LG 32LG40 LCD HDTV Review

32 in.

The 32LG40 is a 32-inch set with a basic feature set and a built-in DVD player.

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Blacks & Whites

Blacks & Whites Summary
{{article.attachments['LG-32LG40-vanity.jpg']}} • Poor black level. • Average peak brightness. • Bad contrast ratio, but great tunnel contrast and white falloff. • Uniform screen. • Average greyscale gamma and resolution scaling.
{{article.attachments['tvi-prev.jpg']}} Calibration Page 4 of 16 Color Accuracy {{article.attachments['tvi-next.jpg']}}

Black Level*(4.42)*

Low black levels are both important for picture quality and, for the majority of LCD TVs, hard to achieve. This is because LCDs use a series of backlights. It's hard to create a low black level when you start with a bunch of lights blazing. Without low black levels, that spooky cave scene in your movie will just look off, with bottomless pits looking like blotches of grey.

The 32LG40 had a very weak blackl level. The deepest black it was capable of 0.52 cd/m2, which is about twice as bright as our average. This is bad; the blacks all look unnaturally bright. Not only does this make dark scenes appear washed out, but it hurts the TV's contrast ratio. The JVC LT-32P679's lowest black was 0.12 cd/m2, which is significantly lower than the 32LG40's. For black levels, 0.1 cd/m2 is a significant difference, let alone 0.4 cd/m2. The Samsung LN32A450 was capable of 0.14 cd/m2, which is similarly gigantic leap forward. The Panasonic Viera TH-46PZ8OU blew the 32LG40 away, however, with its absurdly low black level: 0.06 cd/m2.

What does this mean for the home viewer? A loss of detail among dark colors. On a TV with a very low black level, you could look at a night scene and notice details in a dark area. On the 32LG40, that area might just blur into a swath of dark grey.


Peak Brightness*(7.12)*

An LCD's backlight is the reason it typically has low black levels, but it's also the reason why it excels at peak brightness levels. Brightness is important for combating external light, primarily. If your TV is near a window, or if it's around several light sources, a low peak brightness will mean all the surrounding light will wash out the picture. If you want your TV to be safe from these malifluous wash-out effects, you should look for a brightness of 250 cd/m2 or higher.

LCDs might have an advantage here, but the 32LG40 really didn't impress us with its peak brightness level. We were only able to get 212.61 cd/m2 out of it. Our average score so far is about 290. The Samsung LN32A450, another LCD, was able to output 308.94 cd/m2.

Plasma TVs typically output much less, however. The Panasonic Viera TH-46PZ8OU, for example, could only manage 61.45 cd/m2




Contrast refers to the ratio of the white level to the black level. Higher contrasts mean there's more differentiation between light and dark. With a high contrast, dark areas in a bright room will pop as opposed to blending into each other blandly.

Unfortunately, the latter case is more true for the 32LG40 than the former. The TV had a contrast ratio of 408.87:1, which is significantly below our current average, which is 1680:1. This is one of the worst contrast ratios we've gotten to date. Other LCDs, like the Samsung LN32A450, are capable of over 2000:1 ratios. The Panasonic Viera TH-46PZ8OU, a plasma, also out-performed the 32LG40 with its contrast ratio of 1024:1.

A note on our contrast test: the reason the ratios above are very different than the manufacturer-stated ratios is because manufacturers tend to fib. Well, it might not be a fib, but a typical trick is to measure the ratio between the brightest possible output you can configure and the darkest possible screen you can configure (which typically involves turning the backlight off). Since these two extremes gererally require a bevvy of settings to be set in totally opposite ways, we disregard this number; it's not a contrast you'd be able to witness on the screen. Also, many of these settings would ruin the overall picture quality. Our figures, on the other hand, are much more representative of what you will actually experience through normal use.


Tunnel Contrast*(9.82)*

The TV's contrast involves measuring an all white screen and an all black screen separately. Since whites can wash out darks and darks can dampen whites when both are on screen at the same time, we also perform a tunnel contrast test. This test measures the luminance of a black rectangle that is surrounded by white. We start with the rectangle taking up 90% of the screen, then shrink it until it only takes up about 10%. Ideally, the size of the rectangle should not affect its luminance. Some TVs, however, won't be able to maintain the depth of the black rectangle as it surrounded by more and more white. The graph below describes the TV's tunnel contrast. The percentage of white filling up the screen is at the bottom and the luminance of the black rectangle is on the side. 


LCDs do well on this test, and the 32LG40 is no exception.  The luminance of the blacks don't increase even when surrounded by a lot of white. Even though the TV doesn't have a very high overall contrast, when the whitest whites and darkest darks appear next to each other, you won't lose much of either.

