crt and lcd monitors free sample

CRT monitors have surged back to relevance on a wave of nostalgia, driven by the exploding popularity of retro gaming. Unfortunately, most of the reviews, specification sheets, and comparison data that once existed has vanished from the Internet, making it difficult to know what you should look for while scanning eBay and Craigslist ads.

If you’re looking for a newer display filled with the latest and greatest goodies, our guides to the best PC monitors, best 4K monitors, and best gaming monitors can help you find the perfect fit for your needs. But this particular guide will get you up to date on aging, but still hotly desired CRT monitors.

CRT monitors fell from fashion with the same breathtaking speed as portable CD players and vinyl records. Three out of four monitors sold in 2001 were a CRT. But in 2006, Sony drew curtains on the era when it ceased production of new CRT TVs and monitors.

Still, CRTs have their perks. Most have a better contrast ratio and higher refresh rates than modern LCD monitors, so content looks richer and deeper. There’s a sub-culture of first-person shooter fans who swear FPS games always look best on a high-end CRT monitor.

A CRT is also a window into an entire era of media. Films, movies, and games produced from the dawn of television to around 2004 were created with a CRT in mind. You can enjoy older media on a modern LCD or OLED, but it will never look as originally intended. A CRT computer monitor is the most versatile, practical choice for tapping into nostalgia.

One quick note: This guide is for CRT computer monitors, not professional video monitors. PVMs are high-end CRT televisions. They’re amazing for retro console gaming but aren’t designed for use with a computer.

Sony’s Trinitron dominates the conversation just as it does in the world of retro CRT televisions and PVMs. Trinitron computer monitors are excellent, easy to find, and come from Sony, a brand people still recognize today. Other outstanding brands include Mitsubishi, Hitachi, LaCie, NEC, Iiyama, and Eizo.

Dell, Gateway, HP, and Compaq monitors are less loved, but this can be an opportunity. Large PC manufacturers didn’t make monitors in-house but rebranded monitors from others, and some use the same CRT tubes found in Trinitrons and other brands. Deciphering what’s in a rebrand can be difficult, though, so you may need to take a leap of faith.

I don’t recommend fretting brands and models if this is your first CRT. Trying to find a specific monitor is frustrating and, depending on your dream monitor, can take years (or cost thousands of dollars). Still, keep brand in mind when negotiating price. A Gateway monitor with mystery specifications might look great, but it’s not worth top dollar.

CRTs were improved and refined over the years. The oldest CRT monitors commonly sold are pushing forty years of age. They have a low maximum resolution, a low refresh rate, and small physical display size.

Newer CRT monitors, such as those produced in the mid-90s and the 2000s, will look sharper, handle reflections better, and have less noticeable lines or gaps in the image they display. You’re also find better on-screen menus with extensive image quality options.

Luckily, CRT monitors often have a label indicating the year or even month of production. This is printed on the rear of the display or might be found on a sticker in this same location. Newer is better, and a CRT built this millennia are best.

Most CRT computer monitors have a display size between 13 and 21 inches. If you follow my advice and stick with newer monitors, though, you’ll be comparing monitors between 15 and 21 inches.

I don’t recommend going below 17 inches unless you’re trying to replicate the experience of a late-80s or early-90s computer or have very limited space. Smaller CRT monitors feel tiny by modern standards. They also tend to support lower resolutions that are only ideal for enjoying older content.

There’s such a thing as too large, too, so be cautious about massive CRTs. A 21-inch CRT monitor can weigh 50 or 60 pounds. You’re unlikely to run into a CRT computer monitor larger than 21 inches, and if you do, it can weigh nearly 100 pounds. The Sony GDM-FW900, a truly epic 24-inch 16:9 CRT, is the most well-known of these rare beasts.

19 inches is the sweet spot. This size of CRT monitor remains manageable. It’s about as tall as a 24-inch LCD (though narrower, of course) and isn’t too hard to find. With that said, 17-inch monitors are more common and less expensive, so don’t hesitate to leap on a 17-incher if you find one.

Resolution works differently on a CRT computer monitor than on a modern LCD. CRT monitors are an analog technology and don’t have a native resolution. CRT monitors were sometimes marketed with a “recommended” resolution that served as a guideline, but CRTs computer monitors support a range of input resolutions and refresh rates.

Take the Hitachi SuperScan 751 as an example. This 19-inch CRT computer monitor lists a maximum resolution of 1600 x 1200 at 85Hz but supports 1024 x 768 at 130Hz and 640 x 480 at 160Hz.

In general, the best resolution is the highest you can find. A monitor with a high maximum resolution will also support lower resolutions, and often a higher refresh rate. A resolution of 2048 x 1536 is the highest you’re likely to see. 1600 x 1200 is more common.

The importance of resolution depends on your use. I use my CRT monitor to run Windows 95/98 in a virtual machine, play late-90s PC games, and emulate console games. All of these were designed with lower resolutions in mind, so the content I’m viewing is usually at a resolution of 1024 x 768 or lower.

If you want to use a CRT monitor to play Doom: Eternal at insane refresh rates with near-perfect response times, however, you’ll prefer the highest resolution you can find. Resolution is not the final word on CRT monitor sharpness but in general a higher resolution will appear sharper.

Dot pitch is the distance between dots in a shadow mask or the distance between wires in an aperture grill. More on that in a moment. Remember that a CRT shoots electrons at the front of the display. The shadow mask or aperture grill filters the electrons so they hit phosphors at the front of the display and create a usable color image. The gaps in the shadow mask or aperture grill influences how sharp the image appears.

Dot pitch is measured in millimeters. I recommend monitors with a horizontal dot pitch around .28 millimeters or lower. A dot pitch between .24 millimeters and .21 millimeters is excellent. Lower is better, but you likely won’t find a monitor with a dot pitch below .21 millimeters in your search.

Make dot pitch a priority if you care about sharpness at resolutions beyond 1600 x 1200. A monitor with a lackluster dot pitch might support a high resolution but appear blurrier at a high resolution than a low resolution. This occurs when a CRT monitor’s dot pitch isn’t up to the task.

Dot pitch is less important if you only care to use a CRT at lower resolutions. Late-model CRT monitors will be enjoyable at 800 x 600 or 1024 x 768 no matter the dot pitch listed on their spec sheet.

A shadow mask or aperture grill is a filter a CRT computer monitor uses to make sure electrons end up where they should be. A shadow mask does the job with a metal mask of evenly spaced holes. An aperture grill uses an array of wires instead. Sony was the first to introduce aperture grill technology under the Trinitron brand name, but Sony wasn’t the only company that sold CRT monitors with an aperture grill.

In general, a monitor with an aperture grill will be superior to one with a shadow mask. The aperture grill blocks less light than a shadow mask, which translates to a brighter and more colorful picture. The aperture grill is also better suited for a flat CRT display, though flat shadow mask CRTs were produced.

That’s not to say shadow masks were trash. Hitachi and NEC put a ton of effort into shadow mask technology to rival Sony’s Trinitron and had success. A late-model Hitachi ErgoFlat or NEC ChromaClear is a great monitor. If you’re comparing two random, mid-range monitors, though, the aperture grill will probably be brighter and more attractive.

As mentioned, CRT monitors support a range of resolutions and refresh rates. The higher the resolution, the lower the refresh rate. Most late-model CRT monitors had a refresh rate of at least 75Hz at maximum resolution. Lower resolutions come with higher supported refresh rates with the best models topping out at 200Hz.

Refresh rate and resolution are linked. CRT monitors with the best refresh rates also support the highest resolutions. If you want the best refresh rate, then, you’ll need to keep an eye out for a top-tier CRT monitor, and you should expect to use it at a resolution lower than the maximum it supports.

Obsessing over a CRT’s refresh rate is often not worth the trouble. CRT monitors feel smooth not just because of refresh but also thanks to fundamental differences in how an image is produced. Nearly all late-model CRT monitors support a refresh rate of at least 75Hz at their maximum supported resolution and look exceptionally smooth.

Most CRT televisions and monitors have curved (also known as convex) glass. This was necessary to fix some problems of CRT technology. CRT makers found ways to overcome these issues by the mid-1990s and flat CRT displays hit the market. Shoppers loved them and flat-screen models dominated the final years of CRT production.

The big difference is the most obvious: Curved CRT monitors are curved, and flat CRT monitors aren’t. Your choice should come down to the “feel” you’re going for. A curved CRT will feel more accurate to a mid-90s PC or earlier, while flat screens were more common after the turn of the millennium. Those looking to use a CRT with modern software and games will prefer a flat screen as well.

The vast majority of CRT computer monitors you’ll encounter have a VGA video input. This is likely the only input on the monitor. It’s an analog technology that most modern computers do not support, so you’ll need an active DisplayPort or HDMI to VGA adapter. I use a StarTech adapter from Amazon.

Be careful about the adapter you purchase. Many, including the one I purchased, have a maximum resolution and refresh rate below the best CRT monitors available. It works for me because I’m mostly driving lower resolutions and my CRT monitor is a mid-range model. But I would need to upgrade if I bought a better CRT.

While VGA dominates by far, it’s not the only input you might find. A handful of late-model CRTs support a version of DVI-A or DIV-I, which can provide an analog signal. CRT monitors from the 1980s might use a different video input. Commodore 1701 and 1702 monitors, for example, can use a composite input (just as you’d find on a CRT television).

The fastest way to buy a CRT monitor is eBay or Etsy. Hundreds of CRT computer monitors are available, including many that fit the recommendations of this guide. You’ll have to spend several hundred dollars, however, and you can’t see the monitor before buying. Shipping is a gamble, too. Many fine CRTs have met their demise in the hands of Fedex.

Local listings like Craigslist, OfferUp, and Facebook Marketplace can help you find a more affordable monitor, but stock can be limited depending on your location. Rural readers may have to search for months or drive long distances. Try to test the CRT before you buy, especially if it’s not sold at a low price. Ask the seller to have it connected to a PC when you arrive.

Don’t neglect searching offline. I snagged my current CRT computer monitor for free from someone a few blocks away who decided to put old electronics on the curb. Yard sales and estate sales are great, too. They can be a grind if you don’t enjoy the search, but you’ll spend a lot less than you would online.

Put out the word, as well. Post on social media about your search and ask relatives if they have a hidden gem. CRT monitors aren’t easy to move or dispose of, so they’re often stuffed in a closet, attic, or basement. Many people will let you have a monitor to get it out of their hair.

Good luck on your search. Just remember: The best CRT monitor is the one you own. Don’t be too harsh on the CRTs you come across. Your first task is finding one that meets your needs and reliably works. After that, you can get picky. Once again, if you’re looking for a newer display filled with the latest and greatest goodies, our guides to the best PC monitors, best 4K monitors, and best gaming monitors can help you find the perfect fit for your needs.

Unless you’ve been following the less mainstream tech conversations going on these days, you might have missed a renewed discussion on the merits of CRT or cathode ray tube screens. Yes, we’re talking about the original ‘tube’ that has now been all but replaced by various flat panel technologies.

Believe it or not, there’s an entire generation of people who have probably never seen a CRT in real life! So why are people in tech circles talking about this older technology today? What are CRT monitors used for? Isn’t modern display tech superior?

In the early days scaled images on an LCD screen looked absolutely awful, but modern scaling solutions look great. So it’s not much of an issue anymore.

Still, images on a CRT look good at any resolution. This is because there are no physical pixels using this display technology. The image is drawn on the inside of the screen using electron beams, so no scaling is required. The pixels are simply drawn at the size they need to be. So even relatively low resolution images look nice and smooth on a CRT.

In the past this was a good way to gain performance in 3D apps and video games. Simply lower the resolution to get a smoother experience. With the advent of LCD technology you pretty much had to output at the native resolution, which meant cutting corners in other areas such as texture and lighting detail.

Using a CRT for high-end 3D applications means you can cut the resolution, keep the eye candy and get good performance. With almost no visual hit compared to doing the same thing on an LCD.

