retina display vs tft lcd free sample

Let us start with the basics first; refresh the knowledge about TN and LCD displays in general, later we will talk about TFTs (Thin Film Transistors), how they differ from regular monochrome LCD displays. Then we will go on to the ghosting effect, so we will not only discuss the technology behind the construction of the TFT, but also some phenomena, like the ghosting effect, or grayscale inversion, that are important to understand when using an LCD TFT display.

Next, we will look at different technologies of the TFT LCD displays like TN, IPS, VA, and of course about transmissive and transflective LCD displays, because TFT displays also can be transmissive and transflective. In the last part we will talk about backlight.

Let us start with a short review of the most basic liquid crystal cell, which is the TN (twisted nematic) display. On the picture above, we can see that the light can be transmit through the cell or blocked by the liquid crystal cell using voltage. If you want to learn more about monochrome LCD displays and the basics of LCD displays, follow this link.

What is a TFT LCD display and how it is different from a monochrome LCD display? TFT is called an active display. Active, means we have one or more transistors in every cell, in every pixel and in every subpixel. TFT stands for Thin Film Transistor, transistors that are very small and very thin and are built into the pixel, so they are not somewhere outside in a controller, but they are in the pixel itself. For example, in a 55-inch TV set, the TFT display contains millions of transistors in the pixels. We do not see them, because they are very small and hidden, if we zoom in, however, we can see them in every corner of each pixel, like on the picture below.

On the picture above we can see subpixels, that are basic RGB (Red, Green, Blue) colors and a black part, with the transistors and electronic circuits. We just need to know that we have pixels, and subpixels, and each subpixel has transistors. This makes the display active, and thus is called  the TFT display. TFT displays are usually color displays, but there are also monochrome TFT displays, that are active, and have transistors, but have no colors. The colors in the TFT LCD display are typically added by color filters on each subpixel. Usually the filters are RGB, but we also have RGBW (Red, Green, Blue, White) LCD displays with added subpixels without the filter (White) to make the display brighter.

Going a little bit deeper, into the TFT cell, there is a part inside well known to us from the monochrome LCD display Riverdi University lecture. We have a cell, liquid crystal, polarizers, an ITO (Indium Tin Oxide) layer for the electrodes, and additionally an electronic circuit. Usually, the electronic circuit consists of one transistor and some capacitors to sustain the pixel state when we switch the pixel OFF and ON. In a TFT LCD display the pixels are much more complicated because apart from building the liquid crystal part, we also need to build an electronic part.

That is why TFT LCD display technologies are very expensive to manufacture. If you are familiar with electronics, you know that the transistor is a kind of switch, and it allows us to switch the pixel ON and OFF. Because it is built into the pixel itself, it can be done very quickly and be very well controlled. We can control the exact state of every pixel not only the ON and OFF states, but also all the states in between. We can switch the light of the cells ON and OFF in several steps. Usually for TFT LCD displays it will be 8-bit steps per color, so we have 256 steps of brightness for every color, and every subpixel. Because we have three subpixels, we have a 24-bit color range, that means over 16 million combinations, we can, at least theoretically, show on our TFT LCD display over 16 million distinct colors using RGB pixels.

Now that we know how the TFT LCD display works, we can now learn some practical things one of which is LCD TFT ghosting. We know how the image is created, but what happens when we have the image on the screen for a prolonged time, and how to prevent it. In LCD displays we have something called LCD ghosting. We do not see it very often, but in some displays this phenomenon still exists.

If some elements of the picture i.e., your company logo is in the same place of the screen for a long period of time, for couple of weeks, months or a year, the crystals will memorize the state and later, when we change the image, we may see some ghosting of those elements. It really depends on many conditions like temperature and even the screen image that we display on the screen for longer periods of time. When you build your application, you can use some techniques to avoid it, like very rapid contrast change and of course to avoid the positioning the same image in the same position for a longer time.

You may have seen this phenomenon already as it is common in every display technology, and even companies like Apple put information on their websites, that users may encounter this phenomenon and how to fix it. It is called image ghosting or image persistence, and even Retina displays are not free of it.

Another issue present in TFT displays, especially TN LCD displays, is grayscale inversion. This is a phenomenon that changes the colors of the screen according to the viewing angle, and it is only one-sided. When buying a TFT LCD display, first we need to check what kind of technology it is. If it is an IPS display, like the Riverdi IPS display line, then we do not need to worry about the grayscale inversion because all the viewing angles will be the same and all of them will be very high, like 80, 85, or 89 degrees. But if you buy a more common or older display technology type, like the TN (twisted nematic) display, you need to think where it will be used, because one viewing angle will be out. It may be sometimes confusing, and you need to be careful as most factories define viewing direction of the screen and mistake this with the greyscale inversion side.

On the picture above, you can see further explanation of the grayscale inversion from Wikipedia. It says that some early panels and also nowadays TN displays, have grayscale inversion not necessary up-down, but it can be any angle, you need to check in the datasheet. The reason technologies like IPS (In-Plane Switching), used in the latest Riverdi displays, or VA, were developed, was to avoid this phenomenon. Also, we do not want to brag, but the Wikipedia definition references our website.

We know already that TN (twisted nematic) displays, suffer from grayscale inversion, which means the display has one viewing side, where the image color suddenly changes. It is tricky, and you need to be careful. On the picture above there is a part of the LCD TFT specification of a TN (twisted nematic) display, that has grayscale inversion, and if we go to this table, we can see the viewing angles. They are defined at 70, 70, 60 and 70 degrees, that is the maximum viewing angle, at which the user can see the image. Normally we may think that 70 degrees is better, so we will choose left and right side to be 70 degrees, and then up and down, and if we do not know the grayscale inversion phenomena, we may put our user on the bottom side which is also 70 degrees. The viewing direction will be then like a 6 o’clock direction, so we call it a 6 o’clock display. But you need to be careful! Looking at the specification, we can see that this display was defined as a 12 o’clock display, so it is best for it to be seen from a 12 o’clock direction. But we can find that the 12 o’clock has a lower viewing angle – 60 degrees. What does it mean? It means that on this side there will be no grayscale inversion. If we go to 40, 50, 60 degrees and even a little bit more, probably we will still see the image properly. Maybe with lower contrast, but the colors will not change. If we go from the bottom, from a 6 o’clock direction where we have the grayscale inversion, after 70 degrees or lower we will see a sudden color change, and of course this is something we want to avoid.

