Flat panel televisions are gaining popularity with consumers at such a rapid pace that flat panel televisions have almost phased out old CRT TVs.with the passage of time, as the popularity of lcd flat panel televisions is growing with the consumers, their prices are fast delcining and their quality is improving simultaneously,every body desires to replace his old CRT TV set with flat panel lcd television.Flat panel lcd television looks very desireable,however,befor youre decide to buy a flat panel lcd television,there are certain parameters and technical specifications that you must consider.
Here are a few tips that may be helpful to you in buying a flat panel lcd television:
1. Screen Size : You need to figure out the screen size of the LCD TV appropriate for you.The screen size of an LCD TV is measured diagonally.The screen size of LCD TV appropriate for you may be evaluated by two ways,i.e.,either by considering your viewing distance from LCD TV or by considering the image size of the image produced by LCD TV.Screen size of LCD TV based on viewing distance may be figured out by multiplying your viewing distance from LCD TV (in feet) by four to get the screen size of LCD TV ( in inches) that is suitable for you.For example if your like to watch the TV by sitting at a distance of 10 feet (120 inches) then the appropriate screen size of LCD TV for your is 40 inches (10*4 = 40).
An LCD TV (wide screen,16:9 aspect ratio), when compared with the CRT TV (4:3 aspect ratio) of same diagonal screen size, is actually smaller than CRT TV.For example,if you compare a 32 inch wide-screen LCD TV with 32 inch CRT TV,the LCD TV is 11% smaller than CRT TV and image produced by LCD TV is 33% smaller in area as compared with the image produced by CRT TV.Therefore,to make up for this discrepency of LCD TV and to maintain the same image size for LCD TV,while watching TV, as is prodeced by CRT TV,you should buy an LCD TV which is 1.22 times bigger than the CRT TV.For example,if you had a 32 inch CRT TV and you want to maintain the same image size for the LCD TV that you intend to buy then you need to buy an LCD TV with screen size of approximately 40 inches.An important factor that you should keep in mind while choosing an LCD by considering image size is that you should also figure out the optimal viewing distance from your LCD TV by dividing the screen size (in inches) by four to get the viewing distance in feet.For example for a 40 inch screen size of LCD TV the viewig distance would be 10 feet (40/4 = 10 feet).
2. Gamma or Saturation: Gamma is an important charateristic of LCD TV which greatly affects the quality and clarity of the images being displayed by the TV.Gamma of an LCD TV is the measure of light emittd by the pixels that have been lit.With low value of gamma,the image displayed by the LCD will appear dim.Dark areas of the image being displayed by the LCD will appear too dark to clearly display the details of the image.with low value of gamma dark areas of image would appear rather appear black. Too high value of gamma is not good either.with high value of gamma the image being displayed by the LCD will appear too bright to be clearly visible.Bright areas of image would appear almost white and it would be almost impossible to differentiate pale colors from white color.Gamma is a characteristic that is totally different from brightness and contrast.
An easy approach to figure out how good gamma of an LCD TV is to critically ispesct the image being displayed by the LCD that has both dark and bright areas.For this purpose you can inspect the image that has been shot in bright daylight.On a good quality LCD TV,the dark areas of image will appear almost black rather than gray and bight areas of image will clearly display the true color of the area instead of appearing white.For example,for a good LCD TV with good gamma,the light blue color of sky should not appear white and dark brown color of doors should not appear black.
Documentary films telecast by channels like discovery,national geographic and animal planet are full of images that contain multiple and bright colors,which may serve as a benchmark to test the gamma of the LCD TV.To check for the gamma of your LCD TV, while you watch a documentary film telecast by these channels,you should look for birghtness and strength of colors of blue sky,red flowers and green grass.You should note that on an LCD TV with good gamma these colours should not appear overly bright or washed out.
