Video Artifacts

Lens system

A photographic objective is a coordinated optical system rather than one ideal element. Its glass, air gaps, aperture, coatings, and moving groups form the image together—and introduce different families of artifacts along the way.

Simplified photographic lens systemLight travels from the scene through front surfaces, several shaped glass elements, an aperture stop, and a moving focus group before reaching the image plane.01020304Object pointImage planeLens barrel
  1. 01SurfacesInterfaces, coatings, contamination
    • Lens flare
    • Ghosting
    • Surface contamination
  2. 02ElementsShape, glass, spacing, alignment
  3. 03ApertureOpening, blades, diffraction
    • Defocus
    • Aperture bokeh
    • Diffraction stars
  4. 04Focus & coverageMoving optics, image circle, field angle
    • Focus breathing
    • Natural falloff
    • Mechanical vignetting
    • Field curvature