To summarize, when you buy older technology like TN and displays, which are still very popular, and Riverdi is selling them as well, you need to be careful where you put your display. If it is a handheld device, you will see the display from the bottom, but if you put it on a wall, you will see the display from the top, so you need to define it during the design phase, because later it is usually impossible or expensive to change the direction.

We will talk now about the other TFT technologies, that allow us to have wider viewing angles and more vivid colors. The most basic technology for monochrome and TFT LCD displays is twisted nematic (TN). As we already know, this kind of displays have a problem with grayscale inversion. On one side we have a higher retardation and will not get a clear image. That is why we have other technologies like VA (Vertical Alignment), where the liquid crystal is differently organized, and another variation of the TFT technology – IPS which is In-Plane Switching. The VA and IPS LCD displays do not have a problem with the viewing angles, you can see a clear image from all sides.

Apart from the different organization of the liquid crystals, we also organize subpixels a little bit differently in a VA and IPS LCD displays. When we look closer at the TN display, we will just see the subpixels with color filters. If we look at the VA or IPS display they will have subpixels of subpixels. The subpixels are divided into smaller parts. In this way we can achieve even wider viewing angles and better colors for the user, but of course, it is more complicated and more expensive to do.

The picture above presents the TN display and grayscale inversion. For IPS or VA technology there is no such effect. The picture will be the same from all the sides we look so these technologies are popular where we need wide viewing angles, and TN is popular where we don’t need that, like in monitors. Other advantages of IPS LCD displays are they give accurate colors, and wide viewing angles. What is also important in practice, in our projects, is that the IPS LCD displays are less susceptible to mechanical force. When we apply mechanical force to the screen, and have an optically bonded touch screen, we push the display as well as squeeze the cells. When we have a TN display, every push on the cell changes the image suddenly, with the IPS LCD displays with in-plane switching, different liquid crystals organization, this effect is lesser. It is not completely removed but it is much less distinct. That is another reason IPS displays are very popular for smartphones, tablets, when we have the touchscreens usually optically bonded.

If we wanted to talk about disadvantages, there is a question mark over it, as some of them may be true, some of them do not rely on real cases, what kind of display, what kind of technology is it. Sometimes the IPS displays can have higher power consumption than others, in many cases however, not. They can be more expensive, but not necessarily. The new IPS panels can cost like TN panels, but IPS panels definitely have a longer response time. Again, it is not a rule, you can make IPS panels that are very fast, faster than TN panels, but if you want the fastest possible display, probably the TN panel will be the fastest. That is why the TN technology is still popular on the gaming market. Of course, you can find a lot of discussions on the internet, which technology is better, but it really depends on what you want to achieve.

Now, let us look at the backlight types. As we see here, on the picture above, we have four distinct types of backlight possible. The most common, 95 or 99 per cent of the TFT LCD displays on the market are the transmissive LCD display type, where we need the backlight from the back. If you remember from our Monochrome LCD Displays lecture, for transmissive LCD displays you need the backlight to be always on. If you switch the backlight off, you will not see anything. The same as for monochrome LCD displays, but less popular for TFT displays, we have the transflective LCD display type. They are not popular because usually for transflective TFT displays, the colors lack in brightness, and the displays are not very practical to use. You can see the screen, but the application is limited. Some transflective LCD displays are used by military, in applications where power consumption is paramount; where you can switch the backlight off and you agree to have lower image quality but still see the image. Power consumption and saving energy is most important in some kind of applications and you can use transflective LCD displays there. The reflective type of LCD displays are almost never used in TFT. There is one technology called Low Power Reflective Displays (LPRD) that is used in TFT but it is not popular. Lastly, we have a variation of reflective displays with frontlight, where we add frontlight to the reflective display and have the image even without external light.

Just a few words about Low Power Reflective Displays (LPRD). This kind of display uses environmental light, ambient light to reflect, and produce some colors. The colors are not perfect, not perfectly clear, but this technology is becoming increasingly popular because it allows to have color displays in battery powered applications. For example, a smartwatch would be a case for that technology, or an electrical bike or scooter, where we can not only have a standard monochrome LCD display but also a TFT LCD color display without the backlight; we can see the image even in

strong sunlight and not need backlight at all. So, this kind of TFL LCD display technology is getting more and more popular when we have outdoor LCD displays and need a low power consumption.

On the picture above, we have some examples of how transmissive and reflective LCD displays work in the sunlight. If we have a simple image, like a black and white pattern, then on a transmissive LCD display, even with 1000 candela brightness, the image probably will be lower quality than for a reflective LCD display; if we have sunlight, we have very strong light reflections on the surface of the screen. We have talked about contrast in more detail in the lecture Sunlight Readable Displays. So, reflective LCD displays are a better solution for outdoor applications than transmissive LCD displays, where you need a really strong backlight, 1000 candela or more, to be really seen outdoors.

To show you how the backlight of LCD displays is built, we took the picture above. You can see the edge backlight there, where we have LEDs here on the small PCB on the edge, and we have a diffuser that distributes the light to the whole surface of LCD screen.

In addition to the backlight, we have something that is called a frontlight. It is similar to backlight, it also uses the LEDs to put the light into it, but the frontlight needs to be transparent as we have the display behind. On the example on the picture above we can see an e-paper display. The e-paper display is also a TFT display variation, but it is not LCD (liquid crystal), it is a different technology, but the back of the display is the same and it is reflective. The example you see is the Kindle 4 eBook reader. It uses an e-paper display and a frontlight as well, so you can read eBooks even during the night.

It can be argued that the display on your smartphone is its most important feature, as it is the principle way in which you interact with your device. A poor display means a poor user experience. As with all tech, it is easy to spot an under-performer, however the differences between a good display and a truly excellent display are harder to discern.

Roughly speaking there are two main types of displays used in smartphones: LCD and LED. These two base technologies have been refined and tweaked to give us AMOLED and IPS LCD. The former stands for Active Matrix Organic Light-Emitting Diode, while the latter means In-Plane Switching Liquid Crystal Display.

All of this hasn’t gone unnoticed by the marketing people, which means that plain old AMOLED or regular IPS LCD aren’t the terms used in the marketing fluff. Instead, we have Super AMOLED, Dynamic AMOLED, Super LCD, Super Retina OLED, Super Retina XDR, Infinity Display, and so on. But what’s any of that actually mean?

The LED part of AMOLED stands for Light Emitting Diode. It’s the same tech as you find on many home appliances that show that the power is on with a little red light. An LED display takes this concept, shrinks it down, and arranges the LEDs in red, green, and blue clusters to create an individual pixel.

Finally, the AM part in AMOLED stands for Active Matrix, rather than a passive matrix technology. In a passive matrix, a complex grid system is used to control individual pixels, where integrated circuits control a charge sent down each column or row. But this is rather slow and can be imprecise. Active Matrix systems attach a thin film transistor (TFT) and capacitor to each sub-pixel (i.e. red, green, or blue) LED. The upshot is that when a row and column is activated, the capacitor at the pixel can retain its charge in between refresh cycles, allowing for faster and more precise control.

The image above is a close-up shot of the AMOLED display on the Samsung Galaxy S8. The RGB triangular pattern is clearly shown. Towards the bottom of the image, the green and red LEDs are off and the blue LEDs are on only slightly. This is why AMOLED displays have deep blacks and good contrast.

Super AMOLED is a marketing term from Samsung. It means a display that incorporates the capacitive touchscreen right in the display, instead of it being a separate layer on top of the display. This makes the display thinner.

Dynamic AMOLED is another marketing term from Samsung. It denotes Samsung’s next-generation AMOLED display which includes HDR10+ certification. According to Samsung, Dynamic AMOLED also reduces the harmful blue light emitted from the display, which helps reduce eye strain and helps lessen sleep disturbances if you’re using your phone late in the day!

As for Infinity Display (or Infinity-O Display), it is more marketing from Samsung. It means “a near bezel-less, full-frontal, edge-to-edge” display. However, it is still a Super AMOLED unit.

LCD displays work with a backlight that shines through some polarizing filters, a crystal matrix, and some color filters. Liquid crystals untwist when an electric charge is applied to them, which affects the frequency of the light that can pass through. Since the crystals can be twisted to varying degrees depending on the voltage used, a display can be built when they are used with polarized panels. A grid of integrated circuits is then used to control each pixel, by sending a charge down into a specific row or column. Colors are created by the use of red, green, and blue filters, known as sub-pixels, which are then blended by varying degrees to produce different colors.

The above image is of an LCD display from a Huawei Mate 8. Notice how the pixels are made up of equally-sized sub-pixels, one for each of the colors: red, green, and blue.

Like Super AMOLED, a Super LCD display also incorporates the touchscreen. There is no “air gap” between the outer glass and the display element, which means it has similar benefits to Super AMOLED.

Samsung isn’t the only company that is good at marketing, there is another! Apple has coined the term “Retina” for its displays. The term was first used for its smartphones with the launch of the iPhone 4, as it offered a significantly greater pixel density (over 300 ppi) when compared to the iPhone 3GS. Later came Retina HD, which applies to iPhones with at least a 720p screen resolution.

All Retina and Retina HD displays on the iPhone are LCD IPS displays. However, things have changed a bit with the iPhone X as it features an AMOLED display, now marketed under the term Super Retina. It’s still an AMOLED display. It just has extra adjectives. With the launch of the iPhone 11 Pro, Apple coined the term Super Retina XDR. The XDR part means Extended Dynamic Range, as they have better contrast ratios and higher peak brightness.

Not all Retina displays use OLED. Although the MacBook Pro is marketed with a “Retina” display, as you can see from the magnified image above, it is a regular LCD, even if it uses the latest Apple silicon.

Both technologies can be used to build displays with 720p, 1080p, Quad HD, and 4K resolutions. And OEMs have made handsets that support HDR10 using both LCD and AMOLED displays. So from that point of view, there isn’t much difference between the two.

When it comes to color, we know that the blacks will be deeper and the contrast ratios higher on AMOLED displays. But, overall color accuracy can be high on both types of display.

One of the main weaknesses of AMOLED displays is the possibility of “burn-in”. This is the name given to a problem where a display suffers from permanent discoloration across parts of the panel. This may take the form of a text or image outline, fading of colors, or other noticeable patches or patterns on the display. The display still works as normal, but there’s a noticeable ghost image or discoloration that persists. It occurs as a result of the different life spans between the red, green, and blue LED sub-pixels used in OLED panels.

Blue LEDs have significantly lower luminous efficiency than red or green pixels, which means that they need to be driven at a higher current. Higher currents cause the pixels to degrade faster. Therefore, an OLED display’s color doesn’t degrade evenly, so it will eventually lean towards a red/green tint (unless the blue sub-pixel is made larger, as you can see in the first image in this post). If one part of the panel spends a lot of time displaying a blue or white image, the blue pixels in this area will degrade faster than in other areas.

The theoretical lifespan of an AMOLED display is several years, even when used for 12 hours a day. However, there is anecdotal evidence that some displays suffer from burn-in quicker than others. Displays that show signs of burn-in after only a few months should be considered defective because they certainly aren’t normal.

While owners of devices with LCD screens might congratulate themselves for picking a smartphone that is immune to burn-in, there can be a problem with LCD panels called “image retention.” Put simply, liquid crystals can develop a tendency to stay in one position when left at the same voltage for extended periods. Thankfully this phenomenon is normally temporary and can usually be reversed by allowing the liquid crystals to return to their relaxed state.

Picking a winner can be hard as there are many factors to consider, not only about the display technologies but also about the other components in a handset. For example, if you are an AMOLED fan, then would you consider a device with large storage and a good processor, but with an LCD display? The same argument works the other way for LCD fans. Generally, you’ll be fine with either display type, so just pick the handset you like.

Higher-end devices typically sport AMOLED displays and mid-range/budget devices usually use LCD. But that isn’t set in concrete as there are plenty of high-end devices that have LCD displays. With OLED production costs dropping dramatically in recent years, more and more budget options will be offering OLED panels in the future.

Companies like LG and Samsung have seen this trend coming and are rapidly expanding their OLED (and flexible OLED) production capabilities. LCD might still have a bright future in televisions and other large-panel applications, but for now, it looks like mobile will be increasingly dominated by OLED screens.

What do you think? AMOLED or LCD? What about the terms like Retina vs Infinity Display? Are they meaningful to you? Please let me know in the comments below.

The quality of a mobile phone"s display is arguably the most important factor to consider when you establish a relationship with a handset. It"s inescapable, really. Whether you"re playing a rousing game of Robot Unicorn Attack or (regrettably) drunk-dialing an ex, it"s the one interface element that you"re consistently interacting with. It"s your window to the world and your canvas for creation, and if it"s lousy, it"s going to negatively influence everything you see and do. Today, we"re delving into the world of mobile displays, where we"re aiming to entertain and edify, and hopefully save you from making regrettable decisions -- when it comes to purchasing new phones, anyway.

In this edition of Primed, we"ll be examining the different qualities and underlying technologies of several displays, starting with the ubiquitous TFT-LCD and moving through the nascent realm of glasses-free 3D and beyond. We"ll also be addressing the importance of resolution and pixel density. Finally, we"ll be scoping out a handful of upcoming technologies -- while some are thoroughly intriguing, others are just plain wacky. Go ahead... buy the ticket, take the ride, and join us after the break. It"s Primed time.

Generally speaking, two display types rule today"s mobile phones: the Liquid Crystal Display (LCD), and the Organic Light-Emitting Diode (OLED). While each technology carries a set of strengths and weaknesses, a very important distinction can be drawn between the two. The LCD uses the light modulating properties of liquid crystals (LCs), but LCs don"t emit light directly. As such, a light source is necessary for proper viewing. Conversely, the OLED uses organic compounds that illuminate when exposed to electric currents. As backlights aren"t necessary for OLEDs, they"re significantly thinner than traditional LCDs. All things equal, OLED phones should be slimmer than their LCD counterparts, but this isn"t always the case. Take for example the MEDIAS N-04C, which uses a TFT-LCD and measures 7.7mm thin, versus the Galaxy S II, which uses the latest Super AMOLED Plus display and is 8.5mm thick.

The most desirable phone displays today are variants of these two technologies. In the LCD camp, there"s the Super LCD (S-LCD) and the IPS display -- with the latter as the basis for the Retina Display and the NOVA display. Likewise, the OLED territory is filled with options such as Super AMOLED, Super AMOLED Plus and ClearBlack. We"ll discuss the important distinctions between these competing display types shortly, but first let"s develop a fundamental understanding of how these brilliant creations work and how they came to be.

The story of the LCD began in 1888 when cholesterol was extracted from carrots. Think we reached too far back? Not if you"ve ever wondered what liquid crystals are. You see, a botanist named Friedrich Reinitzer discovered this extract had two distinct boiling points and observed the molecule"s ability to transmute from liquid to a crystalline structure in the interim. Even more shocking, the cloudy substance was able to reflect circularly polarized light and rotate the light"s polarization. (This little tidbit will become important when we discuss how LCDs operate.) While liquid crystals appear throughout nature, it wasn"t until 1972 -- when 5CB (4-Cyano-4"-pentylbiphenyl) was synthesized -- that they became commercially viable. A first of its kind, 5CB was chemically stable and entered its nematic phase at room temperature. While there"s actually three phases of liquid crystals, we"re most interested in the nematic one. This describes a state where molecules flow like liquid and self-align in a thread-like helix -- and coincidentally, are easily manipulated with electricity.

Now that you"ve got a little background about liquid crystals, let"s examine how they"re used in LCDs. Let"s start by making a sandwich. As our bread, we"ll take two polarizing filters, one which polarizes light on the horizontal axis and the other on the vertical axis. If we take the slices of bread and hold them up to a light source, nothing is going to pass through. Remember when we said liquid crystals have the ability to rotate light"s polarization? Yeah, they"re a critical ingredient in our sandwich because they determine light"s passage. When nematic crystals are in their natural (or relaxed) state, they form a twisted helix. As light travels through the molecule structure, its polarization is rotated by 90 degrees and light is allowed to pass through the top filter. Conversely, when voltage is applied to the LCs, the helix is broken and light can"t escape the polarizing filters. If you"re keeping score, this is known as the twisted nematic field effect. Going back to the sandwich analogy, the nematic crystals are placed between two layers of transparent electrodes which apply voltage to the liquid crystals. It"s a rather simplistic sandwich, but it describes the fundamentals of how LCDs work. For you visual learners, Bill Hammack does an excellent job of explaining these concepts in the following video.

Now let"s apply this knowledge to the modern TFT-LCD that you"re familiar with. It"s the basis for twisted nematic (TN) and in-plane switching (IPS) displays, and both technologies rely upon the thin film transistor (TFT) for the quick response time and image clarity that we take for granted. Fundamentally, the TFT is a matrix of capacitors and transistors that address the display pixel by pixel -- although at a blistering speed. Every pixel consists of three sub-pixels -- red, green and blue -- each with its own transistor, and a layer of insulated liquid crystals are sandwiched between conductive indium tin oxide layers. Shades are made possible by delivering a partial charge to the underlying LCs, which controls the amount of light that passes through the polarizing filter, thus regulating the intensity of each sub-pixel.

The most common LCD display is based on TN technology, which has been successful due to its relatively inexpensive production costs and fast refresh rates. Many of you will remember the shadow-trail that plagued early LCDs, and faster refresh rates reduce this effect and make the displays better suited for movies and games. Unfortunately, TN displays are famous for exhibiting poor viewing angles and most aren"t capable of showing the entire 24-bit sRGB color gamut. In attempt to mimic the full range of 16.7 million colors, many screens implement a form of dithering to simulate the proper shade. Basic TN screens are hardly fantastic, but they"re also good enough to survive the day without eliciting too many complaints.

IPS displays were created to resolve the long-standing problems of poor viewing angles and color reproduction of their TN counterparts. The fundamental difference between the two technologies is that liquid crystals run parallel to the panel rather than perpendicular. This alignment allows for wider viewing angles and more uniform colors, but at a loss of brightness and contrast. Traditionally, IPS panels were significantly more expensive than TN alternatives, but recent advances have lowered the production cost and improved the brightness and contrast issues. This technology is the basis for Apple"s Retina Display and the NOVA display -- both of which are manufactured by LG.

Another technology that"s gotten plenty of airtime is the Super LCD (S-LCD), which is a display that"s manufactured by a joint-venture between Sony and Samsung. It employs an alternate method to IPS and TN that"s known as super patterned vertical alignment (S-PVA). Here, the liquid crystals have varying orientations, which help colors remain uniform when viewed from greater angles. S-LCDs also feature improved contrast ratios over traditional TN displays, which exposes a greater amount of details in dark images. Further, these displays feature dual sub-pixels that selectively illuminate based on the brightness of the screen. As you can imagine, this provides power-saving benefits, along with refined control of colors on the screen.