3. Brightness and Contrast: Brightness and contrast are important charatceristics of an LCD TV.These characteristics greatly affect the quality and sharpness of the images displayed by the LCD TV.These two parameters show different characteristics of the image displayed by the LCD TV.Brightness means how bright the shadows in the image displayed by LCD are while contrast means how bright the highlights in the image displayed by LCD are.For example if two circles are being displayed in the image produced by the LCD TV,one circle is light in color while other circle is dark in color.The brightness setting of LCD TV will affect the dark colored circle while the contrast setting will affcet the light colored circle.If both the brightness and contrast settings of an LCD TV have been set to their minimum levels,the screen will appear purely black in color.
while buying an LCD TV you should carefully check the brightness and contrast of your LCD TV.Dealers usually set the brightness of LCD TV to the highest level which may be decpetive,especially for a layperson who lacks deep technical knowledge about characteristics of an good LCD TV.While checking the brightness and contarst of the LCD TV,you should adjsut these settings of LCD TV to almost 50% of their maximum levels and if with these settings the picture quality looks good to you then this LCD TV may be a good choice for you.
A good technique to check for the quality of contrast settings of LCD TV is to watch a movie which contains scenes with black and white colors.while watching the black and white scenes in such a movie you should critically observe the quality of black and white colors.In an LCD TV with good quality of contrast the dark areas should appear black or very close to black color rather than appearing gery.Similarly white areas should appear milky white instead of appearing florescent white.
4. Hue-Shift: Hue-shift is a defect in picture quality of a TV caused by shift in colors of image displayed by the TV towards a certain color.A TV with this defect would display images with pronounced effects of a certain tint like red,green or blue.This defect was more pronounced in early models of CTR TVs,however with evolution of technology this defect was rectified and pciture quality of CRT Televisons improved remarkably.LCD TVs despite their superior circuitry and digital technology are not free of this defect either.This defect of hue-shift in images displayed by LCD TV becomes more pronounced while watching cable or satellite TV channels.However,this defect is less visible in images displayed by the TV while watching DVDs on the LCD TV.A good LCD TV should be free of this defect.To check for this defect in LCD TV you should note the skin tone of the people in images being displayed by the LCD TV,if skin tone of people look natural to you,while watching a movie or some other program on LCD TV then your LCD TV is free of defect caused by hue-shift and it does not have imbalance of saturation either.
5. Refresh Rate: An LCD TV is a flat panel television,which employes Liquid Crystal Technology.The LCD TV panel is made up of a matrix of liquid crystals in which a liquid crystal serves as a switch to either block the light from passing through it or allow the light to pass through it.LCD crystals do not generate their own light,they require an external source of light like LED or florescent bulb for making the image produced by the LCD TV visible to the viewer.
In a conventional CRT TV images on the screen of TV are generated by means of scanning by an electron beam.This mechanism is not used in LCD TV.Unlike conventional CRT TV,the pixels of an LCD TV,controlled by liquid crystals, are switched on and off at a particular refresh rate.The entire image is displayed a particular number of times in a second,which refers to refresh rate of the image,which is expressed in terms of Hertz (Hz).Typical image refresh rates for LCD TV are 30Hz,60Hz or 120 Hz.If the image referesh rate of LCD TV is low then it may result in blurring or flickering of the image displayed by the TV.A good LCD TV should have an image referesh rate high enough not to let the displayed image burr or flicker.
To check how good the image refresh rate of LCD TV is,you should switch the TV to financial or news channel and should carefully observe the bottom of the image for scrolling news.A good LCD TV should not present blurry text in scrolling news at the bottom of image being displayed.
6. Audio Output: Unlike conventional CRT TV, LCD technology utilized in LCD TVs has greatly the reduced the weight and bulkiness of Television.This is why unlike a conevntional CRT TV,an LCD TV may be hung on the wall.But downside to this reduction in bulkiness and weight is that this inovation in television technology has deprived the LCD TV of the physical depth necessary to accomodate large sized and high quality speakers to produce loud sound.Due to the limitations posed by phsyical dimensions,the LCD TVs are usually equipped with small sized speakers which are only good enough for watching news and documentary channels.But these tiny speakers cannot produce loud sound good enough for enjoying movies or music videos.Therefore,if you want to enjoy watching movies or music videos with high fidelity sound, on your LCD TV,you need to hookup your LCD TV with external sound amplifier or home theatre system.So,while buying an LCD TV,make sure that the LCD TV is equipped with interface for hooking up LCD TV to external sound amplifiers.
