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There's been a steady growth of Ultra HD and 4k resolutions over the last year or so in the monitor market. Initial screens were in a large format, but super high resolutions have started to enter smaller screen sizes as well. It's important before we start, to understand that this increase in resolution needs to be thought of differently to monitors of the past. It's not really about providing more screen real estate and working space unless the size of the screen is also increased significantly as well. It's about providing sharper scaled images on the screen, with a similar overall desktop real estate to work with. Rather than us go in to it in a lot of detail here, we would really recommend a read of Eizo's very useful article about this subject. That will hopefully make the whole thing much clearer.

We have with us at the moment a 27" sized screen from ViewSonic, their new flagship model in their Professional VP series. The VP2780-4K is designed for CAD/Cam, photography, architecture and video editing according to their website and its highlights are an Ultra HD 3840 x 2160 resolution, IPS panel and 10-bit colour depth. It also carries a few advanced features including factory calibration, a 14-bit 3D LUT and MultiPicture (PiP and PbP) functionality. Note that although this is a professional range monitor it sticks to a normal sRGB gamut which is more commonly needed than wide gamut and avoids unnecessary additional cost. In fact if you look back at the previous 27" VP models you will see the VP2710-LED in 2012 had a standard gamut and 1440p resolution, the VP2772 in 2014 moved to wide gamut at 1440p, and now the VP2780-4K reverts to standard gamut again but this time with Ultra HD resolution.

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Specifications and Features

The following table gives detailed information about the specs of the screen:

Monitor Specifications


27"WS (68.47 cm)

Panel Coating

Light AG coating

Aspect Ratio



1x DisplayPort 1.2a

1x Mini DisplayPort 1.2a

1x HDMI 2.0

2x HDMI 1.4 / MHL 2.0


3840 x 2160

Pixel Pitch

0.156 mm

Design colour

All matte black design

Response Time

5ms G2G


Tilt, 150mm height, swivel and rotate

Static Contrast Ratio


Dynamic Contrast Ratio

20 million:1

VESA Compatible

Yes, 100 x 100


350 cd/m2


Power cable and brick, DisplayPort, HDMI, MHL and USB cables. Factory calibration report

Viewing Angles

178 / 178

Panel Technology

LG.Display AH-IPS


8.36Kg (with stand)

Backlight Technology


Physical Dimensions

(WxHxD) with stand:
642.7 x 469.7x 347.8 mm

Colour Depth

1.07b (8-bit + AFRC)

Refresh Rate


Special Features

4x USB 3.0 ports (charging supported), factory calibration, PiP and PbP support, headphone jack

Colour Gamut

Standard gamut
100% sRGB, 80% Adobe RGB, 99% EBU, 75% NTSC

The VP2780-4K offers a decent range of connectivity options with DisplayPort, Mini DisplayPort, HDMI 2.0 and 2x HDMI 1.4 / MHL 2.0 provided. The digital interfaces are HDCP certified for encrypted content and the video cables are provided in the box for HDMI, MHL and DP. The DisplayPort and HDMI 2.0 connections can support the full 3840 x 2160 resolution at 60Hz refresh rate, with the other HDMI inputs only supporting that resolution at 30Hz maximum.

The screen has an external power supply brick which is provided of course. There is a headphone output connection although no integrated speakers on this model. There are also 4x USB 3.0 ports on this model, but no other extras like ambient light sensors or motion sensors.

Below is a summary of the features and connections of the screen:


Yes / No


Yes / No

Tilt adjust


Height adjust


Swivel adjust


Rotate adjust


VESA compliant


USB 2.0 Ports


USB 3.0 Ports

Audio connection

Card Reader

HDCP Support

Ambient Light Sensor

MHL Support

Human Motion Sensor

Integrated Speakers

Touch Screen

PiP / PbP

Factory Calibration

Blur Reduction Mode

Hardware calibration


Uniformity correction


Design and Ergonomics


Above: front views of the screen. Click for larger versions

The VP2780-4K comes in an all black design, with matte black plastics used for the bezel, stand and base. The bezel measures ~21mm around all edges and looks quite thin as a result. There is a subtle grey ViewSonic logo in the middle of the bottom bezel, and grey OSD control labels in the bottom right hand corner. Other than that there are no further writings or logos on the front of the screen.

Above: rear view of the screen. Click for larger version

The back of the screen is again a matte black plastic. The stand connects in the middle at the back and can be unscrewed if you want for VESA 100 compliant mounting options. There are some cable tidy clips on the back of the stand as well as you can see above.

Above: side profile view. Click for larger version

From the side you can see the actual panel has a thin profile, thanks to the use of W-LED backlighting and an external power supply. The stand however creates a much deeper footprint. It is 347.8mm (nearly 35cm) deep so you do need a fairly deep desk to accommodate the screen, without it being very close to you. With the stand being very wide and deep it does provide a very sturdy base for the screen though and from the front does not look overly chunky.

Above: view of the base. Click for larger version

The base of the stand is shown above. We did feel the stand gives the screen a slightly industrial and sturdy feel, as opposed to being focused on sleek design. ViewSonic have kept this stand design for this range for a long time though and it is a case of function over design perhaps. Not a criticism really, more an observation.

Above: full tilt range. Click for larger versions

The screen offers a full range of ergonomic adjustments. The tilt adjustment is smooth and easy to move and offers a nice wide range as well as shown above.

Above: full height adjustment range. Click for larger versions

Height adjustment is smooth but a little stiff to operate, but again provides a very good range. At the lowest setting the bottom edge of the screen is 8cm from the edge of the desk, and at the highest setting it is 23cm. This gives you a total 15cm (150mm) adjustment range as advertised.

Above: rotated view. Click for larger version

The side to side swivel and rotation function are both smooth but quite stiff to operate. Nice to see a full range of adjustments offered from the stand here.

A summary of the screens ergonomic adjustments is shown below:




Ease of Use








Quite Stiff




Quite Stiff




Quite Stiff


Good range of adjustments and easy enough to move. Sturdy stand and base.

The materials were of good standard and the design and build quality felt robust and sturdy. There was no audible noise from the screen, even when conducting specific tests which can often identify buzzing issues. The whole screen remained reasonably cool during prolonged use.