Now, let"s take a look at OLEDs, which are a staple of many high-end phones today. As we"ve mentioned, these displays operate without a backlight. Instead, they use electroluminescent organic compounds that emit light when they"re exposed to an electric current. The main advantages of OLEDs include deeper black levels (because there"s no backlight), enhanced contrast ratios, and excellent viewing angles, while drawbacks include reduced brightness and colors that are often over-saturated. OLED screens also suffer an awkward aging effect, where the red, green and blue sub-pixels will deteriorate and lose efficiency at different rates, which causes brightness and color consistency to worsen over time. While improvements are being made, it"s important to understand that this display technology is still relatively immature.

You"re most likely familiar with the active-matrix OLED (AMOLED), which relies on a TFT backplane to switch individual pixels on and off. Coincidentally, active-matrix displays consume significantly less power than their passive-matrix OLED (PMOLED) counterparts, which makes them particularly well-suited for mobile devices. These displays are typically manufactured by printing electroluminescent materials onto a substrate, and that relatively simplistic process suggests that OLEDs will ultimately become cheaper and easier to manufacture than LCDs. Shockingly, the most challenging step is the creation of the substrate itself, which remains a difficult and expensive endeavor. Currently, the limited supply and high demand of AMOLED screens has restricted their availability, and you"re most likely to find them in high-end smartphones.

While all screens suffer from reduced visibility in direct sunlight, the original AMOLED screens were particularly vulnerable to this drawback. To resolve this, Samsung introduced the Super AMOLED display. With this new technology, the touch sensors were integrated into the screen itself. Naturally, this allowed for a thinner display, but this also improved brightness by eliminating the extra layer. Additionally, the screen"s reflection of ambient light and power consumption were significantly reduced. While colors were now bright and vibrant -- and acceptable in direct sunlight -- the displays still couldn"t match the crispness and clarity of LCD screens, particularly with respect to text. Samsung"s PenTile matrix is to blame, which is a hallmark of its AMOLED and Super AMOLED displays. Here, a single pixel is composed of two sub-pixels, either red and green, or blue and green, and the green sub-pixel is significantly more narrow than the other two. While the scheme works fine for images because the human eye is more sensitive to green, it makes the anti-aliasing of text rather imprecise, and the end result is a bit blurry. Like Super AMOLED, Nokia"s ClearBlack display was created to make the AMOLED screen more visible in direct sunlight. This was accomplished by adding a polarized filter to the display, which allows the viewer to see through the screen"s reflection and view the images as they would appear under more ideal conditions.

In its most recent incarnation, the Super AMOLED Plus features a traditional three sub-pixels of equal proportion within one pixel, along with an increased sub-pixel count and density. Both of these measures create a display that"s much more crisp, especially when it comes to text. Further, the tighter spacing between pixels results in better visibility under direct sunlight. The new Super AMOLED Plus screens are also thinner and brighter to boot.

By now, you"ve probably had the chance of viewing a glasses-free 3D screen for yourself. Whether you think the feature is cool, gimmicky or annoying -- or, all of the above -- it"s clear that autostereoscopic displays are moving into the mainstream. If you"ve ever wondered what makes this marvel possible, today is your lucky day. First, let"s start with stereoscopic imaging itself. This merely refers to a technique that creates an illusion of depth by presenting two offset images separately to the right and left eye of the viewer. Traditionally, glasses were required to complete the effect, but a creation known as the parallax barrier has done away with that. Essentially, it"s a layer of material placed atop the screen with precision slits that allows each eye to view a different set of pixels. As you"ve likely observed (or at least read about), you"re required to position the display at a very specific angle to properly view the 3D effect. Also, because the parallax barrier effectively blocks half the light emanating from the screen, the backlight is forced to shine twice as bright -- which really kills the battery. Granted, it"s an infant as technology goes, but researchers are already making refinements. For example, MIT"s HR3D is a promising project that touts better viewing angles, brightness and battery life -- largely by increasing the number and varying the orientation of the slits.

So far, we"ve discussed the underlying technologies of mobile displays, but these options are merely one factor for consideration as you select your next phone. Screen resolution is another very important topic, as it determines the amount of content that can be displayed at any given time. Many of you are likely aware of this, but the physical size of a screen conveys nothing about the content that it can display. For example, a 4.5-inch screen with an 800 x 480 resolution actually displays less information than a 3.5-inch screen with a 960 x 640 resolution. These numbers are simply measures of the physical number of pixels positioned vertically and horizontally across the screen. Taking it a step further, the 800 x 480 screen is capable of displaying 384,000 pixels worth of information, while the 960 x 640 screen is capable of displaying 614,400 pixels worth of information. Put simply, a low-res screen simply can"t convey the same amount of content as a high-res alternative.

The most common displays today are generally based around the Wide VGA (WVGA, 800 x 480) standard, and lower-res options include Half VGA (HVGA, 480 x 320) and Quarter VGA (QVGA, 320 x 240). Another variation of this is Full Wide VGA (FWVGA, 854 x 480), which is common to Motorola"s Droid family. Quarter HD (qHD) is an up-and-comer in the mobile industry, with a 960 x 540 resolution, which is one quarter the pixel count of full 1080 HD (1920 x 1080). Lest we not forget Apple"s Retina Display, which measures 960 x 640. As you"ve seen in our reviews, we"re particularly fond of high-res screens, and HVGA really is the minimum that you should accept when purchasing a new phone.

Another component of screen resolution is pixel density, which is the total number of pixels within a physical constraint. It"s calculated in pixels per inch (ppi), which is fundamentally a measure of how tightly pixels are squeezed together. This element was somewhat of an afterthought until Apple introduced the Retina Display, but it has important ramifications for the overall crispness of text and images. While the iPhone 3GS came with a 3.5-inch screen with an HVGA resolution, the iPhone 4 kept this same screen size yet boosted its resolution to 960 x 640. The result was a massive increase in pixel density, which grew from 163ppi in the iPhone 3GS to a staggering 326ppi with the iPhone 4. Of course, these numbers are merely academic until you examine the impact that a high pixel density has upon the overall legibility of small text and clarity of images. As you"d expect, other manufacturers aren"t letting Apple have all the fun in the pixel density war, and we"re seeing particularly exciting developments from Toshiba and Samsung (more on that a bit later).

If you"re interested in calculating pixel density for yourself, you"ll need to start by knowing the display size and screen resolution. From there, you"ll need to determine the diagonal resolution of the screen with a little help from our friend Pythagoras (famous for the Pythagorean theorem). For our purposes, his equation is best expressed as follows:

Now, take the diagonal resolution (in our case, 933 pixels), and divide that by the display size (4-inches). If you"ve done the math properly, you"ll see this particular display has a pixel density of 233ppi. While most smartphones on the market today feature perfectly acceptable pixel densities, this little tidbit could come in handy if you"re looking for the clearest possible display.