LCD flat panels use a display method known as “sample and hold”, where the current frame stays on screen in a perfectly static way until the next one is ready. CRTs (and plasma screens) use a pulsed method. The frame is drawn on screen, but immediately begins to fade to black as the phosphors lose energy.

While the sample and hold method might sound superior, the perceptual effect is a blurry image in motion thanks to the way we perceive apparent motion. Sample and hold is not the only cause of unwanted motion blur on LCDs, but it’s a big one.

Modern screens either use some form of “motion smoothing”, which leads to the dreaded “soap opera effect” or they insert black frames between the regular ones which causes brightness reduction. CRTs can show sharp motion with no brightness sacrifice and can therefore look much better when playing back video.

Due to the way LCDs work, it’s essentially impossible to display true black in an image. An LCD panel consists of the LCD itself, with its array of color-changing pixels and a backlight. Without the backlight, you won’t see the image. That’s because LCDs don’t give off any light of their own.

The problem is that when a pixel switches off to display black, it doesn’t block all the light coming from behind it. So the best you can get is a sort of grey tone. Modern LCD screens are much better at compensating for this, with multiple LEDs evenly lighting the panel and local backlight dimming, but true blacks are still not possible.

CRTs on the other hand can display blacks almost perfectly thanks to how it draws the picture on the back of the screen. Modern technologies like OLED does nearly as well, but is still far too expensive for mainstream consumers. Plasma was also very good in this regard, but has been largely phased out. So right now in 2019 the best black levels are still to be found in CRTs.

If you like consuming retro content, which includes old video games from before HD consoles and standard 4:3 aspect ratio video content, it may be best to watch them on a CRT.

Some video games actually took advantage of CRT quirks to generate effects such as flowing water or transparency. These effects don’t work or look odd on modern flat panels. Which is why CRTs are popular and sought after among retro gamers.

While there are plenty of ways in which CRTs are objectively superior to even the best modern flat panel displays, there’s also a long list of cons! After all, there’s a reason the world moved to newer display technology.

It’s also important to remember that flat panel displays at the time of the shift were far worse than those of today, yet people felt the pros of LCDs were on balance a better deal.

CRT screens are huge, heavy, power-hungry and less suitable for productivity and watching widescreen films. While their resolution limits aren’t a huge issue for video games, any sort of serious work turns into struggle with low resolution text and a lack of desktop real estate.

Despite their large size, actual screen dimensions are tiny relative to flat panels. There certainly isn’t a CRT equivalent of the 55” and larger monsters we have today. Despite the substantial image quality and motion advantages CRTs have over even the best modern flat panels, only a small niche group of people are willing to put up with the long list of drawbacks that come with CRT use.

It"s true. Running modern games on a vintage CRT monitor produces absolutely outstanding results - subjectively superior to anything from the LCD era, up to and including the latest OLED displays. Best suited for PC players, getting an optimal CRT set-up isn"t easy, and prices vary dramatically, but the results can be simply phenomenal.

The advantages of CRT technology over modern flat panels are well-documented. CRTs do not operate from a fixed pixel grid in the way an LCD does - instead three "guns" beam light directly onto the tube. So there"s no upscaling blur and no need to run at any specific native resolution as such. On lower resolutions, you may notice "scan lines" more readily, but the fact is that even lower resolution game outputs like 1024x768 or 1280x960 can look wonderful. Of course, higher-end CRTs can input and process higher resolutions, but the main takeaway here is that liberation from a set native resolution is a gamechanger - why spend so many GPU resources on the amount of pixels drawn when you can concentrate on quality instead without having to worry about upscale blurring?

The second advantage is motion resolution. LCD technologies all use a technique known as "sample and hold" which results in motion rendering at a significantly lower resolution than static imagery. Ever noticed how left/right panning in a football match looks blurrier than static shots on an LCD? This is a classic example of poor motion resolution - something that simply isn"t an issue on a CRT. Motion handling on CRT is on another level compared to modern technologies in that every aspect of every frame is rendered identically, to the point where even a 768p presentation may well be delivering more detail in motion than a 4K LCD.

Then there"s display lag, or rather, the complete lack of it. Imagery is beamed directly onto the screen at the speed of light, meaning zero delay. Even compared to 240Hz LCDs I"ve tested, the classic mouse pointer response test feels different, faster. The advantages in terms of game response - particularly with an input mechanism as precise as the mouse - need no further explanation.

On a more general level, there"s a sense that games and hardware have "grown" into CRT technology over the years. Visuals are more realistic than they"ve ever been, and there"s something about the look of a CRT presentation that further emphasises that realism - aliasing in particular is much less of an issue compared to a fixed pixel grid LCD. Secondly, PC hardware has evolved now to the point where running at higher refresh rates than 60Hz is relatively simple - and a great many CRT monitors can easily run at much faster frequencies, up to 160Hz and even beyond, depending on the display and the input resolution. This is all pretty good for a technology that essentially became obsolete soon after the turn of the millenium.

And that"s where the negatives of CRT gaming start to hit home. The technology is outdated, which presents many pitfalls. The most obvious concerns form-factor: CRT displays are big, bulky and weigh a lot. I invested in a display widely considered to be one of the greatest CRTs ever made - the Sony Trinitron FW900 - a 16:10 24-inch screen. As the video hopefully demonstrates, picture quality is immense, but so is the heft of the screen. It weighs 42kg and with a 600x550mm footprint, the amount of real estate required is not insignificant.

Then there"s the input situation. CRT monitors use VGA, DVI-I or component RGB BNC inputs - and pretty much the most powerful modern GPU still to offer support there is the GTX 980 Ti or Titan X Maxwell. Thankfully HDMI, USB-C and DisplayPort to VGA adapters are available, but you"ll be spending a lot of time online looking for the right one to handle high pixel-rates if you intend to go past 1920x1200 at 60Hz. Very few widescreen CRTs are available and even the Sony FW900 has a 16:10 aspect ratio, meaning that console gaming isn"t really a good fit for CRT displays - 4:3 screens, even less so. Yes, you can run consoles on a CRT, but my feeling is that for many reasons, this is a pursuit best suited to PC users.

