payment. Often satellite
and cable may both offer the same channels but with basic satellite you get
over 200 channels this is the same as a premium cable which makes satellite
better than cable. Cable only offers local channels whereas satellite offer
both east and west channels, sport channels and other international channels
that the cable does not offer
Whereas internet is everything at your finger tips. Internet
is easy to access. You can watch what you want when you want. Also if you need
to take a toilet break get the phone you can pause whatever show you are
watching. All you need is a internet connection. With terrestrial digital TV you
need an antenna with a strong signal which means you might need to upgrade.
Turning to distant stations is a big problem if the signal drops between a
certain level. But with internet TV you don't need to worry about programmers on
TV channels from other countries because they are at your finger tips. Movie
packages such as Amazon on demand Netflix and other similar companies are
available so there not missing a show or
watching the latest film problem. Changing the channel on a terrestrial digital
TV can be a problem because hanging the TV
channel take longer than analogue TV
because it takes the receiver more time to decode the signal. However terrestrial TV
is free. Unlike the internet there is a lot of cost involved with internet TV.
You need necessary accessories to connect to the internet such as power line
adapters or wireless internet. Not all shows have made it onto the internet
yet. Which means you need to keep you cable or satellite subscription to watch
everything you wish. TV companies do not show each and every episode online.
Terrestrial TV more channels come from online time to time and many cables and
satellite companies never offer you channels for free.
Overall I think that satellite TV is the best because with
now a day technology you can watch catch up TV and there option where you can
pause or rewind your show that you are watching and you can also watch the
latest movies just by paying a little extra. Whereas internet TV you have to
search what you want to watch and then it buffers when you watching it.
Satellite TV now gives you options to watch programs you missed a week ago. It's
easy and simple.
It's really interesting to know that technology has evolved
over time. One of the the main examples of that is cameras. One of the best
thing about digital cameras is that you don't need to shoot a limited amount of video you can shoot
as much as you want because of the massive amount of storage. Digital cameras don't
need cells they have a battery that you charge which can last you up to 3
hours. With digital cameras you don't need to
buy an expensive film. So you can capture alot of footage for free. The
first few cameras you had to wind the camera to make a film. Because technology
has advanced so much that no such activity is required for digital cameras. You
don't even have you worry about the footage being out of focus all what you do
is click that's all and move the camera to whatever place you want and let the
camera do its magic. Digital cameras are made with a face detecting system. You
don't have to worry about blurriness' anymore on a person's face or on a
abject. You can also blur out things in the background if you want to . digital
cameras allow you to edit you footage so you choose what part of the video you
want and which part you don't. You can upload the footage you have recorded to
your computer or laptop. so it's safe
and it doesn't get lost even if the camera gets damaged you still have the
footage and any pictures you have taken. It's easy to share your footage after
you have edited the footage you can upload it online. Digital recording cameras have a viewing
screen so you can see your footage once you have recorded the footage. Using a
digital camera is easier on the environment. So the world is encouraging moving
to a greener planet. Processing a film with a toxic is definitely bad for the
environment. With digital cameras say goodbye to processing. Thanks to editing
anyone and everyone can make a little movie based on anything editing allows
you to add many different images and overlap to different footage's over each
other to create a special effect .
We have used 2 different types of cameras the big Sony film
camera with the format AVCHD.mp4, and the digital SLR which uses the format
QuickTime.MOV. AVCHD is a recording
format that is used for recording high definition video. AVCHD is only made for
high definition digital video cameras. Which records on a high definition
signal using high efficiency technology. The MP4 format is made to compress the
video for it to be less in size. AVCHD
records high definition video for all sort of media which allows you to put the
video on DVD, memory card, hard drive disk and many other things. If there is
space on the recording media then it will allow you to record it does not
overwrite. Video can be searched for and played without any problem. AVCHD also
allows long recordings with high definition. AVCHD if is advanced camcorder
format. Digital video cameras can shoot
raw or compressed footage's. So can the DSLR but using a different format called
QuickTime MOV. QuickTime MOV is the most well know Apple format used file
format for video files. MOV can be used for many different editing code such as
Apple ProRes and Apple intermediate. Both Canon and the Nikon cameras use the
MOV format.
To undertake a good footage you need to look at the
following things: You have to make sure if the image is focused. Is the image
clear. The image must be clear not blurry. There are two types of focus auto
and manual. Auto focus only focuses on the lens area it also adjust itself to
the object it is focusing on, whereas manual focus can be controlled by the
person. Also to maintain a good footage you need to make sure there is not too
much or to less exposure. Exposure is the amount of light you have at your
scene. If it is over exposed there is too much light and if its underexposed
there is to less light. If it's under exposed the screen can go dark. If there
is too much light a object can look dark. Most importantly you have to look at
white balance. White balance is balancing the type of light. There are two
types of light day light and artificial light. Different kinds of light produce
different kind of tone. Different lights produce different types of colour temperatures.
In different place the light conditions change. There is a procedure you do
called white balance. It super improves the quality of the image there are
normally four options on a digital camera auto ,indoor, outdoor and manual(one
push). Set up you camera and lights the last thing you do is your white
balance. Sound, you have to make sure you sound clear to check thins you put on
a set of head phones and you check your sound. Composition is a adjustment to
make sure the position of you camera is appropriate. Last but not least is the
rule of thirds you must make sure that everything you want is in the screen to check
this you position your camera and look into the screen and check that nothing
is being cut that shouldn't; also nothing extra is being added something that
is not needed.
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