Now that we"ve examined display technologies and screen resolution, let"s take a brief moment to discuss touch screens, which are crucial elements for modern smartphones. The dominant touchscreen technology is known as capacitive touch, which receives feedback from your body"s ability to conduct electricity. When you place a finger on the display, the screen"s electrostatic field becomes distorted, and the change in capacitance is registered by the underlying sensor. From there, software is used to react to your input. The beautiful part about a capacitive touchscreen is its ability to register multiple points of contact at the same time, which enables multi-touch functionality such as pinch-to-zoom.

Another type of touchscreen on the market today is known as the resistive touchscreen. It"s generally less expensive to produce and responds to physical force. While there are multiple elements to a resistive screen, the most important are two electrically conductive layers that are separated by a narrow space. When you press on the display, the two layers come into contact with one another, which registers as a change in current. Unfortunately, these added layers reduce the overall brightness of the display and increase the amount of glare reflected from the screen. You"ll generally find resistive touch screens in lower-end smartphones because they don"t support multi-touch, although a few individuals appreciate its ability to receive input from a stylus, gloved fingers or fingernails.

Hopefully we"ve given you a solid overview of the current state of mobile displays, but as you"d expect in an industry that"s rapidly evolving, there"s plenty of exciting possibilities on the horizon. Here"s a few gems that are sure to whet your palate for the future.

Ortustech (a joint-venture between Casio Computer and Toppan Printing) has developed a 4.8-inch screen with full 1080p resolution and a stunning pixel density of 458ppi. While a touchscreen isn"t in the mix, manufacturers understand the appeal of full HD, and we"re seeing the industry continually advancing upon this holy grail. Likewise, Hitachi has announced a 4.5-inch IPS display with a 1280 x 720 resolution that supports glasses-free 3D to boot. Toshiba has introduced a 4-inch contender, also at 720p, with a stunning 367ppi resolution. Samsung isn"t resting on its laurels, either, and is working on mobile displays that will push between 300 and 400ppi -- by 2015, anyway. While this announcement was specifically for tablets, we know Sammy"s smartphones are bound to benefit.

Manufacturers are finding a new take on our mobile phones being a window to the world, as transparent displays are now coming into the fray. TDK began production of a see-through OLED earlier this year, and while we"d be shocked to see this novelty crop up in smartphones, it"s sure to give some added intrigue to the feature phone segment. Whether it can actually save SMS fiends from walking into oncoming traffic is still debatable.

If you find your current smartphone far too rigid, 2012 could be quite a milestone, as Samsung is readying flexible AMOLED displays for production next year. While we plan to see smartphones with large screens that can be folded into a smaller form -- a definite improvement over current hinge-based designs -- we"d love to see an outlandish solution that fully incorporates the flexible spirit.

Take one quick look at your smartphone"s power consumption and it"s painfully obvious that the display is the primary culprit. With projects such as Mirasol and E Ink Triton leading the way, we"re hoping to see a day when color "electronic ink" becomes useful for smartphones. In addition to requiring only a fraction of the power of its illuminated brethren, these displays offer full visibility in direct sunlight. Of course, the need for a light source is a given, and current refresh rates would make for lousy gaming and video playback, but these alternatives are getting better with each new announcement. For those needing maximum battery life at all costs, these displays can"t come soon enough.

Retina Display is a brand name used by Apple for its series of IPS LCD and OLED displays that have a higher pixel density than traditional Apple displays.trademark with regard to computers and mobile devices with the United States Patent and Trademark Office and Canadian Intellectual Property Office.

The Retina display debuted in 2010 with the iPhone 4 and the iPod Touch (4th Generation), and later the iPad (3rd generation) where each screen pixel of the iPhone 3GS, iPod touch (3rd generation), iPad 2 was replaced by four smaller pixels, and the user interface scaled up to fill in the extra pixels. Apple calls this mode HiDPI mode. In simpler words, it is one logical pixel = four physical pixels. The scale factor is tripled for devices with even higher pixel densities, such as the iPhone 6 Plus and iPhone X.

The Retina display has since expanded to most Apple product lines, such as Apple Watch, iPhone, iPod Touch, iPad, iPad Mini, iPad Air, iPad Pro, MacBook, MacBook Air, MacBook Pro, iMac, and Pro Display XDR, some of which have never had a comparable non-Retina display.marketing terms to differentiate between its LCD and OLED displays having various resolutions, contrast levels, color reproduction, or refresh rates. It is known as Liquid Retina display for the iPhone XR, iPad Air 4th Generation, iPad Mini 6th Generation, iPad Pro 3rd Generation and later versions,Retina 4.5K display for the iMac.

Apple"s Retina displays are not an absolute standard for display sharpness, but vary depending on the size of the display on the device, and at what distance the user would typically be viewing the screen. Where on smaller devices with smaller displays users would view the screen at a closer distance to their eyes, the displays have more PPI (Pixels Per Inch), while on larger devices with larger displays where the user views the screen further away, the screen uses a lower PPI value. Later device versions have had additional improvements, whether an increase in the screen size (the iPhone 12 Pro Max), contrast ratio (the 12.9” iPad Pro 5th Generation, and iMac with Retina 4.5K display), and/or, more recently, PPI count (OLED iPhones); as a result, Apple uses the names “Retina HD display", "Retina 4K/5K display", “Retina 4.5K display", "Super Retina HD display", “Super Retina XDR display”, and "Liquid Retina display" for each successive version.

When introducing the iPhone 4, Steve Jobs said the number of pixels needed for a Retina display is about 300 PPI for a device held 10 to 12 inches from the eye.skinny triangle with a height equal to the viewing distance and a top angle of one degree will have a base on the device"s screen that covers 57 pixels. Any display"s viewing quality (from phone displays to huge projectors) can be described with this size-independent universal parameter. Note that the PPD parameter is not an intrinsic parameter of the display itself, unlike absolute pixel resolution (e.g. 1920×1080 pixels) or relative pixel density (e.g. 401 PPI), but is dependent on the distance between the display and the eye of the person (or lens of the device) viewing the display; moving the eye closer to the display reduces the PPD, and moving away from it increases the PPD in proportion to the distance.

In practice, thus far Apple has converted a device"s display to Retina by doubling the number of pixels in each direction, quadrupling the total resolution. This increase creates a sharper interface at the same physical dimensions. The sole exception to this has been the iPhone 6 Plus, 6S Plus, 7 Plus, and 8 Plus, which renders its display at triple the number of pixels in each direction, before down-sampling to a 1080p resolution.