Finally, there"s the cost - which can cut both ways - along with the quality of the display you"ll actually get. The FW900 is a legendary screen with massive asking prices to match. However, John Linneman"s 19-inch 4:3 Sony Trinitron G400 cost him just 10 Euros (!) and still looks amazing. However, the fact is that in both John"s case and mine, the screens weren"t in optimal condition when we bought them - which is to be expected for screens well into their second decade of life. Suffice to say, getting image quality to the expected levels can take a lot of time, effort and plenty of research. And on a more basic level, CRT screens are made of glass and glare can be an issue. In shooting the video on this page, I had to film at night in order to show the screen in the best possible light.

There are plenty of pitfalls then - but the end results while gaming are highly satisfactory. Modern titles on a CRT can look sensational, you have the benefits of high refresh rates if you want them, you can turn up all the eye candy and you don"t need to worry so much about resolution as a major defining factor of image quality. Today"s premium-priced gaming LCDs are trying very hard to recapture CRT"s major benefits - low latency, high refresh rates and reduced input lag - but as good as many of these screens are, for our money nothing beats a good old-fashioned cathode ray tube display for desktop gaming - not even the very best LCD screens on the market.

Direct exposure of bare skin to strong light after PDT can cause severe skin phototoxicity although the superficial light irradiation has a limited tissue penetration depth. Therefore, the patient is advised to avoid direct light exposure to the skin after the administration of the photosensitizer. The length of light avoidance after PDT depends on the retention time of photosensitizer in the normal skin, which can be affected by the nature and dose of photosensitizer and its administration route, and body site [

Incidences of post-PDT skin phototoxicity are often associated with patients who fail to heed the advice of strict light avoidance. Rather than indoor light, sunlight exposure shortly after receiving an exogenous photosensitizer or prodrug presents a major risk factor for skin phototoxicity. Although rare, exposure to CRT or LCD monitor emissions after PDT can also cause cutaneous phototoxicity on bare skin [

Color CRT monitors use a phosphor-coated screen. Phosphors are arranged in strips and emit visible light when exposed to an electron beam generated within the CRT. Three beams are used in CRT monitors to excite red, green, and blue color in combinations needed to create the various hues that form the picture. CRT monitors are gradually being replaced by LCD flat panel monitors in households and offices. The light emitting mechanism of LCD monitors is different than that of CRTs. LCD displays use two basic techniques for producing color: passive matrix or thin film transistor. Basically, LCD monitors utilize two sheets of polarizing material with a segmented liquid crystal solution between them. An electric current passes through the liquid causing the crystals to align so that the light emission of individual pixels can be controlled. LCD monitors are typically backlit by a white light fluorescent (fluorescent-backlit) or LED light (LED-backlit) source since the liquid crystals generate no light of their own.

This study examined the light emission profiles of common CRT, LCD, and LED monitors utilizing simulated movie and video game streams. The range of optical irradiance generated from the movie stream was broader than that from the game stream (see Fig. 2). The 50% points of the cumulative ratio for the game were slightly higher than that of the movie (see Fig. 3). Using a representative figure of 1 μW/cm2 as an example, it can be estimated that 10 min exposure to a monitor at a distance of 18 in. can deliver a total fluence of 0.6 mJ/cm2, i.e., 60 μJ/cm2/min to the skin surface. This estimated fluence rate is considerably lower than that of sunlight or PDT light, which are typically at 101–102 mW/cm2 range. The moderate monitor settings (e.g., the total emission intensity of 6:5 μW/cm2 at the measurement point), randomly selected video streams, and longer sensor-to-monitor distance (e.g., 18 in.) might cause an underestimate of the fluence rate. It should be noted that the actual light emission profiles depend on several factors, including the size and configuration of monitor screen, program being played back on the screen, and its duration. The light fluence received by the skin is also affected by the screen-to-face distance and their alignment. Furthermore, the light fluence inside the skin of a multilayered geometry can be significantly affected not only by light source but also by tissue optical properties [

For 10 min of the movie or game the integrated fluence from the CRT’s visible emission (467.5–800 nm) measured by the spectrometer at the same face position (i.e., 18 in. from the monitor) was approximately 1 mJ/cm2. This value was higher than that estimated from the optical irradiance (0.6 mJ/cm2) measured by the Si photodiode. It needs to be pointed out that the Si photodiode used in this study is wavelength dependent. As the wavelength was set up at 635 nm, it might underestimate the actual total optical irradiance. Interestingly, under the same condition, the integrated fluence from the LCD or LED was 40% or 80% higher than that of the CRT. The active diagonal screen size of the CRT, LCD, and LED was 16, 15, and 17.2 in., respectively. Under the white screen mode, the relative fluence of visible emission from the LCD or LED was 40% or 60% higher than that of the CRT when the total emission intensity was set up at the same level (see Fig. 1). Although the difference in the screen size might contribute to some variation, this finding suggests that the common assumption that LCD and LED monitors might be safer than older CRT monitors is incorrect in terms of potential risk of skin phototoxicity.

In some cases, the back of the hands can be exposed to monitor light while working on the keyboard. A recent report indicated that mild phototoxicity could occur on the back of both hands after PDT when the hands were exposed to an LCD monitor for a few hours [

It has been a concern that overexposure to UV and visible radiation in the presence and absence of photosensitizer might be also detrimental to the eye and subsequently to vision [

In summary, our results suggest that the optical and spectral profiles of emissions from color monitors are clinically relevant. Therefore, prolonged exposure to monitor emissions at a close distance might pose as a potential risk to the face, eyes, and hands. Future guidelines on post-PDT care and patient warnings should include the avoidance of overexposure to common light sources, such as computers, video games, and TV monitors after receiving a topical and systemic administration of a photosensitizer. This should be emphasized to certain high-risk patient populations, e.g., teenagers who may play video games for extended periods of time and people who receive repeated topical application of a photosensitizer or prodrug at a short period of time or work long hours in front of a large and bright monitor screen. The same caution is also applicable to patients who take drugs known to cause photoallergic, photosensitive, and phototoxic reactions.

