TV buying guide

Whether you want a new bedroom set or a massive home-theatre centerpiece, our CNET editors' guide gives you the full picture on shopping for a new TV.

4. Judging picture quality

Judging picture quality

The most difficult thing to judge when shopping for a TV is how good the picture looks. Good is a subjective term, so relying on the judgment of reviewers (such as CNET) may not get you exactly what you want. Then again, many reviewers scoff at the kinds of pictures that impress TV shoppers in the store. In this section, we'll offer some tips on become a more discerning viewer and what separates good pictures from the rest.

Image quality factors: The wall of tubes | Features that enhance picture quality | Calibration

Wall of tubes
Most electronics stores show their televisions on a big wall, fed by the same video signal split a hundred times. Although bright lights, suspect salespeople, and a lack of remote controls will probably make any picture-quality judgment difficult, here are a few things to look for on the wall.
  • Don't fall for brightness. Almost every television on the sales floor is set to the brightest picture settings, so try to get the salesperson to reduce the controls of the TVs you're comparing. You want the pictures -- not necessarily the controls -- to be roughly equal in brightness, contrast and colour.
  • Go out of the light. Few living rooms are as well lit as the sales floor, so see if the salesperson can reduce the amount of light shining on the picture. If nothing else, try to shade the screen if light is shining directly on it.
  • BYO DVD. Monsters Inc If you have a DVD that you're familiar with, see if you can use it instead of the TV signal that's normally shown. Aside from digital signal, which your store may or may not get, DVD provides the best picture a television can display, so it makes for a good reference from which to judge.
  • Try all the picture modes. Many sets come with numerous picture presets, such as Movie and Sports, that radically affect how the image appears. After you peruse the manually adjusted pictures, try the different presets and modes to see which ones look best.
Features that enhance picture quality

Normal analog TVs, as opposed to digital TVs, have just a few factors that affect picture quality. Look for these features or characteristics and disregard other features that sound good on the surface but in reality are just marketing ploys. Naturally, there are other important factors we can't cover here, but this should get you started.

    • Comb filter. If a television does not have a comb filter, its resolution will be limited to about half the full potential of DVD. Most sets with comb filters can provide all of the resolution of DVD. The types of comb filters you'll see advertised, in order of lower to higher quality, include two-line, three-line, digital, and 3D YC varieties. They provide incremental improvements in performance, especially in reducing rainbows that can appear in fine detail, such as a talking head's suit coat. Comb filters affect only composite-video or RF connections (see Inputs and outputs).
    • Colour-temperature settings. Many televisions have presets for colour temperature, which is basically the colour of grey. A neutral grey is ideal, but most TVs have an extremely blue grey to make the picture brighter in the store. TVs with colour-temperature presets allow you to choose the colour of grey; generally, you'll want the reddest or lowest setting available.
    Grayscale
    • Colour decoder. Most TVs' colour decoders are set to be too red to counteract the blue colour temperature described above. TV makers don't advertise accurate colour decoders, so you'll have to judge for yourself or trust a reviewer. In the store, look for pale skin tones that don't appear too flushed and reds that don't bleed into other colours or otherwise seem more intense than the rest of the palette.
    Colour
    • Geometry and convergence. Most TVs get bumped around in shipping, so it pays to check convergence before you take yours home -- or at least before the warranty expires. Look toward the edges of the screen, preferably with graphics or other straight lines (a news organisation's crawling ticker works great), and see if the lines are actually straight. To check convergence, look at the corners with white material, preferably lines again, and see if faint halos of colour surround the white.
Calibration
Digital Video Essentials Alternatively, you can use a calibration DVD to help you adjust the television. These discs, such as Ovation Software's Avia, Joe Kane's Digital Video Essentials, and Sound & Vision's Home Theater Tune-Up, show you how to optimise your set within the limits of the standard user-accessible menus.
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Metricity posted a comment   

What's with the centimetres? The metric standard uses millimetres. http://measurement.gov.au.

 

Sim posted a comment   

I can't find a list of plasma, LCD sizes hight width and depth, I know the depth will vary but finding anything on this one would think would be easy...not so!

 

STIMPY posted a comment   

i say we use our new system to measure tvs you should use pixels to the power of 10 or even squids how many squids your tv is .... yes squids >.>

 

cybergod posted a comment   

Hmmm. Inches vs centimetres? Have a bloody look around. Retailers keep switching from calling it XX" or ""cm.I personally am totally confused. Even Harvey Norman use both and it is simply stupid.

 

Cal posted a comment   

I agree with Pieter.

 

Pieter posted a comment   

We use centimeters because we use the metric system. Only silly old USA uses inches. Catch up. It's been years and years...

 

jmbau posted a comment   

Really helpful info. Thanks a heap - this helped me sort my way through a maze of somewhat confusing gobbledegook and understand what is important and what I should be looking for. Appreciate it!

 

rodcat posted a comment   

what's with the centimetres ? why not use inches ?




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