7. Interfacing with computer : If the LCD TV that you intend to buy is equipped with the feature to be interfaced with computer then it is really a very useful feature.I think this a very important feature of an LCD TV that you must take into consideration.DVD palyers available in market do not support all video formats.Some of the video files in video formats like WMV and MKV etc. are not played by some DVD players.On the other hand a computer can play almost all video and audio file formats.So if your LCD TV may be interfaced with computer then you can enjoy movies and music videos on big screen of your LCD TV in a variety of video formats.
8. Pixel Defects: LCD TV is a new technology as compared with CRT TV.So this technology is not free of defects and is still far from perfection.Depending upon the size of screen,the image produced by the LCD TV is composed of millions of pixels or picture elements.Each pixel serves as a blind or switch which may be shut or opened by application of voltage.The quality of the image produced by the LCD TV depends upon proper functioning of these individual pixels.Sometimes defects arise in LCD TV at individual pixels level and indvidual pixels fail to function properly which results in pixel defects.
Defects that may arise in pixels of LCD are mainly of two types i.e.,Full-Pixel Defect and Sub-Pixel Defect.It may be noted if three colors red,green and blue are combined together this results in white color.Similarly in case of LCD displays, a white colored pixel composed of three sub-pixels i.e., red,green and blue colored pixels.A defect developed in any one or two of three sub-pixels is called sub-pixel defect.If all the three sub-pixels that produce white colored pixel are defective then it results in full-pixel defect.
A good LCD TV should ideally be free of pixel defects,however,it is practiacally quite difficult to produce LCD TV which is 100% free of pixel defects.So if some pixel defects exist in the LCD TV that do not make any noticeable deterioation in quality of the image produced by the LCD TV,then it is acceptable.
9. HD Ready vs. Full HD : LCD Televisions that are commonly available in market are wide screen having 16:9 aspect ratio and are either HD-Ready or Full-D. HD-Ready and Full-HD TVs basically differ in resolution of the images produced by these two types of TVs.A Full-HD TV produces an image having resoluation of about 2 millions pixels (1920 x 1080 pixels),while an HD-Ready TV produces an image which has a resolution of about 1 million pixels(1366 x 768 pixels).
An HD-Ready TV despite its capability to be interfaced with high-definition source like Sony Play-station 3,Blue-ray Disc player,XBox 360 and HD Set-top Box etc.,is not necessarily equipped with the capabitility to display a full high-defition image in its true sense.The resolution of the image displayed by an HD-Ready TV is much less than necessary for a true high-definition image.So the image displayed by the HD-Ready TV when connected with high-definition source would not be good enough due to having lower number of pixels to display all the details for the image to be truly high-definition.
Unlike an HD-Ready TV a Full-HD is fully capable of displaying a high-definition image in its true sense.However,it should be noted that Televisions that are being shipped to the market are mostly capable of displaying true high definition videos but the broadcasters are still not ready to broadcast true high-definition videos.
So,as far as the question of buying HD-Ready or Full-HD TV is concerned,you should obviously go for better option i.e.,Full-HD TV,so that you may enjoy not only the next generation high resolution videos from high definition sources other than broadcasters and also,in future, your TV may be able to play high definition videos when broadcasters in your country are ready for high-definition video broadcasting.
10. LCD TV Inputs: The types of video input interfaces that the LCD TV is equipped with are an important parameter of LCD TV that need to be considered critically while buying an LCD TV.If this feature of LCD TV is overlooked by you while buying the TV,this may make you regret after you have purchased the TV.
Video inputs are actually the interfaces by which other units feed their video signals into the LCD TV for display.Video inputs may be classified into two categoris i.e., standard technology and high-definition.
while buying an LCD TV make sure that the TV is equipped with Standard-Definition inputs like S-Video and Composite Video inputs as well as High-Definition Inputs like HDMI (High-Definition Multimedia Interface),DVI (Digital Visual Interface) and Component Video so that it may be interfaced with a variety of video sources.
I hope these tips may prove helpful to a layperson in deciding to buy a good LCD TV.
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