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Associated DataThe empirical experiment was preregistered. The preregistration, as well as all data, analysis scripts, and experimental materials are available at (https://osf.io/g842s/).

Liquid crystal display (LCD) monitors are nowadays standard in computerized visual presentation. However, when millisecond precise presentation is concerned, they have often yielded imprecise and unreliable presentation times, with substantial variation across specific models, making it difficult to know whether they can be used for precise vision experiments or not. The present paper intends to act as hands-on guide to set up an experiment requiring millisecond precise visual presentation with LCD monitors. It summarizes important characteristics relating to precise visual stimulus presentation, enabling researchers to transfer parameters reported for cathode ray tube (CRT) monitors to LCD monitors. More importantly, we provide empirical evidence from a preregistered study showing the suitability of LCD monitors for millisecond precise timing research. Using sequential testing, we conducted a masked number priming experiment using CRT and LCD monitors. Both monitor types yielded comparable results as indicated by Bayes factor favoring the null hypothesis of no difference between display types. More specifically, we found masked number priming under conditions of zero awareness with both types of monitor. Thus, the present study highlights the importance of hardware settings for empirical psychological research; inadequate settings might lead to more “noise” in results thereby concealing potentially existing effects.

With modern display technology becoming increasingly advanced, bulky cathode ray tube (CRT) monitors are (with few exceptions) no longer being produced. Instead, flat panel technologies have become the de-facto standard and among those, liquid crystal display (LCD) monitors are most prevalent. This technological change has also affected experimental research relying on computerized presentation of stimuli. Based on decades of experience with CRT monitors, their characteristics are well known and they have proven to provide reliable and precise stimulus presentation

The present paper summarizes the current knowledge base regarding important differences between CRT and LCD monitors; it aims to provide a hands-on guide for the setup of computer experiments using LCD monitors in a manner that yields reliable presentation times and CRT-comparable results. Additionally, we provide empirical evidence from a masked priming task and a prime-discrimination task, demonstrating that current-generation LCD monitors can be used for masked visual stimulus presentation.

First, we will provide a brief technical overview of functional principles as they relate to visual stimulus presentation. Detailed descriptions and parameter measurements are already available from the existing literature; however, our intention here is to equip readers with limited technical expertise with the necessary knowledge to set up computer experiments with LCD monitors. Thus, we keep our explanations relatively short and simplified.

LCD monitors work differently: Each pixel consists of liquid crystal threads that can be twisted or arranged in parallel by an electrical current applied to them. This leads to a polarization effect that either allows or prevents light passing through. A white light source located behind this crystal array uniformly and constantly illuminates the array. To display a black pixel, the crystal threads are twisted by 90° such that no light will pass through. A white pixel is achieved by aligning the crystals such that maximum light is allowed to pass through, until a different, non-white color needs to be displayed (see the lower panel of Fig. 1 for an LCD pixel’s brightness over time). This is a static process, not a pulsed one as in CRTs.

In theory, the difference in presentation methods, namely a strobing versus a static image, should be of no consequence if the light energy that falls onto the retina remains the same over the time period of one single frame. As the Talbot-Plateau law states2 is equally well detectable as a light flash presented for 60 ms at 40 cd/m2. This suggests that temporal integration can be easily described by energy summation”. Thus, in principle, LCD and CRT monitors should be able to yield comparable results.

However, due to the differences in technology, the visual signals produced by the two display types have different shapes (i.e., a different light energy-over-time-curve; see Fig. 1). Moreover, default luminance as well as visual-signal response times (in addition to other parameters, see below) differ between most CRT and LCD monitors

Table 1 reports the parameters we considered in setting up the CRT and LCD monitors. Certainly, most of them are commonly considered when setting up a computer experiment; nevertheless we deemed it important to mention them here explicitly, as their neglect might have unintended consequences. We used a 17” Fujitsu Siemens Scenicview P796-2 CRT color monitor previously used in several published studies including studies with masked presentation conditions

FeatureDescriptionRecommendationCommentExperiment settingLCD panel typeIPS (in-plane switching): true-color and contrast less dependent on viewing angle, slower response time;

Native resolution, screen diagonal, and aspect ratioWith constant screen diagonal and aspect ratio: The higher the resolution, the smaller objects and stimuli that are measured in pixels appear on the screen.To achieve results as close as possible to a CRT experiment, calculate the size (e.g., in mm) of one native pixel and resize the stimuli if necessary, so that the real size (in mm) on the CRT corresponds to the real size on the LCD.Take the aspect ratio into account to avoid distortions like they would appear when a resolution with an aspect ratio of 4:3 (e.g., 1024 * 768) is applied to a monitor with a native aspect ratio of 16:9 (e.g., native resolution of 1920 * 1080). If you need to do the latter, consider letterboxing.In the present study, CRT resolution was 1024 * 768 (visible area 324 * 243 mm, aspect ratio 4:3), diagonal 17”, dimensions of 1 pixel: 0.316 * 0.316 mm. LCD resolution was 1024 * 768 (visible area 531 * 299 mm, aspect ratio 16:9, dimensions of 1 pixel (letterboxed to 4:3) was 0.389 * 0.389 mm). LCD stimulus size thus needed to be enlarged by a factor of 1.23. Stimuli were adjusted to match sizes.

Monitor brightness (as can be set in the monitor’s user menu)Provides the same amount of radiated energy in a single frame compared to CRTs.Measure the brightness of a used (and warmed up) experimental CRT with a luminance meter with both a completely black and a completely white screen. Try to match both values with the LCD.When an exact match is not possible, try to adjust the monitor’s contrast setting accordingly (i.e., usually downregulate the LCD).In the present study, CRT settings used an on-screen-display brightness setting of 100%; LCDs were set to 9%.

