MTF Analyzer

Analyze the Modulation Transfer Function of an image sensor system, combining pixel aperture, optical diffraction, and defocus contributions to understand spatial resolution limits.

MTF Analyzer

Interactive Modulation Transfer Function analyzer. Explore how pixel aperture and diffraction optics limit spatial resolution.

Pixel Pitch: 1.00 μm

f-number: f/2.8

Wavelength: 550 nm

Show components

Nyquist

500 lp/mm

Optical Cutoff

649 lp/mm

MTF@Nyquist

8.1%

MTF@Nyquist/2

47.0%

MTF Curves

Bar Target Simulation

Shows how contrast degrades at increasing spatial frequencies. Each group shows bars at a fraction of the Nyquist frequency.

Physics

The MTF describes how faithfully a system reproduces spatial detail at each frequency. For a sensor, the total MTF is the product of individual contributions:

MTF_total(f) = MTF_pixel(f) x MTF_optics(f)

Components

• Pixel aperture MTF = |sinc(f x pitch)| — the finite pixel size acts as a spatial averaging filter. Smaller pixels preserve higher frequencies.
• Optical diffraction MTF — for a circular aperture, the MTF rolls off as a function of f/(lambda x f-number). The cutoff frequency is 1/(lambda x F/#).
• Combined system MTF — the product of all components determines the effective resolution.

Nyquist and Aliasing

The pixel sampling frequency is f_Nyquist = 1/(2 x pitch). Spatial frequencies above Nyquist are aliased, producing moire artifacts. The simulator shows how pitch, wavelength, and f-number interact to determine whether the system is diffraction-limited or pixel-limited.

TIP

A well-designed system balances optical MTF cutoff near the pixel Nyquist frequency — oversampling wastes pixels, while undersampling creates aliasing.