The displays are manufactured worldwide by different suppliers. Currently, the iPad"s display comes from Samsung,LG DisplayJapan Display Inc.twisted nematic (TN) liquid-crystal displays (LCDs) to in-plane switching (IPS) LCDs starting with the iPhone 4 models in June 2010.

Apple markets the following devices as having a Retina display, Retina HD display, Liquid Retina display, Liquid Retina XDR display, Super Retina HD display, Super Retina XDR display or Retina 4K/5K/6K display:

Reviews of Apple devices with Retina displays have generally been positive on technical grounds, with comments describing it as a considerable improvement on earlier screens and praising Apple for driving third-party application support for high-resolution displays more effectively than on Windows.T220 and T221 had been sold in the past, they had seen little take-up due to their cost of around $8400.

Writer John Gruber suggested that the arrival of Retina displays on computers would trigger a need to redesign interfaces and designs for the new displays:

The sort of rich, data-dense information design espoused by Edward Tufte can now not only be made on the computer screen but also enjoyed on one. Regarding font choices, you not only need not choose a font optimized for rendering on screen, but should not. Fonts optimized for screen rendering look cheap on the retina MacBook Pro—sometimes downright cheesy—in the same way they do when printed in a glossy magazine.

Raymond Soneira, president of DisplayMate Technologies, has challenged Apple"s claim. He says that the physiology of the human retina is such that there must be at least 477 pixels per inch in a pixelated display for the pixels to become imperceptible to the human eye at a distance of 12 inches (305 mm).Phil Plait notes, however, that, "if you have [better than 20/20] eyesight, then at one foot away the iPhone 4S"s pixels are resolved. The picture will look pixelated. If you have average eyesight [20/20 vision], the picture will look just fine... So in my opinion, what Jobs said was fine. Soneira, while technically correct, was being picky."

Apple fan website CultOfMac hosts an article by John Brownlee"Apple"s Retina Displays are only about 33% of the way there."visual acuity in the population saying "most research suggests that normal vision is actually much better than 20/20" when in truth the majority have worse than 20/20 vision,WHO considers average vision as 20/40.presbyopia

The first smartphone following the iPhone 4 to ship with a display of a comparable pixel density was the Nokia E6, running Symbian Anna, with a resolution of 640 × 480 at a screen size of 62.5mm. This was an isolated case for the platform however, as all other Symbian-based devices had larger displays with lower resolutions. Some older Symbian smartphones, including the Nokia N80 and N90, featured a 2.1 inch display at 259 ppi, which was one of the sharpest at the time. The first Android smartphones with the same display - Meizu M9 was launched a few months later in beginning of 2011. In October of the same year Galaxy Nexus was announced, which had a display with a better resolution. By 2013 the 300+ ppimark was found on midrange phones such as the Moto G.Samsung Galaxy S4 and HTC One (M8) had 1080p (FHD) screens around 5-inches for a 400+ PPI which surpassed the Retina density on the iPhone 5. The second major redesign of the iPhone, the iPhone 6, has a 1334 × 750 resolution on a 4.7-inch screen, while rivals such as the Samsung Galaxy S6 have a QHD display of 2560 × 1440 resolution, close to four times the number of pixels found in the iPhone 6, giving the S6 a 577 PPI that is almost twice that of the iPhone 6"s 326 PPI.

The larger iPhone 6 Plus features a "Retina HD display", which is a 5.5-inch 1080p screen with 401 PPI. Aside from resolution, all generations of iPhone Retina displays receive high ratings for other aspects such as brightness and color accuracy, compared to those of contemporary smartphones, while some Android devices such as the LG G3 have sacrificed screen quality and battery life for high resolution. Ars Technica suggested the "superfluousness of so many flagship phone features—the move from 720p to 1080p to 1440p and beyond...things are all nice to have, but you’d be hard-pressed to argue that any of them are essential".

TFT stands for thin-film transistor and is used with LCD to improve image quality over older digital display technologies. Each pixel on a TFT LCD has its own transistor on the glass itself, which offers greater control over the images and colors that it renders.

TFT is also an abbreviation for other technical terms including time from transmission, text fix test, Trinitron flat tube, and trivial file transfer protocol.

Since the transistors in a TFT LCD screen are so small, the technology offers the added benefit of requiring less power. However, while TFT LCDs can deliver sharp images, they also tend to offer relatively poor viewing angles. The result is that TFT LCDs look best when viewed head-on, but viewing images from the side is often difficult.

TFT LCDs are found on low-end smartphones as well as basic cell phones. The technology is also used on TVs, handheld video game systems, computer monitors, and GPS navigation systems.

All the pixels on a TFT screen are configured in a row-and-column format, and each pixel is attached to an amorphous silicon transistor that rests directly on the glass panel. This allows each pixel to be given a charge and for the charge to be kept even when the screen is refreshed to produce a new image.

With this type of setup, the state of a particular pixel is being actively maintained even while other pixels are being used. This is why TFT LCDs are considered active matrix displays (as opposed to a passive matrix displays).

Lots of smartphone manufacturers use IPS-LCD (Super LCD), which provides wider viewing angles and richer colors, but newer phones feature displays that utilize OLED or Super-AMOLED technology. For example, Samsung"s flagship smartphones boast OLED panels, while most of Apple"s iPhones and iPads come equipped with an IPS-LCD. Super LCD and Super-AMOLED have their own pros and cons, but they both far exceed the capabilities of TFT LCD technology.

Several display types are currently used in smartphones, and the most popular touchscreen displays are LCD, TFT, IPS, OLED, AMOLED, Super AMOLED and Retina.

Touchscreen LCDs fall into two categories: resistive or capacitive. Resistive touchscreens react to pressure from a finger, fingernail, stylus or other hard objects. The lack of multi-touch functionality, however, has limited resistive displays mostly to lower-end devices. Capacitive touchscreens, meanwhile, support multi-touch and are designed to react to the touch of a bare finger. This technology can be found in most mid-range to high-end smartphone and tablet displays, and users generally appreciate the smooth swiping motions and intuitive interface.

Thin Film Transistor, aka TFT LCD displays are superior to previous LCDs, delivering higher resolution and better image quality. On the other hand, TFT displays deliver poor visibility in bright light and have narrow viewing angles. This technology is typically found in budget phones or low-end smartphones.

