Lens MTF Curves & Optical Aberrations: Spherical, Coma, Astigmatism & Chromatic Distortion

Modulation Transfer Function (MTF) curves represent the objective optical benchmark for measuring a camera lens's ability to resolve fine detail and maintain contrast.

1. Reading Modulation Transfer Function (MTF) Charts

• 10 line pairs per millimeter (lp/mm): Evaluates overall coarse contrast and punch. Curves above 0.8 indicate exceptional optical clarity.
• 30 line pairs per millimeter (lp/mm): Evaluates micro-detail resolving power (eyelashes, fabric weave). Curves above 0.6 indicate outstanding sharpness.
• Sagittal (Solid Line) vs. Meridional (Dashed Line): Divergence between these curves measures astigmatism and lateral color fringing toward image corners.
• Diffraction Sweet Spot: Most prime lenses achieve peak optical MTF performance between f/5.6 and f/8 before wave diffraction blurs resolution at f/16–f/22.