Refresh rateMultiple complex effects are dependent on the choice of the correct refresh rate, particularly the multiples of the presentation time of a single frame.Choose the refresh rate to match your CRT or, when designing a new experiment, to match your desired stimulus presentation times as closely as possible.Example: Stimulus presentation 30 ms; typical refresh rates are 60, 70, 100, 120, 144 Hz. Possible choices are two frames of 60 Hz = 2 * (1/60) = ca. 33 (ms). A better choice would be three frames of 100 Hz = 3 * (1/100) = 30 (ms).The experiment in the present study used a refresh rate of 100 Hz with presentation times consisting of multiples of 10 ms.

We tested various monitor user settings, refresh rates, resolutions and luminance settings (see materials available at https://osf.io/g842s/) with regard to the emitted light energy–over-time-curve and therefore response characteristics (i.e., onset and offset of full screen and centrally presented stimuli). Measurements were conducted with a photodiode setup, using both an oscilloscope (model “Agilent MSOX 3012 A”) and a self-developed microcontroller setup as measurement devices. Stimuli were black and white squares.

Our measurements revealed several interesting characteristics: First, luminance of the LCD monitor at default setting (i.e., maximum brightness) exceeded the CRT luminance at a ratio of 3.25:1. However, comparable average luminance can be (and was) achieved by downregulating the LCD monitor (the older CRT technology emits less energy even at maximum settings, see Table 2), without participants perceiving it as unnaturally dark. If one plans to upgrade from CRT to LCD monitors in an experimental laboratory, we therefore recommend measuring the CRT monitors’ brightness levels and matching them in the new LCD monitors’ user setup, if comparability with the old setup is needed. This will minimize hardware-dependent variability, thus contributing to better replicability. Please note that a brightness adaption is not a necessary precondition when employing LCD monitors; researchers should simply be aware that the brightness level can have an influence onto the resulting effects, especially in time-critical experiments with short and/or masked presentation. Thus, we recommend the adaptation for time-critical experiments in which researchers orient on existing empirical evidence gathered with CRT monitors. Furthermore, gray-to-gray response times varied slightly depending on the employed brightness levels2), so we suggest that researchers can rely on this more efficient method as an approximation.

Note. Brightness refers to monitor menu settings, cd/m² was measured with the luminance meter and also calculated from the measured voltage (i.e., via oscilloscope). The voltage function matches the values measured with the luminance meters almost perfectly.

For the empirical comparison of human performance with CRT and LCD monitors, we relied on these results and set the monitor settings accordingly (see Method section below).

Participants were administered a masked number priming task and a subsequent forced-choice prime discrimination task using both a CRT and an LCD monitor. In this well-established paradigm

Of central interest was the question whether both monitors would yield comparable masked priming effects. Monitors were set according to the parameters described in the previous section (see also Method section below). In order to obtain conclusive evidence, we decided for sequential hypothesis testing using Bayes factorshttps://osf.io/g842s/.

As we aimed to find evidence for or against monitor type differences in priming, we applied sequential hypothesis testing with Bayes factors (BF), which allow quantification of evidence both for and against a null hypothesisn = 24 was collected (see preregistration), we continued data collection until the preregistered BF (with JSZ prior r = 1) was reached. Specifically, data collection was stopped after the BF reached either (a) BF01 > 6 in favor of the null hypothesis of no difference in priming effects for CRT and LCD monitors, or (b) BF10 > 6 in favor of the alternative hypothesis that there is a difference between CRT and LCD monitors. We computed the BF after each day of data collection, and the critical BF was reached after testing 68 participants.

Participants were non-psychology students from Saarland University (40 females, 25 males; age Md = 25 years, range: 18–36), who were compensated with €8. Participants gave written informed consent before the study, and were free to withdraw from the study at any point in time. Anonymity of data was ensured, and treatment of subjects was in accordance with the Declaration of Helsinki. According to the guidelines of the German Research Association (Deutsche Forschungsgemeinschaft; DFG), no ethical approval was needed for this study (http://www.dfg.de/foerderung/faq/geistes_sozialwissenschaften/index.html) because it did not pose any threats or risks to the participants and participants were fully informed about the objectives of the study. The chairman of the Ethics Committee of the Faculty of Empirical Social Sciences of Saarland University confirmed that ethical approval was not needed for this study.

The experiment was a replication of Kunde et al. 2003, Exp.1et al.’s experiment). Participants’ task was to classify one-digit target numbers as smaller or greater than 5. Preceding the targets, sandwich-masked number primes were presented. The basic design of the priming task was a 2 (prime: smaller/greater than 5) × 2 (target: smaller/greater than 5) × 2 (monitor type: CRT vs. LCD) within-participants design. Following Kunde et al.et al.et al. did not find an impact of these factors on the congruency effect; they were, however, included for replication purposes (As a side effect, Kunde et al. found an interaction of notation match x congruency x prime novelty indicating small differences in masking efficiency due to greater/smaller overlap in prime-target shape; we also found such an effect, see below).

We used two 17” Fujitsu Siemens Scenicview P796-2 CRT color monitors and two 24” ViewSonic VG2401mh TFT monitors, all set to a resolution of 1024 × 768 pixels, and a refresh rate of 100 Hz . Luminance on both monitors was set to 110 cd/m² (using the luminance meter model “Gossen Mavo-Monitor USB”). The room was completely dark (i.e., measured background luminance was less than 0.5 cd/m²). Stimulus presentation and measurement of response latencies were controlled by E-Prime version 2.0 run on a DELL PRECISION T1600 computer. Participants gave their responses with a standard QWERTZ keyboard connected via PS/2. They sat at a distance of approx. 60 cm to the monitor. Distance to the monitor and viewing angle were measured at the beginning of each task (i.e., with each monitor change) and visually monitored by the experimenter in regular intervals.

Up to two individuals participated concurrently, separated by partition walls. Participants were randomly assigned to a monitor order (CRT or LCD first), and switched monitors twice, that is, they first completed the priming task on monitor 1, then the same priming task on monitor 2 [or vice versa]. Afterwards, they switched again to monitor 1 for the prime discrimination task, and then executed the prime discrimination task again at monitor 2 [or vice versa]).

