Between all the display resolutions, refresh rates and other screen technologies available today, shopping for monitors is more difficult than ever. While this article won’t cover all the angles involved with buying a new LCD, it will explain the differences between panel types including IPS, TN and VA, as well as which one is best suited for your intended purpose – whether gaming, graphic design or watching movies.
Note that although we won’t delve deep into many monitor specifications here, such as the ever-pressing question of whether you should buy a 60Hz or 144Hz monitor, we plan to cover that subject (and more) in future articles here at Voltcave.
What is a Liquid Crystal Display (LCD)?
Before explaining the core differences between IPS, TN and other LCD panel technologies, it’s worth covering what an LCD is on a fundamental level. Short for “liquid crystal display,” LCDs are comprised of several different layers that generally include:
- A backlight or mirror as the bottom or back layer that shines light through the rest of the layers.
- Two polarizing filters that allow certain waves of light through (Video and GIF examples below).
- A liquid crystal layer between the two polarizing filters that helps control the waves of light.
- Pixels with subpixels of red, green and blue filters that colorize the light as it passes through.
Each type of LCD – IPS, TN and so on – takes a different approach to manipulating light as it passes through those layers. As a result, certain types of panels are better at specific applications. While each one can generally boast about a given set of specifications, none of them are perfect across the board and they all come with trade-offs.
IPS vs. TN: A Few Technical Details
Among the various approaches to developing LCDs, IPS and TN panels are by far the most common. A majority of the monitors you find on the market will fall into these two categories and it’s likely that you’ll wind up purchasing an LCD based on one of these technologies. Before spending your money, it’s worth understanding the core differences that make each one more or less suitable for different purposes.
Without going into painstaking detail about every approach to developing LCDs, here’s a brief technical overview of IPS vs. TN panels:
TN (twisted nematic) – Twisted nematic LCDs have their two polarizing filters arranged in an opposite direction (90 degrees) from one another, while the liquid crystal is arranged in a “twisted” helix fashion and then begins to straighten when voltage is applied. As light passes through this helix shape light waves are twisted and accordingly allowed to pass through the outer polarizing filter. When the crystal layer is straightened, light can’t pass through the outer polarizing filters. Here’s that animated GIF we mentioned earlier to help you visualize this process:
IPS (in-plane switching) – Instead of having the polarizing filters arranged in opposite directions as in TN LCDs, IPS panels have their filters going in the same direction (horizontally) so that when the liquid crystal layer is in its resting helix shape, light can’t pass through because the light waves are twisted in a way that isn’t compatible with the outer filter. Instead, voltage must be applied to straighten the crystal layer and to begin allowing light through – essentially the opposite way that TN panels are designed, which allows light through until voltage is applied.
IPS vs. TN Specifications: Pros & Cons
Given the difference in design choices, there are many pros and cons when using an IPS vs. TN panel. Here’s a quick breakdown of various LCD specifications and a quick explanation of whether IPS or TN panels are the most suitable choice if that spec is a high priority for your needs:
Viewing angles – TN panels have poor image quality when they are being viewed with the monitor turned on an angle. When you aren’t viewing TN displays straight on, they begin to look washed out and the image is increasingly difficult to discern as the angle is increased. This shortcoming was one of the incentives behind developing IPS panels back in the late 80s and early 90s.
IPS panels have considerably broader viewing angles. TN panels tend to have somewhere in the realm of 170° horizontal and 160° vertical viewing angles while IPS displays commonly push that to 178° horizontal and vertical, allowing for the image to be viewed with minimal distortion from nearly 180°.
Color depth – Likewise, TN panels typically fall short when it comes to accurately producing the broadest array of colors, while IPS panels excel in this category. A large portion of the TN monitors sold today only have 6-bit panels, limiting the amount of colors that can be produced compared to most IPS monitors which tout 8-bit panels. It’s possible to find some TN monitors with 8-bit colors, though it’s unlikely that you’ll find any TN panels with 10-bit colors and this is available on premium IPS models.
Color gamut – Whereas bit depth tells you how many colors a monitor can produce (an 8-bit display can show 16.8 million colors), color gamut tells you the precise range of those colors – or in other words, which colors can be displayed. Without throwing a bunch of acronyms at you (sRGB, DCI-P3 etc.), suffice it to say that IPS panels are known for supporting a broader array of colors while TN panels are known for being much less adequate when it comes to producing a wide gamut of colors.
