Most HDTVs , tablets , smartphones , laptop , and monitors conspicuously list their video display specification as a sale and marketing tool . Unfortunately , many of these specs are misleading , and are misunderstood by both consumer and professional . This makes it hard to figure out which display are really better . Below are many of the glasses you ’ll see together with brief explanations that will aid you interpret what they in reality mean .
For in - depth explanations see our article serial onMobile DisplaysandHDTV and multimedia system presentation .
Just because a manufacturer lists “ proficient specifications ” does n’t have in mind those telephone number are true — very often it ’s merchandising dressed up as science . Dr. Raymond Soneira of DisplayMate Technologiesbreaks down some ordinarily deceptive specs so you do n’t get fooled by the lies .
Screen Size : This specification voice straightforward — it ’s just the diagonal duration of the screen . True , but that does n’t actually tell you how big the cover really is . What really count visually is the area of the screen ( width times height ) and that changes importantly quicker than the diagonal size of it indicates , so you ’ll either over or under estimate the true visual sieve size establish on just its sloping size of it . To get an approximation of the screen surface area , square the slanting sizing ( multiply it by itself on a calculator ) and employ that for comparison . For example , a 7 column inch Tablet really has less than half the area ( 49 ) of a 10 in Tablet ( 100 ) . The area also depend on the physical body of the screen , which is another spec call aspect ratio ( below ) . Lower scene proportion have large projection screen areas for the same diagonal size . For example , a 10 - inch , 4:3 Aspect proportion screen is 12 - pct larger in area than a 10 - inch , 16:9 CRT screen . If you ’re not handy with this mathematics , you ’ll often see the factual CRT screen width and stature listed in the specs . Just multiply them on your calculating machine to get the area .
16:9 and 4:3 Aspect Ratios : The aspect proportion is the blind width divided by its tallness and it ’s the specification used to point the bod of the screen . It can be trace as a proportion — like 16 by 9 — or numerically by split the two numbers—1.78 . For all consumer displays you could also get the Aspect proportion by dividing the screen ’s listed horizontal and vertical pixel resolution – dividing 1920 by 1080 is also 1.78 . 16:9 is the stock aspect proportion for high-definition television capacity , so it tally perfectly on 16:9 screen . While that ’s often called “ widescreen ” most widescreen moving picture have aspect ratios much heavy than 16:9 , so you ’ll see black “ Letterbox ” bars on the top and bottom of the cover , which reduce the effective viewable screen size and resolution . Another usual view proportion is 4:3 or 1.33 , which is also the same aspect proportion as cognitive content from 8.5 x 11 - column inch documents . This facial expression proportion is better for reading in either Landscape or Portrait modes , but not as good for viewing widescreen subject . The iPad has a 4:3 aspect proportion and the iPhone has 3:2 or 1.5 . Other vernacular aspect ratios are 5:3 or 1.67 and 16:10 or 1.6 .
PPI Pixels Per Inch : As a result of Apple ’s retina displays , pixels per column inch is a very spicy spec – it ’s one of the most intimately followed display Specs , but it ’s also one of the most misunderstood . True , the higher the PPI the sharper the prototype on the screen , but what really matters is the sharpness perceived by your eye and that depend on the viewing distance from the screen ( and also how adept your visual modality is compared to 20/20 Vision ) . So PPI can not be used by itself , but must be used together with the viewing distance in social club to pull back any conclusions about optical bite , and whether or not it qualifies as a retina exhibit . While the iPhone 4 has an impressive 326 PPI , it is typically hold comparatively penny-pinching and view from around 12 inches . Larger show like tablet and laptops are typically consider from 16 in or more and need only 215 PPI to appear perfectly discriminating with 20/20 Vision ( what Apple calls aretina display ) . In fact , exist 1920×1080 HDTVs , which are viewed from much larger distances , are already what Apple calls retina displays as explain in thisdisplay intelligence article .
Color Gamut : The colour gamut is the kitchen range of colors that a display can produce . A widely held and exploited misconception is that the bigger the color gamut the better – but it is n’t … If you require to see accurate colors in photos , videos , and all standard consumer content the display needs to pit the Standard color gamut that was used to bring out the capacity , which is call sRGB / Rec.709 . A display with a larger colour gamut can not show colour that are not in the original content – it just exaggerates and distorts the colour . A smaller colour gamut produces subdued people of color , and too with child a colour gamut produce over concentrated and even gaudy color . That ’s why a smaller coloring material gamut is visually better than too large a color gamut . Most LCDs have a color gamut smaller than the Standard and most OLEDs have a colour gamut large than the standard , as illustrated in thisfigure . We objectively mensurate the color gamut in all of ourmobile shoot - outsandHDTV shoot - outs .
