Achieving a perfect widescreen experience on the Dolphin Emulator requires a multi-step approach because the original GameCube version was rendered in a 16:9 aspect ratio within a 4:3 frame, resulting in significant letterboxing. Understanding the RE4 Letterbox Problem
If you are still seeing minor issues or want a more native feel: resident evil 4 dolphin widescreen fix
Note: While this stretches the image to fill the sides, Leon and the environment will appear horizontally squashed because of the original game's vertical letterboxing. Step 2: Use the Zoom Widescreen Shader (Recommended) Achieving a perfect widescreen experience on the Dolphin
This vertically stretches the image, removing the top/bottom black bars and restoring proper proportions. Step 3: Advanced Optimization (Optional) Step 3: Advanced Optimization (Optional) The most effective
The most effective way to fix the aspect ratio distortion is to use a post-processing shader that "zooms" the image vertically to match the horizontal stretch.
Open a text editor (like Notepad), and paste the Zoom Widescreen Shader code found on the Dolphin Forums. Save the File: Save it as RE4.glsl .
Place this file in your Dolphin installation directory under Sys/Shaders . Activate in Dolphin: