A CRT monitor is a display that uses a cathode ray tube to produce images by firing beams of electrons at a phosphor-coated glass screen. These bulky, heavy screens were the standard for televisions and computer monitors from the mid-20th century until flat-panel LCDs replaced them in the 2000s. While no longer manufactured at scale, CRTs remain relevant to retro gaming enthusiasts, video professionals, and anyone curious about the technology that powered screens for decades.
How a CRT Creates an Image
At the back of every CRT monitor sits an electron gun, a heated cathode that generates a continuous stream of electrons. These electrons are accelerated toward the front of the tube by a positively charged anode, reaching high speeds inside a sealed glass vacuum. Without the vacuum, air molecules would scatter the electrons before they ever reached the screen.
Deflection coils surrounding the tube use magnetic fields to steer the electron beam horizontally and vertically, sweeping it across the screen in a precise pattern. The beam scans left to right, line by line, from the top of the screen to the bottom. At 60 Hz, a CRT draws one complete frame in 16.7 milliseconds, then starts over. When those fast-moving electrons hit the phosphor coating on the inside of the glass, the phosphors glow briefly, producing the light you see. The color and brightness of each spot depend on which phosphors are struck and how intensely.
Color CRTs and the Shadow Mask
Black-and-white CRTs use a single electron gun and a uniform phosphor coating. Color CRTs are more complex, using three electron guns (one each for red, green, and blue) that fire simultaneously. A thin perforated metal sheet called a shadow mask sits just behind the screen, ensuring each beam hits only its corresponding color of phosphor dot. The combination of red, green, and blue phosphors at varying intensities creates the full range of visible colors.
Some higher-end monitors, most famously Sony’s Trinitron line, replaced the shadow mask with an aperture grille: a series of fine vertical wires instead of a perforated sheet. The wires could be spaced closer together than shadow mask perforations, allowing finer detail and brighter images. Aperture grilles also handled heat better. A shadow mask expands outward when displaying bright images, which can distort color alignment. Aperture grille wires expand only vertically, so the image stays stable.
Strengths That Still Matter
CRT monitors have qualities that modern displays have only recently matched, and in some cases still haven’t. The most notable is motion clarity. Because CRT phosphors glow briefly and then fade before the next scan, the display doesn’t “hold” an image the way an LCD panel does. This means virtually no motion blur or ghosting, a characteristic that makes fast-moving content look exceptionally sharp.
Input lag is another area where CRTs earned their reputation. Using the industry-standard measurement, a 60 Hz CRT has about 8.3 ms of input lag (the time for a full frame to be drawn). But the raw processing delay, the actual time the display adds beyond what the signal provides, is essentially zero. Modern LCD monitors add roughly 2 ms of raw processing lag on top of their frame time, which means the practical difference is small today. A decade ago, though, CRTs held a meaningful advantage, and competitive gamers noticed.
CRTs also handle multiple resolutions gracefully. Because the electron beam can be directed anywhere on the screen, a CRT doesn’t have fixed pixels the way an LCD does. Running a lower resolution on a CRT simply changes the scanning pattern rather than forcing the display to scale the image, so non-native resolutions look natural instead of blurry.
Common Problems and Limitations
CRT monitors came with a long list of practical drawbacks. They were enormous and heavy, with a deep glass tube extending far behind the screen. A 19-inch CRT could easily weigh 50 pounds or more. The curved glass on most models introduced geometric distortion: images could appear bowed, pinched, or unevenly sized across different parts of the screen. Flat-screen CRTs reduced this curvature but were actually more prone to geometry issues like pincushion distortion, where the edges of the image curve inward.
Screen flicker was another persistent issue. At lower refresh rates (60 Hz, common for many setups), the phosphors would visibly pulse, causing eye strain during extended use. Running at 75 Hz or higher reduced flicker significantly, but not all hardware supported faster refresh rates at every resolution. Convergence errors, where the three color beams fail to align perfectly, could produce color fringing around text and fine details. Over time, the magnetic components inside a CRT could drift, worsening these problems.
Radiation and Safety
CRTs produce X-rays as a byproduct of electrons striking surfaces inside the vacuum tube at high voltage. This raised public concern for years, but the actual risk has always been minimal. The FDA established a federal standard in 1969 limiting X-ray emissions from TV receivers to 0.5 milliroentgens per hour, and manufacturers have met that standard since 1970. In practice, most CRT sets emit no measurable radiation at all. The leaded glass in the tube’s funnel section (which contains 15 to 34 percent lead by weight) serves as built-in shielding, and modern electronic safety circuits further eliminate risk.
Power and Environmental Costs
CRTs consume considerably more electricity than flat-panel displays. The electron guns, deflection systems, and high-voltage circuits all draw significant power. Replacing CRTs with LCD and LED screens has been one of the largest single sources of energy savings in consumer electronics.
Disposal is the bigger environmental concern. The lead content in CRT glass is substantial. The funnel and neck portions contain 15 to 34 percent lead by weight, and the frit (a thin seal joining the front panel to the funnel) is 70 to 85 percent lead. This makes CRTs hazardous waste in most jurisdictions. They can’t legally go into standard landfills in many areas and require specialized recycling to recover and contain the lead safely.
When Production Ended
The transition away from CRTs happened gradually through the 2000s. Hitachi stopped CRT production in 2001. Sony shut down its Japanese CRT factories in 2004, with its professional broadcast monitor line (the BVM and PVM series, prized by video editors) ending production in 2008. Samsung SDI continued until 2012. The last large-scale manufacturer, Videocon, ceased CRT production in 2015, effectively marking the end of the technology’s commercial life.
Why People Still Seek Them Out
Despite being out of production for years, CRT monitors have a dedicated following. Retro gaming is the primary driver. Older consoles from the 1980s and 1990s were designed around CRT characteristics, including the way scanlines, phosphor glow, and analog signal handling affected the final image. Playing these games on a CRT produces the look and responsiveness their developers intended, while running them on a modern flat panel often introduces scaling artifacts and slight input delay.
Professional video editors who work with standard-definition content also value CRTs for their accurate color reproduction and ability to display interlaced video natively. Sony’s PVM and BVM broadcast monitors, in particular, have become collector’s items, with prices for well-maintained units climbing steadily as the remaining supply shrinks and components age out of service.