Above: interface connections on the back of the screen. Click for larger version

The back of the screen features all the connections along the underside of the central section. There is, from left to right, USB upstream, 2x USB 3.0 downstream, MHL 2, MHL 1, HDMI 2.0, DisplayPort, Mini DisplayPort, headphone port and the power connection.


OSD Menu

Above: OSD control buttons on the bottom edge of the screen. Click for larger version

The OSD menu is accessed and controlled through a series of 5 touch-sensitive buttons located on the front of the screen in the bottom right hand corner (including the power on/off button).

There is quick access to the input selection, volume control and saveable user modes via the 2, down arrow and up arrow buttons.

Pressing the 1 button brings up the main OSD menu as shown above. This is split in to 8 sections.

The first section gives you access to the brightness and contrast controls. We've already looked at the second and third sections which are also available via the quick launch controls (input selection and audio control). Therefore the second photo above is of the fourth section, the 'color adjust' menu. Here you can switch between a series of preset colour temperature modes.

The fifth section gives you information about the screen and there aren't any settings to change here. The sixth section however is the 'manual image adjust' menu and has lots of things to play with. There is the dynamic contrast ratio option if you wanted to use that. There's also control over the response time setting which we will test later on in the review. 

The gamma control in this section allows you to adjust the gamma level if you need to. There is also a selection of settings for the PiP / PbP option in the 'multi picture' option.

Elsewhere in the same 'manual image adjust' section of the menu you can switch between the 'view modes' as shown. The seventh section of the menu (right hand image) allows you to control various things related mainly to the OSD itself. The last section of the main menu is the 'memory recall' option for resetting the screen.

There is also a hidden factory menu on the screen if you hold the 1 button while powering on the screen. Pressing 1 to then bring up the main menu you will see a small "F" at the top. If you scroll up to this and enter, there is another menu as shown below.


Power Consumption

We carried out our normal tests to establish its power consumption of the display, as compared with the specified values from the manufacturer:

State and Brightness Setting

Manufacturer Spec (W)

Measured Power Usage (W)

Default (100%)



Calibrated (8%)



Maximum Brightness (100%)



Minimum Brightness (0%)






We tested this ourselves and found that out of the box the screen used 42.9W at the default 100% brightness setting. Once calibrated to a far more comfortable brightness level the power consumption was only 20.5W. In standby it used only 0.5W. We have plotted these results below compared with other screens we have tested. You will notice the calibrated power consumption is very similar to other W-LED backlit displays. Wide gamut LED backlights (e.g. ViewSonic VP2772) use a bit more, and CCFL units (e.g. Eizo SX2762W and NEC PA271W) use quite a considerable amount more.

Panel and Backlighting

Panel Manufacturer


Colour Palette

1.07 billion

Panel Technology


Colour Depth

8-bit + AFRC

Panel Module


Colour space

Standard gamut

Backlighting Type


Colour space coverage (%)

75% NTSC, 80% Adobe RGB, 100% sRGB, 99% EBU

Panel Part and Colour Depth

The screen features an LG.Display LM270WR2 AH-IPS panel which is capable of producing 1.07 billion colours. The panel offers an 8-bit colour depth with an additional Advanced Frame Rate Control (8-bit + AFRC) stage added at a panel level. Keep in mind whether this is practically useable and whether you're ever going to truly use that colour depth. You need to have a full 10-bit end to end workflow to take advantage of it which is still quite expensive to achieve and rare in the market, certainly for your average user. This includes relevant applications and graphics cards as well, so to many people this 10-bit support might be irrelevant. The part is confirmed when accessing the factory OSD menu as shown below:

Screen Coating

The screen coating is a light anti-glare (AG) offering. It isn't a semi-glossy coating, but it is light as seen on other modern IPS type panels. Thankfully it isn't a heavily grainy coating like some old IPS panels feature. It retains its anti-glare properties to avoid too many unwanted reflections of a full glossy coating, but does not produce an too grainy or dirty an image that some thicker AG coatings can. There were no cross-hatching patterns visible on the coating even when you inspect it closely.

Backlight Type and Colour Gamut

The screen uses a White-LED (W-LED) backlight unit which has become the norm in today's market. This helps reduce power consumption compared with older generation CCFL backlight units and brings about some environmental benefits as well. The W-LED unit offers a standard colour gamut which is approximately equal to the sRGB colour space. Studying the detailed spec provided by ViewSonic states that there is a colour space coverage of 75% NTSC, 80% Adobe RGB, 99% EBU and 100% sRGB. Anyone wanting to work with wider colour spaces would need to consider wide gamut CCFL screens or the newer range of GB-r-LED type displays available now. If you want to read more about colour spaces and gamut then please have a read of our detailed article.

Backlight Dimming and Flicker

We tested the screen to establish the methods used to control backlight dimming. Our in depth article talks in more details about a common method used for this which is called Pulse Width Modulation (PWM). This in itself gives cause for concern to some users who have experienced eye strain, headaches and other symptoms as a result of the flickering backlight caused by this technology. We use a photosensor + oscilloscope system to measure backlight dimming control with a high level of accuracy and ease. These tests allow us to establish

1) Whether PWM is being used to control the backlight
2) The frequency and other characteristics at which this operates, if it is used
3) Whether a flicker may be introduced or potentially noticeable at certain settings

If PWM is used for backlight dimming, the higher the frequency, the less likely you are to see artefacts and flicker. The duty cycle (the time for which the backlight is on) is also important and the shorter the duty cycle, the more potential there is that you may see flicker. The other factor which can influence flicker is the amplitude of the PWM, measuring the difference in brightness output between the 'on' and 'off' states. Please remember that not every user would notice a flicker from a backlight using PWM, but it is something to be wary of. It is also a hard thing to quantify as it is very subjective when talking about whether a user may or may not experience the side effects.

100%                                                  50%                                                  0%

Above scale = 1 horizontal grid = 5ms

At all brightness settings a direct current (DC) method is used for backlight dimming, instead of any PWM method. As a result, the screen is flicker free as advertised.