In Plane Switching, aka IPS LCD technology delivers better viewing angles compared with TFT, while also drawing less power to allow for more battery efficiency. IPS displays typically cost more to make, however, and that"s why they"re typically used in higher-quality smartphones that come with a price to match. On the plus side, IPS is the most advanced type of LCD display tech and delivers notably wider viewing angles, extremely accurate color reproduction.

Organic Light-Emitting Diode, aka OLED displays involve a carbon-based material placed in between two conductive sheets, with class plates encasings at the top and bottom. OLED display technology delivers accurate colors, good viewing angles and a rapid response, while also allowing for lightweight and compact designs.

AMOLED, meanwhile, stands for Active-Matrix Organic Light-Emitting Diode. AMOLED and Super AMOLED technology is more expensive and is used only in high-end flagships, offering a number of benefits. This display technology delivers bright and vivid colors, great battery efficiency and wide viewing angles, while also allowing for lighter displays.

LCD and AMOLED are the most commonly used display types in current smartphones and tablets. LCDs are backlit, battery efficient, very bright, and extremely precise in displaying the entire color spectrum, which contributed to its wide popularity. AMOLED, however, eliminates the need for backlighting because each sub-pixel creates its own light. Compared to LCD, AMOLED may at times deliver less accurate colors and less visibility in direct sunlight.

Retina displays are also well-known on the market, partly because Apple is behind this technology. Apple developed and deployed Retina displays in a number of its devices, using this technology in conjunction with capacitive touchscreens. Retina displays have stirred lots of waves over the past few years due to their sharp resolution, clear and bright colors, and great accuracy.

Lastly, haptic touchscreens have their place as well on the display market. Nokia and BlackBerry have used haptic technology for some of their enterprise-oriented touchscreen smartphones and generally received positive reviews. Haptic technology basically provides tactile feedback on touch, thus confirming that it registered the touch input. Based on reviews, haptic technology can notably improve user performance and accuracy when typing on a touchscreen.

In addition to the various types of display technology, many smartphones also use Gorilla Glass protection to increase their durability. Gorilla Glass is a tough, protective glass sheet that"s highly resistant to damage. Used on many smartphones from Samsung, Motorola, Nokia and others, Gorilla Glass can provide good protection against scratches, bumps and drops, thus increasing the device"s durability.

Knowing the different types of display technology available can help users make an informed decision when purchasing a smartphone, choosing the one that best suits their needs, budgets and preferences.

2020 Update: NVIDIA and ASUS now has a long-term road map to 1000 Hz displays by the 2030s! Contacts at NVIDIA and vendors has confirmed this article is scientifically accurate.

For those new to Blur Busters, I am the co-author of a peer reviewed conference paper (along with researchers from NOKIA, NIST.gov and Keltek) on successfully photographing display motion blur which several websites have now adopted, including RTINGS, TFTCentral, SWEclockers, HDTVtest, etc.  The most prominent site of these, RTING.com, credits me (here, here, and in the Credit Screen of the below YouTube) for my invention in inexpensively photographing display motion blur.

Also, we were the world’s first consumer website to test a genuine true-480 Hz display (no fake Hz). We had to invent new motion tests to test 480 Hz.

For this optical effect, view this on LCD instead of CRT or plasma. If using motion blur reduction (e.g. ULMB, BFI, or interpolation), turn that feature off temporarily for this animation demo. Another great TestUFO animation is TestUFO Persistence-of-Vision.

Warning for flicker-sensitive people: There are other animations further down on this page that utilize flicker to demonstrate scientific principles of display motion blur behaviour.

These are two very different pixel response measurements, as seen in the GtG versus MPRT FAQ. There are many 60Hz displays with <1ms GtG (e.g. OLED) but has 16.7ms MPRT (lots of motion blur).

Persistence (in milliseconds) is also known scientifically as “MPRT” in research papers (Google Scholar search). Quoted as a number, MPRT100% and persistence often mean the same thing by modern virtual reality scientists and newer display engineers. For example, Chief Scientist at Oculus, Michael Abrash, wrote a famous blog article that use the “persistence” terminology.

This is because fast GtG doesn’t always mean fast MPRT. Back in 2013, I wrote “Why Does OLED Have Motion Blur?” when people were surprised by OLED motion blur despite OLED’s fast pixel response. This is due to the “sample-and-hold” effect, otherwise known as display persistence.

Over the years, we did many tests (beginning with 60Hz vs 120Hz vs LightBoost in 2013, and most recently, becoming the world’s first website to test 480Hz in 2017).

Motion blur on modern digital displays are reduced via strobing or black frame insertion (BFI) to lower persistence. Many LCD gaming monitors use strobe backlights (such as ULMB) that flicker at the same frequency of the refresh rate, in order to reduce motion blur.

Many newer displays, especially OLED displays and modern TN gaming monitors, have the majority of their GtG pixel transitions complete in a tiny fraction of a refresh cycle. This makes GtG an insignificant percentage of MPRT. Such displays exhibit behaviour that closely follows Blur Buster’s Law.

It is guaranteed that there can’t be less motion blur than this number, no matter how good your vision is. This is the motion blur you get when GtG pixel response is instant (0ms). In the real world, motion blur can be worse than this, due to finite pixel response. This is before any additional blur is added, such as GtG limitations (additional smearing/ghosting) or display source limitations (camera blur or slow camera shutter) or human vision limitations (natural motion blurring).

It is an immutable constant (like the speed of light) where you can’t get less display motion blur than this number. Blur Busters Law assumes perfect squarewave persistence, where GtG is 0ms at both leading and trailing edge. So any display with GtG above 0 is always worse than Blur Busters Law.

This is the Blur Busters simplification of the MPRT formula found in this scientific paper. We use MPRT100% instead of MPRT90% (in the scientific paper). A120Hz ideal sample-and-hold display with 0ms GtG has identical motion blur (MPRT100%= 8.333ms) as a 1/120sec photo shutterfor the same physical panning velocity of full frame rate material.

We preferMPRT100%at Blur Bustersfor math simplicity and to match human-perceived motion blur on modern ultrafast sample-and-hold displays. Whereupon 240fps at 240Hz perceives exactly the same motion blur as a 1/240sec camera shutter photograph.And it is also easier for blogs to calculate from TestUFO motion tests.

Assumptions: The exact Blur Busters Law minimum is achieved only if pixel transitions are fully square-wave (0ms GtG) on fully-sharp sources (e.g. VR, computer graphics). Actual MPRT numbers can be higher.Slow GtG pixel response will increase numbers above the Blur Busters Law guaranteed