White Falloff*(9.99)*

White falloff is the same as tunnel contrast, only it uses a white rectangle surrounded by a black border. Again, we measure the luminance levels as the white box shrinks and the area of the surrounding black increases. We are again looking for changes in the rectangle's luminance levels; there shouldn't be any.


As alluded to by our introductory sentence, we didn't see any white falloff issues with the 32LG40. The luminance of each white remained unchanged, regardless of what percentage of the screen was white and what percentage is black.


Uniformity is somewhat self-explanatory: it refers to the uniformity of white and black levels across the screen. If the center of the TV is the only place you get deep black levels, or if the whites have shadowy blotches in random areas, the TV has poor uniformity.

The 32LG40 had good uniformity overall. The white screen only showed slight darkness at its corners. Likewise, the black screen showed some white shadows towards its corners. While we definitely noticed them, they only extended out two inches or so; some TVs cast white shadows that extend six inches or more away from the corner.

Greyscale Gamma*(6.8)*

To understand Gamma, you must first understand a simple fact about the human perception: we tend to hear/see/sense things logarythmically. For example, if a TV had a white screen that displayed 100 cd/m2 was suddenly bumped up to 200 cd/m2, you would notice that the screen looked twice as bright. Once you were at the 200 cd/m2 luminescence, however, to notice the same difference you'd have to bump the TV up to 400 cd/m2. Likewise, you'd next need the screen to hit 800 cd/m2 in order to say it had doubled again. The difference between the 100 and 200 cd/m2 output is far more significant than the difference between a 400 and 500 cd/m2 output. For this reason, a TV with a good greyscale gamma, when graphed, will result in a curve rather than a straight line.

This lesson aside, the 32LG40 had a textbook average greyscale gamma. The curve below is slightly curved, to meet the demands of our human sensory inputs, but not quite curved enough.



The main issues with the graph above are that, when you get towards the intense ends, the graph doesn't progress in that 2:1 ratio we talked about. This means you won't see as much difference between two different grades of white or black.

If you prefer straight lines, the graph below is for you. The following is plotted on a logarythmic scale. This means that the increments on the graph itself increase logarythmically as opposed to the graph. The result: an apparently straight line, or at least it should be. The light blue line represents the ideal line the graph should be following. It stays somewhat close to this line, but manages to stray a bit at times.


Resolution Scaling*(6.43)*

The 32LG40 has a 720p display. This isn't the current highest definition, 1080p, but it's close. Sure, the TV does fine in its native resolution, but what if you want to play something that's a lower or (gasp) higher resolution? In this section we find out, by letting the 32LG40 upscale and downscale some images.


The resolution 480p is a step up from standard definition. You'll get this via a digital output, such as from a high-end DVD player, or some cable boxes. Since the 32LG40 is a 720p set, some would assume it would have no issues playing a 480p source. If you are one such person, prepare to be a bit disappointed, but not outright distraught: the 32LG40 is a little subpar when playing non-720p material. With 480p input, we had issues reading most small fonts because the letters would meld together like someone took a magnifying glass to them on a sunny day. Also, patters of alternating black and white lines often turned to a gradient, which is indicative of a processing issue. You'll also run into some minor overscanning; unless something particularly riveting is happinging on that outer 2% of the screen, it'll mainly serve as an annoyance.


This resolution is like HD Lite. The 'i' stands for 'interlaced,' meaning the TV breaks the display into a series of lines, then alternates showing the evens and odds so the final product looks like a full picture to our slow human eyes. Again, a slightly subpar performance. We noticed the issues with the text smudging together again, only this time it was slightly worse. The issue of gradients forming where alternative black and white lines should have been also reared its head. Keeping in mind that the 32LG40 is performing above and beyond its native resolution, however, it wasn't particularly awful.


A resolution of 1080p is full HD. You don't have to deal with interlacing as in the above: all 1080 lines of pixels will be visible at all times for your viewing pleasure. We ran into identical errors on 1080p as we did with 1080i, which is to say, it was slightly worse than the upscaled 480p, but not terribly so.

Our editors review and recommend products to help you buy the stuff you need. If you make a purchase by clicking one of our links, we may earn a small share of the revenue. Our picks and opinions are independent from any business incentives.


  1. Tour & Design
  2. Calibration
  3. Blacks & Whites
  4. Color Accuracy
  5. Motion
  6. Viewing Effects
  7. Remote Control
  8. Audio
  9. Connectivity
  10. Menus & Interface
  11. Formats & Media
  12. Power Consumption
  13. Conclusion & Comparisons
  14. Series Comparison
Our editors review and recommend products to help you buy the stuff you need. If you make a purchase by clicking one of our links, we may earn a small share of the revenue. Our picks and opinions are independent from any business incentives.
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Our editors review and recommend products to help you buy the stuff you need. If you make a purchase by clicking one of our links, we may earn a small share of the revenue. Our picks and opinions are independent from any business incentives.
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