Pulse Width Modulation Used


Cycling Frequency


Possible Flicker at


100% Brightness


50% Brightness


0% Brightness


For an up to date list of all flicker-free (PWM free) monitors please see our Flicker Free Monitor Database.


Contrast Stability and Brightness

We wanted to see how much variance there was in the screens contrast as we adjusted the monitor setting for brightness. In theory, brightness and contrast are two independent parameters, and good contrast is a requirement regardless of the brightness adjustment. Unfortunately, such is not always the case in practice. We recorded the screens luminance and black depth at various OSD brightness settings, and calculated the contrast ratio from there. Graphics card settings were left at default with no ICC profile or calibration active. Tests were made using an X-rite i1 Display Pro colorimeter. It should be noted that we used the BasICColor calibration software here to record these, and so luminance at default settings may vary a little from the LaCie Blue Eye Pro report.

OSD Brightness


Black Point (cd/m2)

Contrast Ratio
( x:1)














































Total Luminance Adjustment Range (cd/m2)


Brightness OSD setting controls backlight?

Total Black Point Adjustment Range (cd/m2)


Average Static Contrast Ratio


PWM Free? 

Recommended OSD setting for 120 cd/m2


The brightness control gave us a very good range of adjustment. At the top end the maximum luminance reached 411 cd/m2 which was extremely high, and quite a bit more even than the specified maximum brightness (370 cd/m2) from the manufacturer. There was a decent 319 cd/m2 adjustment range in total, and so at the minimum setting you could reach down to a fairly low luminance of 93 cd/m2. This should be adequate for most people wanting to work in darkened room conditions with lower ambient light, although it could have done with being a little lower we felt. We'd gladly have sacrificed some range at the higher end. A setting of only 8 in the OSD menu should return you a luminance of around 120 cd/m2 at default settings. It should be noted that the brightness regulation is controlled without the need for Pulse Width Modulation, using a Direct Current (DC) method for all brightness settings between 100 and 0% and so the screen is flicker free.

We have plotted the luminance trend on the graph above. The screen behaves as it should in this regard, with a reduction in the luminance output of the screen controlled by the reduction in the OSD brightness setting. This is a linear relationship as you can see from the graph.

The average contrast ratio of the screen was very good for an IPS panel with an average of 1063:1. This was nice and stable across the brightness adjustment range as shown above.

Testing Methodology

An important thing to consider for most users is how a screen will perform out of the box and with some basic manual adjustments. Since most users won't have access to hardware colorimeter tools, it is important to understand how the screen is going to perform in terms of colour accuracy for the average user.

We restored our graphics card to default settings and disabled any previously active ICC profiles and gamma corrections. The screen was tested at default factory settings using an X-rite i1 Pro Spectrophotometer (not to be confused with the i1 Display Pro colorimeter) combined with LaCie's Blue Eye Pro software suite. An X-rite i1 Display Pro colorimeter was also used to verify the black point and contrast ratio since the i1 Pro spectrophotometer is less reliable at the darker end.

Targets for these tests are as follows:

  • CIE Diagram - validates the colour space covered by the monitors backlighting in a 2D view, with the black triangle representing the displays gamut, and other reference colour spaces shown for comparison

  • Gamma - we aim for 2.2 which is the default for computer monitors

  • Colour temperature / white point - we aim for 6500k which is the temperature of daylight

  • Luminance - we aim for 120 cd/m2, which is the recommended luminance for LCD monitors in normal lighting conditions

  • Black depth - we aim for as low as possible to maximise shadow detail and to offer us the best contrast ratio

  • Contrast ratio - we aim for as high as possible. Any dynamic contrast ratio controls are turned off here if present

  • dE average / maximum - as low as possible. If DeltaE >3, the color displayed is significantly different from the theoretical one, meaning that the difference will be perceptible to the viewer. If DeltaE <2, LaCie considers the calibration a success; there remains a slight difference, but it is barely undetectable. If DeltaE < 1, the color fidelity is excellent.

Default Performance and Setup

The VP2780-4K carries a factory calibration in three of the preset modes. Those being native, sRGB and EBU. A custom report is provided in the box for the specific unit you have, confirming the test measurements and results. Targets are applied for the gamma curve (2.2), white point (6500k) and dE colour accuracy (<2). A copy of the reports provided with our sample are shown below for reference:

Default settings of the screen were as follows:

Monitor OSD Option

Default Settings





Colour Adjust mode






ViewSonic VP2780-4K - Default Settings, Native Mode



Default Settings,
Native Mode

luminance (cd/m2)


Black Point (cd/m2)


Contrast Ratio



Initially out of the box the screen was set in the default 'native' colour adjust mode. At this setting you do not have access to the RGB levels. Brightness was set at an eye-scorching 100% by default. The screen looked very bright out of the box, colours felt pretty well balanced and the colour temperature also felt good.


The CIE diagram on the left of the image confirms that the monitors colour gamut (black triangle) is roughly equal to the sRGB colour space. There is some minor over-coverage in blue shades, and some minor under-coverage in greens and reds, but not by anything significant. Default gamma was recorded at 2.2 average, leaving it with only a 1% deviance from the target which was very good news. White point was measured at 6406k being very close to the target of 6500k with a minor 1% deviance.



Luminance was recorded at an extremely bright 426 cd/m2 which is far too high for prolonged general use. Thankfully you can change the brightness setting to whatever you like without impacting other areas of the setup. The black depth at this high brightness level was 0.39 cd/m2, giving us a very good static contrast ratio (for an IPS-type panel) of 1082:1. Colour accuracy was mostly pretty good out of the box, with average dE at 2.5. Blue and green shades were a problem where dE ranged up to 6.5 maximum. When testing the screen with colour gradients there was some slight gradation evident as you will see from most monitors in darker tones, but no banding evident.