NTSC Color Gamut : You ’ll see the NTSC colouration gamut spec listed for some display and reviews . It ’s an indication that the manufacturer or reviewer is path out of touch . The NTSC Color gamut was defined about 60 years ago in 1953 and has been obsolete for over 30 year . It was never really a true color gamut standard because consumer tv never bring forth the NTSC Gamut even right smart back then . specify the ancient NTSC rather of the current sRGB / Rec.709 Color Gamut Spec is laughable …
16 Million Colors : You ’ll see this Spec for most high-definition television , Tablets , Smartphones , Laptops and Monitors . 16 Million Colors is effectively the criterion for most consumer depicted object ( including digital tv camera ) . But it does n’t mean what most masses imagine it does – a large number of colour does NOT signify a larger color gamut – it is merely the total number of possible compounding of the flushed , green and blue primary color vividness . The primary quill each have 256 possible intensity level levels – that produces 256x256x256 = 16.7 Million possible chroma combination , which are not really color in the nonrational sense . There is also mickle of duplication – for example , utter red counts as 256 Colors . Not all display can grow 16 million colors – you ’ll sometimes see 262,144 gloss , and some that arrogate 16 million colors ca n’t straight off produce them – more on that under 18 - number and 24 - bit people of colour , below .
jillion and Trillions of Colors : Some display spec list billions and even trillions of coloration , which as explained above does not bespeak a tumid colouring material gamut , but rather is just the entire bit of saturation combinations produced by the basal colour . What happens is those video display process the double internally using 1,024 or more intensity levels . When you multiply this out as above you get billions up to trillions of intensity combinations , which sounds very telling . But this Spec is misleading and visually useless for two reasons : most consumer content only has 256 chroma level ( and that ’s all there is ) and very few showing can accurately bring on even the stock 256 intensity levels on - screen , which is the only lieu where it weigh ( most display have abnormality that result in few than 256 distinct intensity level on - screen ) . If you see a spec listing billion or trillions of colors consider it nonmeaningful merchandising puffery …
18 - bit and 24 - bit Color and Dithering : As observe in 16 million colouring above , the Spec for the telephone number of colors is actually just the total number of possible intensity combinations for the red , green and dreary primary . For 16 million colors , each primary color needs 256 intensity levels , which is 8 - bit in binary . Since there are 3 master colour and each has 8 - bits , they impart up to 24 - routine . That ’s called 24 - flake coloring and you ’ll sometimes see this Spec name instead of 16 million colour . Some crushed execution displays can only make 64 intensity level , which is 6 - bits per primary and summate up to 18 - bits . That ’s called 18 - snatch people of colour and it bring about only 262,144 color . But the real job is actually the little number of 64 intensity horizontal surface , which often present visually detectable distinct steps into effigy that have tranquil variations in strength – from faces to the sky – it ’s called put on contouring . This impression is often block out by using two methods of dithering : spacial dithering , which utilize combination of pixels to raise intermediate chroma story , but that reduce image edge ; and worldly dithering , which chop-chop switch the intensities to produce intermediate chroma levels , but may bring on noticeable flicker in some content . A word of caveat : some 18 - bit presentation with 262,144 gloss use dithering method to claim full 24 - bite and 16 million colors . It ’s possible to detect the dithering on images with close optical inspection .
170 + Degree Viewing Angles : Many HDTV , tablets , smartphones , laptops and monitors list a viewing angle spec , which is the full angle ( compare to 180 degrees ) within which the display can purportedly be watched with satisfactory picture caliber . 170 degrees is 85 degrees out of a possible 90 level . The specification seems to entail that unless you are watching from a absurd 5 degrees from the edge of the CRT screen you will see a absolutely ok simulacrum on the screen . This spec is meaninglessness and very misleading because it is defined for the slant where the dividing line proportion ( below ) come to an abysmal 10 . That is mostly less than 1 - percentage of the contrast proportion see when consider the covert expression on – so the pic tone will also be abyssal at that viewing angle . watch from other than the nerve - on center sweet spot in the main decreases image and word-painting timbre for efficaciously all display . For example , in gamey - endIPS LCDsthe brightness and contrast ratio both fall by roughly 50 percent at 30 degrees . Forother LCDsthere are also obtrusive people of colour fracture at 15 degree as designate in thisarticle . ForOLED displayswe measured a 30 percent brightness decrement and noticeable color shifting at 30 degree . So , the stock consider slant specification is useless . We objectively mensurate viewing slant execution in all of ourmobile shoot - outsandHDTV shoot - out . The good elbow room to evaluate it yourself is to search at a fixed ( wintry ) jolly colorful epitome or photo and see how the image changes as you shift your viewing position .
