are little squares or rectangles
that turn on and off.
Turn the pixel all the way on and
it is white. Turn the pixel all
the way off and it is black.
Turn the pixel halfway off and it
is grey. Grey is halfway between
black and white.
What if you want something other
than black, white or grey? For
this you have to turn off and
on certain colors.
A pixel actually consists of 3
colors: red, green, and blue. If
all 3 are turned on all the way,
you get a pure white color. If
all 3 are turned off all the way,
you get pure black.
If all 3 are turned on halfway,
you get grey. Black, white,
and grey are all 3 colors appearing
to your eye in perfect balance.
I find it interesting that the
only way to make a color appear
on a TV screen is to unbalance
the colors. For example, to get
bright red, you turn the red aspect
of the pixel all the way up and
you turn the other 2 aspects ---
green and blue --- all the way
down.
Some colors are derived by turning
on more than one color. For example,
bright yellow is achieved by turning
red and green to their maximum brightness
and turning blue completely off.
The more you mix the 3 colors -- red
green and blue --- the more color choices
you have. A digital TV is capable of
millions of different colors.
How many pixels does your digital TV have
to work with? It depends on your TV. Some
digital TVs are 720p TVs and some digital
TVs are 1080p TVs.
A 720p digital TV has 720 pixels to work
with in its vertical dimension. A 1080p
TV measures 1,080 pixels vertically. Yes,
you can measure your TV screen in pixels.
When you measure your TV with pixels, you
are not measuring inches or centimeters,
you are measuring pixel density. A 1080p
TV has more pixels per inch than does a
720P TV -- if both TVs are otherwise the
same size as they sit in your room.
All HDTV televisions are wider than they
are tall. The ratio of width to height
is 16 to 9. A 720p TV is 720 pixels tall
and 1280 pixels wide.Multiply the two
numbers together and you get the total
number of pixels on the screen.
720p is sometimes referred to as 1280 X 720.
1280 X 720 is the width times the height.
Multiply these 2 numbers together and you
get 921,600 pixels.
That's almost one million pixels. Therefore,
720p is roughly equivalent to a one megapixel
still camera. That is to say, each frame of
of video shot at 720p is, roughly speaking,
one megapixel.
An interesting aspect of Samsung's 720p is
that they actually give you a few more
pixels than 720. The actual aspect ratio
of the 720p Samsung TVs that I've looked
at is 1366 x 768.
The extra pixels are probably there to match
what Samsung offers in its computer monitors.
Rather than manufacture 2 sizes that are similar,
it appears to me that Samsung has settled on
1366 x 768 as a resolution that is slightly better
than 720p. However, instead of calling it
something else, Samsung calls it 720p.
Where does Samsung get the number 768 from?
It appears to me that this is a variation on
an old format which was 1024 X 768. Sometime
back, 1024 X 768 was the dominant computer
monitor size. It still is.
As of July 2011, 18 percent of the internet
browsing public still has monitors that are
1024 X 768. That's almost 1 in 5 people.
Back in December of 2007, 46 percent of the
Internet browsing public had 1024 X 768
monitors. Back then, almost 1 in 2 people
had 1024 X 768 monitors.
Again, in December of 2007, .02 percent
of the Internet browsing public had 1080p
monitors. That's 2 out of every 10 thousand
people.
1080p monitors are computer monitors that
have a screen resolution of 1920 X 1080.
More about 1080p later.
In July 2011, 4 percent of the Internet
browsing public has 1080p monitors. That's
roughly 1 out of every 25 people.
In 4 years (2007-2011), 1080p computer
monitors have grown from 2 out of every
10 thousand people to 1 out of 25 people.
1080p appears to be taking over the TV market
and is doing very well in the computer
monitor market. Based on what I see being
offered at my favorite online retailer, Newegg,
I expect 1080p to grow dramatically. Most
of the monitors offered at Newegg in August
2011 are 1080p.
In August 2011, the top five sellers at Newegg,
based on the number of reviews by buyers, are all
1080p monitors.
The point? The computer monitor
market and the market for televisions
are intimately connected. More and
more, I see these 2 markets converging.
I see an increasing trend towards TV screens
and computer monitors to have the exact
same screen resolutions. In August 2011,
both the computer monitor market and the
television market appears to be converging
around 1080p.
Her'e my source for computer monitor market
penetration statistics:
NETMARKETSHARE
To find the pages where I gathered information about
computer monitor market share, do the following:
- Look for the links on the left side of the page
- Look for Other
- Under Other, look for Screen Resolutions
- Click Screen Resolutions
- When you land on the Screen Resolutions page,
manipulate the month and year in the upper left-hand corner. - Change the month and year to see how the monitor sizes
that people buy year-to-year changes.
Here's an article that explains different screen
resolutions for HDTV much better than I do:
Quick Guide: HDTV Resolution Explained
The most helpful thing I find about the above article
is the relative unimportance of screen resolution. The
author does a very very good job of pointing out that
other factors are much more important.
This reminds me of something I've often observed and
that is that people place far too much importance on
things that are easy to measure. 720p versus 1080p
is very easy to measure. Therefore, people place a
huge amount of importance on it.
The author of the article points out that contrast ratio
is far more important. This makes total sense.
Think about it: In literature and in history, you often
hear of people traveling at night by the light of a full
moon. Of course, people also travel and move about by
the light of the tropical sun at 12 noon.
The contrast ratio of a full moon illuminating the Earth
versus a tropical sun illuminating the Earth on a clear
day must be at least one million to one. Our eyes are
able to see in bright light and in dim light too.
In other words, our eyes are able to work with some
rather remarkable contrast levels. It therefore makes
total sense that a HDTV with a great contrast ratio is
going to do a far better job of conveying visual information
than a monitor with slightly better visual resolution.
In other words, highlights and shadows are far more
important to visual perception than details are. Yes,
details are important, but without contrast, we would not
see detail anyway. Therefore, without contrast, detail
has no meaning.
Ed Abbott
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