We also measured the screen out of the box in the sRGB (factory calibrated) mode:

Monitor OSD Option

Default Settings





Colour Adjust mode






ViewSonic VP2780-4K - Default Settings, sRGB Mode


Default Settings,
sRGB Mode

luminance (cd/m2)


Black Point (cd/m2)


Contrast Ratio



When you switch to the sRGB preset mode the luminance of the screen drops very noticeably. You can see from the OSD menu that the brightness has been reduced to 25, although you can still change it if you want to. The default setup remains largely similar to the native mode, with gamma and white point being only a minor 1 - 2% out from the targets, and dE being basically the same as before. The main change here was the luminance, now measured at only 54 cd/m2. This was lower than we had reached during our initial brightness range measurements in the native preset mode, even though the brightness control in the OSD was still at 25 here (and not 0). The contrast ratio had been reduced as well, now measured at only 574:1. In this preset mode there seems to be an additional digital white level adjustment applied to bring the luminance down much lower. However, this crushes contrast ratio which we don't really want. As a result, we don't feel this mode should be used. Stick to the native mode, or calibrate the user mode if you want and keep a much better contrast ratio.





We used the X-rite i1 Pro spectrophotometer combined with the LaCie Blue Eye Pro software package to achieve these results and reports. An X-rite i1 Display Pro colorimeter was used to validate the black depth and contrast ratios due to lower end limitations of the i1 Pro device.


Monitor OSD Option

Calibrated Settings





Colour Adjust mode

User Color


92, 92, 100

ViewSonic VP2780-4K  - Calibrated Settings



Calibrated Settings

luminance (cd/m2)


Black Point (cd/m2)


Contrast Ratio



We changed to the 'user define' colour temperature mode which gave us access to the RGB channels, allowing us to adjust the white point at the hardware level. These OSD changes allowed us to obtain an optimum hardware starting point and setup before software level changes would be made at the graphics card level. We left the  LaCie software to calibrate to "max" brightness which would just retain the luminance of whatever brightness we'd set the screen to, and would not in any way try and alter the luminance at the graphics card level, which can reduce contrast ratio. These adjustments before profiling the screen would help preserve tonal values and limit banding issues. After this we let the software carry out the LUT adjustments and create an ICC profile.



Average gamma was now corrected to 2.2 average, correcting the very minor 1% deviance we'd seen out of the box. The white point was now also corrected to 6513k, again correcting the minor 1% deviance from before. Luminance had been corrected nicely to 122 cd/m2 and this left us a black depth of 0.12 cd/m2 and maintained a very good static contrast ratio (for an IPS-type panel) of 1002:1. Colour accuracy of the resulting profile was excellent, with dE average of 0.3 and maximum of 0.6. LaCie would consider colour fidelity to be excellent overall. Testing the screen with various colour gradients showed mostly smooth transitions. There was some slight gradation in darker tones but no banding introduced due to the adjustments to the graphics card LUT from the profilation of the screen. You can use our settings and try our calibrated ICC profile if you wish, which are available in our ICC profile database. Keep in mind that results will vary from one screen to another and from one computer / graphics card to another.




Calibration Performance Comparisons


The comparisons made in this section try to give you a better view of how each screen performs, particularly out of the box which is what is going to matter to most consumers. When comparing the default factory settings for each monitor it is important to take into account several measurement areas - gamma, white point and colour accuracy. There's no point having a low dE colour accuracy figure if the gamma curve is way off for instance. A good factory calibration requires all 3 to be well set up. We have deliberately not included luminance in this comparison since this is normally far too high by default on every screen. However, that is very easily controlled through the brightness setting (on most screens) and should not impact the other areas being measured anyway. It is easy enough to obtain a suitable luminance for your working conditions and individual preferences, but a reliable factory setup in gamma, white point and colour accuracy is important and not as easy to change accurately without a calibration tool.


From these comparisons we can also compare the calibrated colour accuracy, black depth and contrast ratio. After a calibration the gamma, white point and luminance should all be at their desired targets.



Default setup of the screen out of the box was good thanks to the factory calibration, with gamma and white point being only a very minor 1% away from their targets. The contrast ratio was also strong at 1082:1 for an IPS panel. It was far too bright though but thankfully that's easy enough to lower with a simple change to the brightness control. We would have liked a slightly better dE if we're honest, but it still provided good levels of colour accuracy which should be more than adequate for most normal users.




The display was strong when it came to black depth and contrast ratio for an IPS-type panel. With a calibrated contrast ratio of 1002:1 it was comparable to some of the better screens using this kind of panel technology. Anything over 1000:1 would be very good for an IPS panel really at the moment. It was not quite as high as some models like the Dell U2515H (1138:1) which holds the record for an IPS contrast ratio. Of course it can't compete with VA panel types which can reach over 2000:1 easily, and commonly up to 3000:1, even close to 5000:1 in some cases like the Philips BDM4065UC.


Viewing Angles

Above: Viewing angles shown from front and side, and  from above and below. Click for larger image

Viewing angles of the screen were very good as you would expect from an IPS-type panel. Horizontally there was very little colour tone shift until wide angles past about 45. A slight darkening of the image occurred horizontally from wider angles as you can see above as the contrast shifted slighting. Contrast shifts were more noticeable in the vertical field with the image appearing more pale. A slight pink hue was also introduced vertically. The screen offered the wide viewing angles of IPS technology and was free from the restrictive fields of view of TN Film panels, especially in the vertical plane. It was also free of the off-centre contrast shift you see from VA panels and a lot of the quite obvious gamma and colour tone shift you see from some of the modern VA panel types. All as expected really from a modern IPS-type panel.

Above: View of an all black screen from the side. Click for larger version

On a black image there is a pale white / blue glow when viewed from an angle, commonly referred to as IPS-glow. This kind of glow is common on most IPS-type panels and can be distracting to some users. A lot of panels show a more obvious silvery white glow than this (e.g. see the recent Asus MG279Q using an IPS-type panel) and so on the VP2780-4K it is not quite as obvious day to day. It is still there though so something to be aware of if you work with a lot of dark content. If you view dark content from a normal head-on viewing position, you can actually see this glow as your eyes look towards the edges of the screen if the screen is of a large size.

Panel Uniformity

We wanted to test here how uniform the brightness was across the screen, as well as identify any leakage from the backlight in dark lighting conditions. Measurements of the luminance were taken at 35 points across the panel on a pure white background. The measurements for luminance were taken using BasICColor's calibration software package, combined with an X-rite i1 Display Pro colorimeter with a central point on the screen calibrated to 120 cd/m2. The below uniformity diagram shows the difference, as a percentage, between the measurement recorded at each point on the screen, as compared with the central reference point.

