Saturday, October 8, 2011

Hardware: TV - The Basics

Today TeamXbox is proud to launch the first chapter of our Hardware section. Considering the Xbox is the most powerful console when it comes to graphics, sound and online play, we considered that a hardware section of an Xbox related site can't be only reviews of peripherals.

Considering the Xbox specs, it's important that we discuss topics such as HDTV, Dolby Digital 5.1 sound, A/V amplifiers, speakers and more ...

Our mission is to have the ultimate resource for all the hardware you need with your Xbox in order to have the best gaming experience. With your feedback and help, these articles will answer all yours questions and also reveal the major details of tips and tricks when buying electronics. Yeah, we're doing shopping guides.

Introduction:

A few years ago a discussion about which TV is the best for your videogame console wouldn't have made any sense at all. Why? Simply: Consoles' graphics were just 2D sprites moving on your screen. Gone are the days when the screen characters were simple rectangular lines and later 2D figures.
In the last two decades we have evolved from 2D games with simple graphics (Miyamoto once said that Mario has a moustache because they couldn't draw a mouth!) to high-resolution graphics running at high frame rates, like Dead or Alive 3 or Unreal Championship.

To understand which is the best TV for your Xbox, we should first discuss the different technical terms associated to TVs and understand how a TV works.
If you want to run, you need to learn how to walk first, so in this first installment we're going to review the basics of TVs so we can later discuss HDTV and other advanced features. After all, those are an evolution of the technology developed for television.

It's always important to know first what a term means and in the case of TV, the television term comes from two latin words: Tele and Vision. The latin word tele means "in the distant" while vision comes from vîsum, which means "something seen". It's important to know this, since we'll see in later installments that this "something seen in the distant" is also the cause of lack of speed in the implementation of new technologies.

Although TV's technology is one of the greatest inventions, it works thanks to another technology, the one everyone of you have: the human eye's technology. In fact, the moving image is actually an illusion that relies upon several different properties of human perception. Let's see why we see in colors and how motion is achieved.

Color Vision: (and why we use an RGB model)
So many people think that displays use a Red/Green/Blue model (later on this) because those are the primary colors which, when mixed in different quantities, can make any color. But that's not the answer, since the real question should be why when we mix those primary colors we can see any other color? The truth is that this lies in the human eye's "technology".

The retina is the sensing element in the human eye and serves a similar purpose to a film inside a camera; Light is focused by a lens at the front of the camera onto a light-sensitive film at the back, to form a picture. In a similar way, light entering your eye is focused onto a light-sensitive tissue, which lines the inside of the eye at the back. This tissue is the retina, which is made of two main layers, a thin one called the pigment epithelium and a thicker one, made up of many layers of cells, that contains two types of photoreceptors, rods and cones, which are located at the bottom of the retina.

Rods are responsible for low level light detection and sensitive to blue/green, but they respond very little to red light. They are more numerous than cones, some 120 million. They are very light sensitive and motion sensitive but, like everything in nature, at a cost of something: resolution. In the center of the visual field, called fovea, rods are almost missing but are scattered elsewhere throughout the eye. At night, the fovea is very insensitive and most of the visual information is being carried by rods in the periphery of your eye. This is the explanation of why human beings see so poorly at night.

The 6 to 7 million cones are concentrated in the fovea, thus providing high resolution central daytime vision. Cones are the ones which carry the color information (human eye can detect over 10,000,000 different colors) and they provide higher resolution, but once again at the cost of something: sensitivity. Current understanding is that the 6 to 7 million cones can be divided into cones with red sensitive pigments (64%), with green sensitive pigment (32%), and with blue sensitive pigment (4%). The green and red cones are concentrated in the fovea . The blue cones have the highest sensitivity and are mostly found outside the fovea.

The missing of any of these pigments will cause color blindness, people known as daltonics. To this day nobody knows how a daltonic sees. We only know that certain lengths of waves are not perceived or are confused, for a genetic deficiency of cones.

The closure phenomenon:
When you see a photo you see an image as a whole and continuous picture. But the fact is that the photo is made of small dots, which are more obvious in low quality prints like newspapers. Your brain does not see the individual dots, unless you deliberately concentrate on them. Instead, the brain assembles the dots into a meaningful image. In other words, it sees the image as continuous. This phenomenon is called "closure".

Televisions and computer screens, as well as newspaper and magazine photos, rely on this fusion-of-small-dots capability in the brain. On a TV or computer screen, the dots are called pixels (picture elements). You can see them if you look closely, but most of the time you ignore them and instead let your brain do what it does naturally: see the overall image the small dots create.