Contrast proportion : Contrast proportion is the spec that tell you how serious the display is at reproducing relatively drear content , particularly at or near ignominious . It is measured in an utterly sales talk black Lab . It is very important if you watch movies with dark capacity under low ambient inflammation . It ’s not so important if you are watching in bright ambient lighting ( like for many HDTVs and most fluid devices ) or when watch average television appearance and sporting event ( because they have almost no dark content ) . Mobile displays should have at least a true contrast proportion of 500 and home theater HDTV at least 1,500 ( a good LCD ) . Videophiles will want at least 4,000 from Plasma HDTVs , and are wait uneasily for the much higher values in the new OLED high-definition television , as explained in thisdisplay news article .
dynamical and Mega Contrast Ratios : You ’ll often see display advertised with contrast proportion from 20,000 up into the millions . Unless it ’s an OLED showing ( which can easy do that ) it ’s a phony dynamical direct contrast ratio . The news dynamic may or may not seem . This dividing line ratio is count on by using the maximum peak luminousness from one image with the minimum brightness from a unlike image that has a darkened Backlight – so it does n’t apply to any actual individual image , which makes it very misleading , peculiarly when the news dynamic is left out . The honest dividing line ratio is what you actually see on any single icon . The best LCDs have true contrast ratios of around 2,000 and the honest Plasmas around 5,000 , so ignore values much larger than that as marketing puffery . OLEDs deliver true demarcation Rratios from 50,000 up to almost infinity .
Response Time : This is another over - hyped specification that is a prime instance of marketing wars crusade with misleading number . liquid crystal display sometimes bring forth visible Motion Blur because the Liquid Crystal ( the LC in LCD ) ca n’t respond fast enough from video frame to redact when images change quickly due to motion , resulting in a bleary image . Standard video content is update 60 times per second base , so a new frame is transmitted every 17 milli - seconds . In principle , the Response Time measures how quickly the display responds in milli - seconds . It ’s important to make that phone number a heap smaller than 17ms ( milli - seconds ) . A lot of advanced technology has go into improving the ironware answer time , but also a lot of advanced selling has gone into ameliorate the release response time glasses , with the values falling sharply from 8ms , to 4ms , to even 1ms . Using gamy pep pill screen shots in thisarticlewe demonstrated that the true documentary response times are actually considerably long than 30ms . So the response meter specification is mostly meaningless merchandising puffery …
lead television and display : This one really amazes me because there are n’t any LED TVs or consumer light-emitting diode displays – the only true LED showing are large commercial outdoor signs . What are being marketed as LED TVs and Displays are actually LCD TVs and Displays . The light-emitting diode are just the backlight for the LCD — nothing more — very deceptive ..
brightness level : In principle , the mellow the maximal smartness spec the good , but the great unwashed often set the CRT screen brightness too high-pitched , which causes eye strain and wastes power ( and repress electric battery running time ) . The optimal screen brightness varies with the current story of ambient lighting . Many displays have automatic brightness controls that should appropriately adjust the screen smartness , but we have discover them all to be functionally useless as explained in thisarticle . High screen luminosity is only useful when you need to look at the screen under eminent ambient ignition . But under these circumstances the reflectance of the screenland is really more significant than the blind Brightness because it wash out the image , and you generally see reflections of your face and the surface area behind you , which is perturb and causes eye strain from involuntarily concentre on them alternatively of the silver screen content , which is much tightlipped . We objectively quantify the brightness and screen reflectivity in all of ourmobile shoot - out .
line Rating for High Ambient Light : Contrast ratios ( above ) are measured in the dark and are only relevant for display viewed in low Ambient Lighting . As the ambient light increases the Screen reflectance becomes a dominating factor and the line ratio becomes more and more irrelevant . We have defined a new specification called contrast rating for mellow ambient light . It is based on brightness and reflectance lab measurements that accurately indicate how well a exhibit performs in high Ambient Lighting . Thisarticleincludes the contrast rating , lab measurements , and CRT screen shots for nine lozenge and smartphones for ambient lighting levels up to 40,000 lx .
Anti - Glare or Anti - Reflection Treatments : Many displays list within their specs that they have anti - glare or Anti - Reflection properties , but most of the time it ’s a fatuous affirmation . Our research lab tests show that there is a tremendous 3 to1 range in Reflectance between many popular Tablets and Smartphones . We objectively measure out the screen coefficient of reflection in all of our mobile shoot - out . Thisarticlehas the lab results plus screenland shots showing how the screens of various tablets and smartphones degrade under high ambient lighting levels up to 40,000 lux .
About DisplayMate Technologies
DisplayMate Technologiesspecializes in advanced mathematical show technology optimization and precision analytical scientific exhibit nosology and calibrations to turn in spectacular image and flick quality and accuracy – while increasing the effective ocular Contrast Ratio of the video display and produce a higher calibrated light than is realizable with traditional calibration methods . This also decreases display exponent requirement and increase the assault and battery run time in nomadic displays . This article is a calorie-free edition of our intensive scientific analysis of smartphone and mobile displays – before the benefits of our advanced mathematicalDisplayMate Display Optimization Technology , which can compensate or better many of the deficiencies – including high fine-tune brightness , power efficiency , in effect screen door contrast , picture quality and color and gray ordered series accuracy under both brilliant and dim ambient spark , and much more . Our forward-looking scientific optimizations can make low cost control panel reckon as good or better than more expensive higher performance displays . For more entropy on our technology see the Summary description of ourAdaptive Variable Metric Display Optimizer AVDO . If you are a presentation or mathematical product manufacturing business and want our expertise and technology to turn your display into a spectacular one to surpass your competitor thenContact DisplayMate Technologiesto learn more .
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