It is worth noting that panel uniformity can vary from one screen to another, and can depend on manufacturing lines, screen transport and other local factors. This is only a guide of the uniformity of the sample screen we have for review.

Uniformity of Luminance

The luminance uniformity of the screen was reasonable overall with the four corners showing some drop in luminance by about -20% in the most extreme cases. The upper and central regions were closer to the calibrated central point of the screen. Around 51% of the screen was within a 10% deviance of the centrally calibrated point.

Backlight Leakage

Above: All black screen in a darkened room. Click for larger version

As usual we also tested the screen with an all black image and in a darkened room. A camera was used to capture the result. The camera showed there was some clouding in the upper right hand corner but nothing very noticeable at all, and certainly not something you'd see during normal uses.


General and Office Application

The VP2780-4K feature a massive 3840 x 2160 Ultra HD resolution, all packed in to a 27" sized screen. As we touched on in our introduction section, the higher resolution is not about providing more screen real-estate here and we need to move away from thinking about LCD resolution in that manner. In fact it is arguable that the wide range of 2560 x 1440 resolution panels in the 27" sector are about as high a resolution as you want to go, without making fonts and icons too small natively. That provides a pretty comfortable option to work with day to day.

Here, with the resolution being so much higher it is about providing a sharper and crisper image, while still operating with a similar desktop area and similar font size to the 1440p models. It is providing a higher pixel density (Pixels Per Inch, PPI) to improve the degree of definition to the image. You need to us operating system scaling to handle this properly. If you try and run the screen without any scaling at 3840 x 2160 the 0.156mm pixel pitch makes everything far too small and tiny. In our view you need a screen of about 39 - 40" in size (like the Philips BDM4065UC) to use an Ultra HD or 4K resolution effectively without OS scaling. On this ViewSonic 27" model, if you increase the scaling to 150%, you actually end up with the same workspace area as 2560 x 1440, but at a much higher PPI pixel density - and therefore a sharper image. Have a read of Eizo's very useful article for some more information on the whole matter. For those wanting a high pixel density for CAD, design, photo work etc, this is a really good option. The image was very sharp and crisp and text was very clear.

Keep in mind that not all Operating Systems and applications handle scaling the same. More recent versions of Windows (8.1 and 10) tend to handle it all better, and recent versions of Mac OS are pretty solid as well. Some applications and games don't handle scaling correctly and so you can end up with some things with very minute text and fonts and some things which don't scale completely in every place. Keep this in mind if you're selecting any super high resolution display as it could be an important factor. You need to ensure you have the necessary operating system and applications to handle scaling effectively for your needs.

You do need to keep in mind the need for a compatible graphics card with a suitable output which can handle this resolution, and preferably at 60Hz refresh rate. DisplayPort and HDMI 2.0 are the only options to run the screen at its native 3840 x 2160 res at 60Hz, so are certainly recommended.  When running at native resolution this model is recognised as a single display which makes life easier than some of the early MultiStream (MST) models. It's also good to see support for 60Hz refresh rate as some 4k models only offer 30Hz support which is very limiting, even in day to day uses (certainly for gaming!).

The light AG coating of the panel is welcome, and much better than the grainy and 'dirty' appearance of older IPS AG coatings. The wide viewing angles provided by this panel technology on both horizontal and vertical planes, helps minimize on-screen colour shift when viewed from different angles. The default setup of the screen was strong thanks to the factory calibration, offering an accurate gamma curve and white point along with a decent contrast ratio and fairly low dE. The brightness range of the screen was also very good, with the ability to offer a luminance between 411 and 93 cd/m2. This should mean the screen is perfectly useable in a wide variety of ambient light conditions, including darkened rooms. We would have perhaps liked a little more control at the lower end, and a lower maximum luminance as >400 is unnecessary. A setting of ~8 in the OSD brightness control should return you a luminance close to 120 cd/m2 out of the box. On another positive note, the brightness regulation is controlled without the need for the use of the now infamous Pulse-Width Modulation (PWM), and so those who suffer from eye fatigue or headaches associated with flickering backlights need not worry. There was no audible noise or buzzing from the screen, even when specifically looking for it using test images with a large amount of text at once. The screen also remains cool even during prolonged use.

The screen offers 4x USB 3.0 ports (with charging capabilities also) which is very handy. There aren't any other extras like card readers or ambient light sensors offered though. The stand offers a wide range of adjustments which is great news, allowing you to obtain comfortable viewing positions easily.

Above: photo of text at 3840 x 2160 (top) and 2560 x 1440 (bottom)

The screen is designed to run at its native resolution of 3840 x 2160 and at a 60Hz recommended refresh rate. However, if you want you are able to run the screen outside of this resolution. We tested the screen at a lower 2560 x 1440 resolution to see how the screen handles the interpolation of the resolution, while maintaining the same aspect ratio of 16:9. At native resolution the text was very sharp and clear although you need scaling to ensure the image is useable without being tiny. When running at a 1440p resolution the text is still reasonably clear, with low levels of blurring. You do lose a lot of sharpness and image clarity though if you run at a lower resolution and let the screen scale it for you. You're better off running the screen at full resolution and letting your operating system and applications scale it back down to a comfortable viewing size.


Responsiveness and Gaming

Quoted G2G Response Time

5ms G2G

Quoted ISO Response Time


Panel Manufacturer and Technology

LG.Display AH-IPS

Panel Part


Overdrive Used


Overdrive Control Available to User

Response Time

Overdrive Settings

Standard, Advanced, Ultra Fast

The VP2780-4K is rated by ViewSonic as having a 5ms G2G response time, which indicates the panel uses overdrive / response time compensation (RTC) technology to boost pixel transitions across grey to grey changes. There is a user control over the overdrive impulse within the OSD menu using the 'Response Time' option also. The part being used is the LG.Display LM270WR2 AH-IPS panel. Have a read about response time in our specs section if you need additional information about response times and their measurement.