The trial sequence was as follows: First, a fixation cross was displayed for 30 frames (i.e., 300 ms), followed by a pre-mask presented for seven frames (i.e., 70 ms), the prime presented for three frames (i.e. 30 ms), and a post-mask for seven frames (i.e., 70 ms; SOA = 100 ms). The post mask was immediately followed by the target, which was presented for 20 frames (i.e., 200 ms), followed by a blank (black) screen for 200 frames (i.e., 2,000 ms), which signaled the response deadline. Response keys were the ‘f’ and ‘j’ keys on a standard German QWERTZ keyboard, marked with blue stickers. If a response was given, immediate feedback (“Richtig!”/“Falsch!”; i.e., “Correct!”/“Wrong!”) was provided. After an inter-trial-interval of 800 ms, the next trial started. Figure 2 depicts an example trial.

At the beginning of the experiment, participants were informed that the experiment was investigating the differences between CRT and LCD computer monitors and that they were therefore asked to work on a simple number-categorization task using different monitors. They were instructed to categorize the presented numbers as quickly and accurately as possible. They were not informed about the primes. To familiarize participants with the procedure, they first received a practice block of 32 trials. The actual experiment consisted of five blocks of 128 trials each. After each block, participants were free to take a short break.

Mean response latency for correctly categorized targets was the dependent variable of interest. Data preparation and analysis were done as preregistered, that is, trials with reaction times below 150 ms or more than 3 interquartile ranges above the third quartile or below the first quartile of the individual distribution were discarded (1.06% of all trials), as were trials with incorrect responses (M = 6.48%, SD = 4.42%, range from 1.09% to 20.39%). Table 3 shows mean reaction times and error rates across conditions.

In the following, we present the Bayes factors based on sequential hypothesis testing as preregistered (computed with JASP, version 0.10.2), alongside results of conventional null-hypothesis significance testing (NHST) on the final sample (conducted with SPSS, version 26) to allow comparison with the original results of Kunde et al.N = 65 provided sufficient power to detect effects of dZ = 0.35 (i.e., between small and medium size according to

As our central hypothesis regarded the (lack of) priming differences between monitor types, we first present the Bayesian analysis assessing the interaction of priming condition (congruent, incongruent) and monitor type (CRT vs. LCD).

The final BF01 for the interaction of priming condition and monitor type was BF01 = 7.47; this means that the data are approx. 7.5 times more likely under the null, and thus represents moderately strong evidence for the hypothesis that the two monitor types produced equivalent masked priming effects. The evolution of the BF01 can be seen in Fig. 3. Overall there was also strong evidence for the presence of a small priming effect (M = 1.92 ms, SD = 4.15 ms, dZ = 0.46) with BF10 = 46.62.

The 2 (priming condition: congruent vs. incongruent) × 2 (monitor type: CRT vs. LCD) × 2 (notation match: match vs. non-match) × 2 (prime novelty: practiced vs. unpracticed primes) repeated measures ANOVA yielded significant main effects of priming condition, F(1,64) = 13.82, p < 0.001, ηp2 = 0.178 (dz = 0.46), monitor type, F(1,64) = 99.11, p < 0.001, ηp2 = 0.608 (dz = 1.23), and notation match, F(1,64) = 5.33, p = 0.024, ηp2 = 0.077 (dz = 0.29). Furthermore, a significant three-way-interaction of priming condition × monitor type × notation match emerged, F(1,64) = 7.00, p = 0.010, ηp2 = 0.099 (dz = 0.33). No further results were significant (for the sake of interest: priming condition × prime novelty, F(1,64) = 2.55, p = 0.115, ηp2 = 0.038 (dz = 0.20); priming condition × notation match, F(1,64) = 2.16, p = 0.147, ηp2 = 0.033 (dz = 0.18); priming condition × monitor type × notation match × prime novelty, F(1,64) = 2.77, p = 0.101, ηp2 = 0.042(dz = 0.21)). We also checked for a possible effect of monitor order; no effects emerged. Please note that the main effect of monitor largely reflects the DCC input lag (see Introduction), that is, the recorded response times are larger for the LCD monitor, because the internally recorded stimulus onset time is earlier than it actual was due to the input lag.

We followed up the significant three-way interaction with separate ANOVAs for each monitor type. The repeated measures ANOVA for the LCD monitor yielded a significant priming condition × notation match interaction, F(1,64) = 8.16, p = 0.006, ηp2 = 0.113 (dz = 0.35), while the interaction was not significant for the CRT monitor, F(1,64) = 0.58, p = 0.45, ηp2 = 0.009 (dz = 0.09). In the LCD monitor analysis, prime-target combinations with non-matching format yielded a congruency effect, t(64) = 4.54, p < 0.001, dZ = 0.56, while matching prime-target combinations did not yield a congruency effect, t(64) = 0.22, p = 0.83, dZ = 0.03. It is likely that differences in masking efficiency were responsible for this finding (i.e., stimuli matching in format mask each other better), as Kunde et al.

The signal detection index d’ served as the dependent variable in the prime-recognition task. In a first analysis, d’ was tested against zero with a repeated-measures MANOVA, with monitor type as a within-participants factor. The constant test of this MANOVA was not significant, F(1,64) = 0.01, p = 0.94, ηp2 = 0.000 (dz = 0.01), indicating overall chance performance. The main effect of monitor type was also not significant, F(1,64) = 0.59, p = 0.45, ηp2 = 0.009 (dz = 0.10), indicating zero awareness with both monitor types (d’CRT = 0.004; d’LCD = −0.005).

A repeated measures ANOVA with notation (Arabic vs. verbal), prime novelty, and monitor type as within-participants factors yielded a notation × prime novelty interaction as the sole significant effect, F(1,64) = 6.20, p = 0.015, ηp2 = 0.088 (dz = 0.31). Practiced digits were recognized better than unpracticed digits (d’prac_digits = 0.021; d’unprac_digits = −0.009), t(64) = 1.97, p = 0.05, dZ = 0.24, while there was no such effect for number words, t(64) = 1.80, p = 0.08, dZ = 0.22 (d’prac_words = −0.019; d’unprac_words = 0.006). Indeed, recognition was different from chance performance for practiced digits, t(64) = 2.16, p = 0.034, dZ = 0.25, but not for any other item type, ts < 1.

