Optical | Lens design, angle of light entry | Most pronounced at wide apertures, common in fast prime lenses | Use a narrower aperture (higher f-number) |
Mechanical | Physical obstructions like lens hoods, filters, or accessories | Shadows block light, causing darkened corners | Use the correct lens hood and avoid stacking filters |
Pixel | Center pixels receive light directly, edge pixels receive light at a steeper angle | More pronounced in smaller sensors, unaffected by aperture changes | Use software correction in post-processing |
Artificial | Intentionally added during post-processing for aesthetic effect | Deliberately added using editing software | Use Post-Crop Vignetting slider in Lightroom or Lens Correction filter in Photoshop |