We will first test the screen using our thorough response time testing method. This uses an oscilloscope and photosensor to measure the pixel response times across a series of different transitions, in the full range from 0 (black) to 255 (white). This will give us a realistic view of how the monitor performs in real life, as opposed to being reliant only on a manufacturers spec. We can work out the response times for changing between many different shades, calculate the maximum, minimum and average grey to grey (G2G) response times, and provide an evaluation of any overshoot present on the monitor.

We use an ETC M526 oscilloscope for these measurements along with a custom photosensor device. Have a read of our response time measurement article for a full explanation of the testing methodology and reported data.

The VP2780-4K comes with a user control for the overdrive impulse available within the OSD menu in the 'manual image adjust' section as shown above. There are 3 options available here under the 'Response Time' setting. First of all we carried out a smaller sample set of measurements in all 3 of the settings. These, along with various motion tests allowed us to quickly identify which was the optimum overdrive setting for this screen.

With response time set to 'standard', the overall responsiveness was pretty slow. An average 13.4ms G2G was measured, with some rise times being particularly slow, up to 23.8ms here in the transitions measured. Since overdrive was turned down very low, maybe even off completely, there was no overshoot detected at all. However, moving images showed obvious blurring which we hope the other response time settings will help reduce.

The 'advanced' mode provided some obvious improvements. Response times had now sped up to 9.3ms G2G average, with the very slow transitions from before being boosted nicely. There was very little in the way of overshoot, although a few transitions started to show low levels in our measurements. Nothing you could really notice in practice though. This mode is definitely preferable compared with the 'standard' setting.

Switching up to the maximum 'Ultra Fast' mode improved response times again, now down to 7.8ms G2G average. However, it was at the cost of high and very noticeable levels of overshoot. This mode should be avoided really. Stick with 'advanced' mode.


If we take some test photos using the PixPerAn tool you can make some further visual comparisons between the overdrive settings. With response time set in the 'standard' mode there is a noticeable blurring to the moving image as response times are slow. When you move the setting up to 'advanced' the blurring is reduced nicely, and the moving image becomes clearer and sharper. No overshoot is apparent at this setting still. If you move to the 'ultra fast' mode there is a significant and very noticeable level of overshoot introduced, in the form of dark and pale trails. The advanced mode is certainly the optimum on this screen.


More Detailed Measurements

Response Time = Advanced

The average G2G response time was measured at 9.4ms which was fairly good for an IPS-type panel. Transitions to white (x > 255) and to black (x > 0) were the fastest, with some reaching down to as low as 7.3ms. None reached as low as the specified 5ms figure. Maybe that's achievable on some transitions with Response Time pushed up to Ultra Fast, but we know that it only introduces massive amounts of overshoot anyway. Intermediate changes between grey shades were slower, reaching up to 12.5ms in the worst case. To give you an idea, a fast 60Hz IPS-type panel can reach down to around 8.6ms G2G average without introducing lots of overshoot, so the VP2780-4K fell slightly behind here, but not by a massive amount really. It's not aimed at gamers so actually it's a pretty decent performance.

There was very little overshoot at this Response Time setting, with only a couple of transitions showing anything noticeable. Overall we were pleased with this setup as we wouldn't have wanted to sacrifice more overshoot really for the sake of a few tenths of a millisecond speed improvement.

Display Comparisons

The above comparison table and graph shows you the lowest, average and highest G2G response time measurement for each screen we have tested with our oscilloscope system. There is also a colour coded mark next to each screen in the table to indicate the RTC overshoot error, as the response time figure alone doesn't tell the whole story.

The measured response times of the VP2780-4K were reasonable for an IPS-type panel, measured at 9.4ms G2G average with very little overshoot. The fastest 60Hz IPS panels can reach down to around 8.6ms G2G without overshoot so that should give you an idea of where the ViewSonic lies. The previous ViewSonic VP2772 model (wide gamut, 1440p resolution) was a little bit faster at 8.8ms G2G response time but had moderate levels of overshoot, higher than on the new VP2780-4K. The new 144Hz capable IPS-type panels in the Asus MG279Q and Acer XB270HU are faster, reaching down to 5.5 - 6.5ms with little to no overshoot. Modern TN Film panels are faster than the VP2780-4K as well as you might expect, reaching down to 2.9 - 3.4ms G2G average on models like the Asus ROG Swift PG278Q and BenQ XL2730Z respectively, but only at the cost of moderate levels of overshoot being introduced.


The screen was also tested using the chase test in PixPerAn for the following display comparisons. As a reminder, a series of pictures are taken on the highest shutter speed and compared, with the best case example shown on the left, and worst case example on the right. This should only be used as a rough guide to comparative responsiveness but is handy for a comparison between different screens and technologies as well as a means to compare those screens we tested before the introduction of our oscilloscope method.

27" 5ms G2G LG.Display AH-IPS (Response Time = Advanced)

In practice the VP2780-4K showed low levels of blurring in these tests, with the moving object looking sharp and clear. There was no overshoot detected in these specific tests at this setting, but we know there are some low levels of overshoot on some transitions form our oscilloscope tests.

27" 5ms G2G LG.Display AH-IPS (Response Time = Advanced)

27" 6ms G2G LG.Display AH-IPS (Response Time = Advanced)

27" 12ms G2G Samsung PLS (Response Time = Advanced)

27" 8ms G2G LG.Display AH-IPS (Response Time = Normal)

It is also interesting to compare the VP2780-4K with the previous ViewSonic 27" VP models. The old VP2772 (wide gamut, 1440p resolution) showed pretty similar levels of blurring in practice, but did have a more obvious overshoot issue than the new screen. Before that, the VP2770-LED (standard gamut, 1440p) was perhaps slightly slower but was free from overshoot problems at least. The popular Dell U2715H (1440p) was very similar to the VP2780-4K overall really, perhaps ever so slightly slower.

27" 5ms G2G LG.Display AH-IPS (Response Time = Advanced)

27" 4ms G2G AU Optronics AHVA (IPS-type) @ 144Hz (OD = Normal)

27" 1ms G2G AU Optronics TN Film @ 144Hz (OD = Normal)

27" 1ms G2G AU Optronics TN Film @ 144Hz (AMA = High)

23.5" 4ms G2G Sharp MVA + 120Hz

We've also included a comparison above against some other very fast 120Hz+ compatible screens we have tested. The screens shown here are all aimed primarily at gamers and have various features and extras which make them more suitable overall for gaming. Firstly there is a comparison against the excellent Acer XB270HU with very fast response times (5.5ms G2G, no overshoot), 144Hz refresh rate and also NVIDIA G-sync and Ultra Low Motion Blur (ULMB) support. It's currently our bench-mark for IPS panel gaming - well, actually our current favourite gaming screen of any type!

