Bringing back the graphics of old games as we remember them

Have you ever felt that the graphics in old-school games looked better than they do now? That feeling was real! The reason lies in the era of CRT monitors, which has passed, giving way to modern LCDs that gave us a lot—but also took something important away.

CRT monitors generated images by scanning the inner surface of the screen, coated with phosphor, using an electron beam. This beam "drew" the picture line by line, which is why CRTs had their own refresh rates. At low refresh rates, visible flicker would occur. While it could cause eye strain, it also added distinct visual effects that made games more pleasing to the eye.

Natural smoothing and image softness

The electron beam didn’t produce clearly defined square pixels like LCDs do. Instead, it created blurred, “analog” patches of light. Combined with the physical depth of the tube and the screen’s curved shape, this led to natural optical smoothing: pixels blended together visually, making the image softer, more integrated, and organic.

Positive effect for games: It helped mask low resolution and reduced pixel “jaggies” on sprites and 3D objects, giving them a more harmonious, cohesive look. Many artists designed graphics with this display behavior in mind. What may look “pixelated” today once appeared as a complete, visually unified scene.

Motion blur as a built-in feature

Due to phosphor persistence and line-by-line scanning, CRTs naturally produced a motion blur effect during movement.

Positive effect for games: In fast-paced genres—like shooters or racing games-this blur enhanced the sense of speed and made motion appear smoother, helping to conceal stutter caused by low framerates. Some developers even used this as a visual trick to mask low FPS.

So what can we do?

No, you don’t need to buy a bulky old CRT monitor just for nostalgia. Fortunately, there are free tools that simulate many of these effects on modern displays. One such program is ShaderGlass (available on Steam and GitHub).

What ShaderGlass Does

ShaderGlass overlays shaders onto any window or application on your computer — whether it's an emulator, game, video, or even the desktop itself. Think of it as a virtual lens or filter that you look through.

Key Features:

• CRT screen simulation: Add effects like scanlines, screen curvature, blur, phosphor glow, aperture grille, shadow mask, and more.

• Flexible customization:

  • Image scaling (integer scaling)

  • Custom shaders and overlays

  • Supports ReShade/RetroArch shaders (GLSL/Slang)

• Compatibility: Works with most windowed applications on Windows — including emulators (like RetroArch, Mednafen) and older games.

• Transparent overlay: ShaderGlass creates a transparent window that displays the shader effects on top of another window, without modifying the original app.