Response time – The response time of a monitor measures how quickly a pixel can change colors from white to black (or black to white) or from one shade of gray to another. While TN panels may not have the best viewing angles or color reproduction, they boast faster response times than IPS panels. TN panels commonly provide response times of 1ms or 2ms, while IPS panels are generally upwards of 4-5ms, though some exceptions are available if you’re willing to pay a premium.
Refresh rate – Whereas response times measure the rate at which each pixel can change between colors, the refresh rate of a monitor marks the rate at which it can draw a new image. For example, a 60Hz monitor can refresh its image 60 times per second.
TN panels also have the highest refresh rates on offer, with 144Hz and 240Hz displays being widely marketed. It’s most common to find IPS panels with refresh rates of 60Hz, though 144Hz IPS monitors are available and becoming less rare.
Contrast – Though you can find IPS displays that exceed the contrast ratio of TN panels, both panel technologies tend to list a contrast around 1,000:1. If having a high contrast image is a priority for you over all the other specifications here, you may want to consider shopping for a monitor based on VA panel tech, which we’ll touch on briefly after this section.
Power consumption – Few people purchase monitors based on the amount of power they consume, but it may be a concern for some folks, especially if we’re talking about an office with dozens or hundreds of displays. While IPS panels tend to be a better choice for professional environments because of their superior image quality and color accuracy, they do typically draw more power.
Price – Apart from their high response rate, the strongest selling point of TN panels is their affordability. While IPS monitors are much less expensive than they were a decade ago, TN-based LCDs are still considerably cheaper.
Where Do VA Panels Fit Into All This?
VA (vertical alignment) panels are the least common display technology that you are likely to come across when shopping for a new monitor. Instead of having its liquid crystals aligned vertically, VA displays have their liquid crystals positioned vertically so that they are perpendicular to the panel instead of being parallel as in TN and IPS panels.
The big selling point of this approach to LCDs is that it allows for tremendous contrast ratios. While IPS and TN panels typically have contrast ratios around 1,000:1, VA-based monitors tout considerably more than that at 2,000:1, 3,000:1 and upwards of 4,500:1 on the pricier models.
This allows for extremely bright whites and deep blacks, but it takes the display that much longer to change between colors and thus results in slow response times that are 4-5ms at best and many are slower than that. Folks who have played games on VA panels report that fast-paced imagery can produce noticeable blurring/ghosting.
Along with having a phenomenal contrast ratio, VA panels have viewing angles and color reproduction that sits somewhere between the capabilities of most TN and IPS panels. If you’re sold on the idea of having an uber high contrast ratio and aren’t scared off by the slow response times, VA panels are probably worth considering.
Gaming vs. Design vs. Movies
Playing games – TN panels are typically preferred by gamers for having less issues with motion blur thanks to their response times of 2ms or less and the wide availability of 144Hz and 240Hz models. Although TN panels are the safe bet for playing games, it should be said that IPS monitors with relatively quick response times can be found, as can models with 144Hz refresh rates, and these are adequate for playing fast paced games. Also, games that don’t necessarily require such a high response time could benefit from the superior image quality of an IPS panel.
Graphic design – While you can certainly Photoshop an image on a TN panel, anyone who does image/video editing and design on a professional level would be better off with the greater range of colors and reproduction accuracy that comes with investing in an IPS monitor. If you aren’t concerned about fast-paced gaming and you can afford the difference in quality, an IPS panel is probably the best overall choice for everyday computing. Note that most smartphones use IPS panels for their superior image quality and viewing angles.
Watching videos – Both panel technologies have their place when it comes to watching videos – it just depends on what you’re watching. Folks who enjoy fast-paced sports may benefit from the from the high response time and refresh rate of a TN panel to avoid motion blurring, while those who tend to partake in more cinematic experiences are probably better off with the better image quality of IPS or contrast ratio of a VA panel.
Final Thoughts: No Monitor is Perfect
As with most PC components, there’s a distinct compromise between specifications and pricing that will influence your purchasing decision. In the case of LCD monitors, that decision largely boils down to whether you prefer the faster performance and lower price of a TN panel, or the superior image quality of an IPS or VA panel. Assuming you can afford the premium over TN panels, most PC shoppers are probably best off considering a 144Hz IPS display for the best of both worlds: relatively snappy performance with a high quality image.