Then there's the very popular Asus ROG Swift PG278Q with its 144Hz refresh rate and fast response time TN Film panel. This showed very fast pixel response times (2.9ms G2G), with moderate levels of overshoot, but smooth movement thanks to its increased refresh rate. You are able to reduce the motion blur even more through the use of the ULMB strobed backlight as well if you need to and again this model also supports NVIDIA's G-sync technology.

Then there is a comparison against the BenQ XL2730Z with another very fast TN Film panel and 144Hz refresh rate. This showed very low levels of motion blur (3.4ms G2G), but some dark overshoot was introduced as a side-effect as you can see. This screen also includes a native Blur Reduction mode to help eliminate further perceived motion blur and works well, along with AMD FreeSync support.

Lastly there is the MVA based Eizo Foris FG2421 screen with a fast response time (especially for the panel technology being used) and 120Hz refresh rate support. There is also an additional 'Turbo 240' motion blur reduction mode which really helps reduce the perceived motion blur in practice.

On another note the Ultra HD resolution is also very impressive for games, providing a very sharp image and a lot of detail. Images look sharp and crisp even up close. One big consideration you need to make is that the 3840 x 2160 @ 60Hz resolution is likely to be a major drag on even high end graphics cards and PC systems when it comes to gaming. You really need to think about the type of game you want to play, the settings you want to use, and whether your system can handle outputting such a high resolution effectively. Your graphics card will also need to support DisplayPort 1.2 or HDMI 2.0. Other interfaces including the HDMI 1.4 inputs are limited to 30Hz at 3840 x 2160. Don't forget that many gaming titles don't support this 4k resolution either, so that could be another issue. Some games don't handle scaling very well and so when it comes to the user interface a lack of scaling results in tiny text or hard to read maps etc. Be wary of that as well as the game needs to handle scaling properly on a screen this size.

One option of course is to run the game at a lower resolution and let the screen scale it. That's probably the most sensible option in most cases and we know that the interpolation of lower resolutions like 2560 x 1440 and 1920 x 1080 is pretty good on this model. It does kind of defeat the point of having a 4k resolution in the first place though. If you have games which can natively support this resolution properly, they would look fantastic given the very high resolution and high pixel density. External games consoles running at 1080p will still look ok, and the image is interpolated quite well.

Additional Gaming Features

  • Aspect Ratio Control - The VP2780-4K has three options in the menu for aspect ratio control. There are options for 1:1 pixel mapping, full screen and 4:3 only. There is no "aspect" option to maintain the source aspect at whatever it is, but fill the screen as much as possible. This isn't a major problem on this screen as if you're using a PC and want to run at a non-native resolution (for gaming etc) you can let the graphics card handle the scaling instead. Since the screen is a native 16:9 aspect ratio as well, if you are using an external device (games console, Blu-ray player) it should be ok since those generally run at 16:9 aspect themselves. External inputs not from a PC of 16:10, 5:4 aspect ratios will be an issue though unless you run them at 1:1 pixel mapping, which will be a very small window given the resolution of the panel.

  • Preset Modes - There are a specific game preset modes available on this screen in the 'Viewmode' option of the 'manual image adjust' section of the OSD. This seems to have a slightly different gamma curve than the default ~2.2, and it also results in a locked brightness/contrast section. It might be easier to just change your standard mode to suit your gaming.


We have written an in depth article about input lag and the various measurement techniques which are used to evaluate this aspect of a display. It's important to first of all understand the different methods available and also what this lag means to you as an end-user.

Input Lag vs. Display Lag vs. Signal Processing

To avoid confusion with different terminology we will refer to this section of our reviews as just "lag" from now on, as there are a few different aspects to consider, and different interpretations of the term "input lag". We will consider the following points here as much as possible. The overall "display lag" is the first, that being the delay between the image being shown on the TFT display and that being shown on a CRT. This is what many people will know as input lag and originally was the measure made to explain why the image is a little behind when using a CRT. The older stopwatch based methods were the common way to measure this in the past, but through advanced studies have been shown to be quite inaccurate. As a result, more advanced tools like SMTT provide a method to measure that delay between a TFT and CRT while removing the inaccuracies of older stopwatch methods.

In reality that lag / delay is caused by a combination of two things - the signal processing delay caused by the TFT electronics / scaler, and the response time of the pixels themselves. Most "input lag" measurements over the years have always been based on the overall display lag (signal processing + response time) and indeed the SMTT tool is based on this visual difference between a CRT and TFT and so measures the overall display lag. In practice the signal processing is the element which gives the feel of lag to the user, and the response time of course can impact blurring, and overall image quality in moving scenes. As people become more aware of lag as a possible issue, we are of course keen to try and understand the split between the two as much as possible to give a complete picture.

The signal processing element within that is quite hard to identify without extremely high end equipment and very complicated methods. In fact the studies by Thomas Thiemann which really kicked this whole thing off were based on equipment worth >100,1000 Euro, requiring extremely high bandwidths and very complicated methods to trigger the correct behaviour and accurately measure the signal processing on its own. Other techniques which are being used since are not conducted by Thomas (he is a freelance writer) or based on this equipment or technique, and may also be subject to other errors or inaccuracies based on our conversations with him since. It's very hard as a result to produce a technique which will measure just the signal processing on its own unfortunately. Many measurement techniques are also not explained and so it is important to try and get a picture from various sources if possible to make an informed judgement about a display overall.

For our tests we will continue to use the SMTT tool to measure the overall "display lag". From there we can use our oscilloscope system to measure the response time across a wide range of grey to grey (G2G) transitions as recorded in our response time tests. Since SMTT will not include the full response time within its measurements, after speaking with Thomas further about the situation we will subtract half of the average G2G response time from the total display lag. This should allow us to give a good estimation of how much of the overall lag is attributable to the signal processing element on its own.