The present paper contributes in important ways to empirical investigations of effects that necessitate millisecond-precise timing, such as the masked priming effects inspected in this paper. We laid out important differences between CRT and LCD technology, and provided guidelines on how to configure a current-generation LCD monitor to achieve results comparable to those obtained with a CRT monitor. Thus, our paper may help researchers establish adequate conditions to conduct such experiments with the precision needed, using state-of-the-art technology. Empirically, we demonstrated that experiments requiring precise timing—in this case a masked priming experiment—can yield comparable effects using CRT and LCD monitors. Specifically, we found comparable masked number priming effects using CRT and LCD monitors under conditions of zero prime awareness (with the exception of the practiced digits condition), as assessed with a separate forced-choice prime discrimination task. Thus, we replicated and extended the findings of Kunde et al.

First of all, the present paper shows that current-generation LCD monitors can be used for millisecond-precise presentation, even under masked presentation conditions. To this end, we used a twisted nematic (TN) panel, enabled DCC, used high-contrast stimuli, and adjusted the luminance of the LCD screen to yield a result comparable to a CRT monitor, given a predetermined stimulus presentation time. As we outlined extensively in the theoretical introduction, and as already stated by several other authors

Regarding our empirical findings, we found, as hypothesized, significant and comparable masked number priming effects using both CRT and LCD monitors under conditions which yielded (for all except one condition) zero awareness in a subsequent forced-choice prime discrimination task. The Bayes factor evaluating a difference in priming effects between CRT and LCD monitors—the preregistered main hypothesis that provided the basis for data sampling—indicated strong evidence for the null hypothesis. Thus, the present results show that LCD monitors are suited for research requiring millisecond-precise timing, and that such research can yield comparable results to those obtained with a CRT monitor if luminance is matched and settings are chosen appropriately.

To summarize, the present empirical results showed that LCD monitors can be used for research requiring millisecond-precise timing, which can yield results that are comparable to those obtained from research conducted with CRT monitors, if settings are chosen appropriately. Our study thus highlights the importance of considering the effects of technological setup on empirical research. We hope that researchers in the field can use the recommendations we provided to achieve high precision in visual stimulus presentation.

We thank Kilian Leonhardt for his help in measuring the signal shapes of the CRT and LCD monitors and for providing the measurement device. We thank Felix Kares and Tatiana Koeppe for their help in data collection, and Ullrich Ecker for his comments on an earlier draft of the manuscript.

M.R. conceived and designed the study, analyzed the human performance data, prepared the figures and tables belonging to the human performance data and wrote the main manuscript text. She also prepared all materials which are online available at OSF. A.W. configured the LCD and CRT monitors as well as the computers, did the hardware measurements, programmed the study, wrote some of the corresponding paragraphs in the manuscript and prepared the figures and tables related to the hardware settings.

The empirical experiment was preregistered. The preregistration, as well as all data, analysis scripts, and experimental materials are available at (https://osf.io/g842s/).

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Cathode Ray Tube (CRT) monitors are the most toxic to our environment. Each monitor contains large amounts of lead, along with phosphorous, cadmium, and mercury. Disposal can be quite hazardous if one of the glass tubes breaks and ejects those toxins into the air.

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A cathode-ray tube (CRT) is a vacuum tube containing one or more electron guns, which emit electron beams that are manipulated to display images on a phosphorescent screen.waveforms (oscilloscope), pictures (television set, computer monitor), radar targets, or other phenomena. A CRT on a television set is commonly called a picture tube. CRTs have also been used as memory devices, in which case the screen is not intended to be visible to an observer. The term

In CRT television sets and computer monitors, the entire front area of the tube is scanned repeatedly and systematically in a fixed pattern called a raster. In color devices, an image is produced by controlling the intensity of each of three electron beams, one for each additive primary color (red, green, and blue) with a video signal as a reference.magnetic deflection, using a deflection yoke. Electrostatic deflection is commonly used in oscilloscopes.

A CRT is a glass envelope which is deep (i.e., long from front screen face to rear end), heavy, and fragile. The interior is evacuated to 0.01 pascals (1×10−7 atm)×10−12 atm) or less,implosion that can hurl glass at great velocity. The face is typically made of thick lead glass or special barium-strontium glass to be shatter-resistant and to block most X-ray emissions. CRTs make up most of the weight of CRT TVs and computer monitors.

Since the mid-late 2000"s, CRTs have been superseded by flat-panel display technologies such as LCD, plasma display, and OLED displays which are cheaper to manufacture and run, as well as significantly lighter and less bulky. Flat-panel displays can also be made in very large sizes whereas 40 in (100 cm) to 45 in (110 cm)

Cathode rays were discovered by Julius Plücker and Johann Wilhelm Hittorf.cathode (negative electrode) which could cast shadows on the glowing wall of the tube, indicating the rays were traveling in straight lines. In 1890, Arthur Schuster demonstrated cathode rays could be deflected by electric fields, and William Crookes showed they could be deflected by magnetic fields. In 1897, J. J. Thomson succeeded in measuring the charge-mass-ratio of cathode rays, showing that they consisted of negatively charged particles smaller than atoms, the first "subatomic particles", which had already been named George Johnstone Stoney in 1891. The earliest version of the CRT was known as the "Braun tube", invented by the German physicist Ferdinand Braun in 1897.cold-cathode diode, a modification of the Crookes tube with a phosphor-coated screen. Braun was the first to conceive the use of a CRT as a display device.

The first cathode-ray tube to use a hot cathode was developed by John Bertrand Johnson (who gave his name to the term Johnson noise) and Harry Weiner Weinhart of Western Electric, and became a commercial product in 1922.

In 1926, Kenjiro Takayanagi demonstrated a CRT television receiver with a mechanical video camera that received images with a 40-line resolution.Philo Farnsworth created a television prototype.Vladimir K. Zworykin.: 84 RCA was granted a trademark for the term (for its cathode-ray tube) in 1932; it voluntarily released th