Lag Classification

To help in this section we will also introduce a broader classification system for these results to help categorise each screen as one of the following levels:

  • Class 1) Less than 16ms / 1 frame lag at 60Hz - should be fine for gamers, even at high levels

  • Class 2) A lag of 16 - 32ms / One to two frames of lag at 60Hz - moderate lag but should be fine for many gamers. Caution advised for serious gaming and FPS

  • Class 3) A lag of more than 32ms / more than 2 frames of lag at 60Hz - Some noticeable lag in daily usage, not suitable for high end gaming

For the full reviews of the models compared here and the dates they were written (and when screens were approximately released to the market), please see our full reviews index.

(Measurements in ms)


Total Display Lag (SMTT 2)


Pixel Response Time Element


Estimated Signal Processing Lag


Lag Classification



 Class 1

We have provided a comparison above against other models we have tested to give an indication between screens. The screens tested are split into two measurements which are based on our overall display lag tests (using SMTT) and half the average G2G response time, as measured by the oscilloscope. The response time is split from the overall display lag and shown on the graph as the green bar. From there, the signal processing (red bar) can be provided as a good estimation.

The VP2780-4K showed a total display lag of 15.0ms. 4.70ms of this can be accounted for by pixel response times roughly, leaving us with approximately 10.3ms of signal processing lag. This is less than 1 frame at 60Hz refresh rate and is a good result and low level of lag. It should be fine for most gamers, although some people wanting to play FPS or competitive games might need something even lower.

Movies and Video

The following summarises the screens performance in video applications:

  • 27" screen size makes it a reasonable option for an all-in-one multimedia screen, much smaller than LCD TV's and many larger format desktop monitors which are now emerging.

  • 16:9 aspect ratio is well suited to videos and movies, leaving you with smaller/no borders on DVD's and wide screen content at the top and bottom than on a 16:10 aspect display.

  • 3840 x 2160 resolution can support full 1080 HD resolution content and also Ultra HD "4k" content natively.

  • Digital interfaces support HDCP for any encrypted and protected content

  • Good range of interface options available here with DisplayPort, Mini DP, HDMI 1.4 (x2), MHL 2.0 (x2) and HDMI 2.0 available.

  • Cable provided in the box for DisplayPort, MHL and HDMI.

  • Light AG coating provides clear images with no major graininess, and without the unwanted reflections of a glossy solution.

  • Wide brightness range adjustment possible from the display, including high maximum luminance of ~411 cd/m2 and a good minimum luminance of 93 cd/m2. This should afford you very good control for different lighting conditions. Contrast ratio remains stable across most of that adjustment range as well and is excellent for an IPS-type panel at >1000:1. Brightness regulation is controlled without the need for PWM and so is flicker free at all settings which is pleasing.

  • Black depth and contrast ratio are very good for an IPS-type panel at 1002:1 after calibration. Detail in darker scenes should not be lost as a result.

  • Good pixel responsiveness which can handle fast moving scenes in movies without issue. No noticeable overshoot issues as long as you stick to the 'advanced' response time setting.

  • Wide viewing angles from IPS panel technology meaning several people could view the screen at once comfortable and from a whole host of different angles. Pale glow from an angle on black content may be problematic to some users and is common for IPS panel technology.

  • No real backlight leakage on our sample but results may vary.

  • Very good range of ergonomic adjustments available from the stand, with tilt, height, swivel and rotate offered. Should be easy enough to get a comfortable setup for movie viewing from different viewing positions.

  • No integrated speakers provided on this model, but there is a headphone connection for audio pass through over HDMI.

  • Hardware aspect ratio control provided with options for full, 1:1 pixel mapping and 4:3. Missing an "auto aspect" which may be problematic for some external devices depending on their source aspect ratio.

  • Picture By Picture (PbP) or Picture In Picture (PiP) are available on this model if you want to use them.



The VP2780-4K offered a very good all-round screen with a robust and sturdy design and feature set. The versatile stand, wide range of connectivity options and useful extras like USB 3.0 ports and PiP/PbP were pleasing, and showed that ViewSonic continue to offer high end features from their VP series. The design of the screen is fairly industrial and perhaps lacks the wow factor of some alternative designs in the market. Maybe the stand needs a bit of a refresh in the future? However, it is solid and reliable and will no doubt suit a lot of people's taste all the same.

This is the first of their VP range to offer Ultra HD 3840 x 2160 resolution, and it does this well - offering 60Hz refresh rate support over both DisplayPort and HDMI 2.0. As ever with super high resolutions like this you need to keep in mind the support for effective scaling from your operating system and applications. You also need to consider the demands on your graphics card when it comes to multimedia uses at such a high resolution. The high pixel density on a 27" screen size provided a sharp and clear image which is the main aim of course.

In other performance areas the factory calibration provided a decent default setup with reliable gamma, white point and a strong contrast ratio. You don't have the option of wide gamut support on this model like the previous VP2772, so keep that in mind if you wanted to work with wide gamut content. The flicker free backlight and light AG coating were welcome as ever and although the response time was slightly slower than other 60Hz IPS panels it was still pretty decent, and at least free from noticeable overshoot. The display lag was also pretty low and so the screen could be a reasonable option for Ultra HD gaming on an IPS panel at the moment. There were only really a couple of minor performance negatives we felt. We would have gladly sacrificed a bit off the top end of the very high brightness adjustment range for the sake of a bit more control at the lower end in an ideal World. Also there wasn't an aspect ratio option to maintain the source aspect but fill more of the screen. You have 1:1 at least, but we would have liked this additional option. Overall though we are picking a bit and the screen impressed us with very good all-round performance and a wide selection of extras.

If you appreciate the review and enjoy reading and like our work, we would welcome a donation to the site to help us continue to make quality and detailed reviews for you.



Good connectivity options and stand ergonomics provided

Industrial design maybe not to everyone's taste. Stand is quite deep

High pixel density provides very sharp image

Minimum brightness range could have been slightly better

Good factory calibration and default setup

Missing an aspect ratio control option to maintain source aspect, but fill more of the screen.



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