Modulation Transfer Function (MTF) testing

What is the Modulation Transfer Function of an optical system?

Modulation Transfer Function (MTF) is commonly used to qualify and evaluate the performance of imaging systems, such as lens assemblies. MTF is a useful tool for measuring and characterizing the resolution and contrast of a lens, which are key factors in determining its overall quality. The MTF curve of a lens assembly shows the degree to which the system can transfer contrast from the object to the image plane at different spatial frequencies. The MTF curve provides information about the lens' resolving power, or its ability to distinguish fine details in the image.

No imaging system is perfect, and so the MTF curve of a real system will drop off at higher spatial frequencies due to factors such as lens wavefront aberrations.

MTF curve from Phasics software

What is the Modulation Transfer Function of an optical system?

The Modulation Transfer Function (MTF) is a valuable tool for manufacturers to assess the imaging capabilities of lenses and ensure they meet the desired standards for resolution and contrast. By analyzing the MTF curve, engineers can gain insights into the limitations and performance characteristics of a lens assembly. 

The Modulation Transfer Function is crucial for optimizing the design of lenses and improving the manufacturing process. Engineers can use the MTF to refine designs, address aberrations or limitations, and enhance the overall quality of the captured images. Furthermore, the MTF curve allows for meaningful comparisons between different lens assemblies or imaging systems, enabling engineers to make informed decisions. By leveraging the insights provided by the MTF, manufacturers can ensure their lenses meet the desired performance standards, researchers can evaluate and advance imaging technologies, and photographers can select lenses that best suit their needs for capturing high-resolution and high-contrast images.

  Discover Phasics Modulation Transfer Function testing station

Kaleo MTF testing station

Benefits of Phasics Kaleo MTF measurement station


  • Fast and fully automated measurements and analysis
  • Quick set-up with no alignment
  • Easy data management with an intuitive software


  • On and off-axis MTF measurement at any frequency without target
  • More than MTF with access to all aberrations of the lenses
  • Highly accurate and reproducible measurements


  • Various samples, even with very high CRA
  • Acquisitions available at several wavelengths
  • Measurement available for wide fields and all azimuths



Kaleo MTF testing station

Kaleo MTF testing station

Kaleo MTF, the key to complex high CRA lenses: article on Photoniques Magazine

The key to complex high CRA lenses

Kaleo MTF testing station specifications sheet

Kaleo MTF specification sheet

Kaleo MTF testing station on and off-axis product demonstration first slide presentation

Kaleo MTF Product demonstration

Kaleo MTF testing station : EPIC New product Release video

Kaleo MTF New Product Release

Lens assembly testing

Lens & Assembly testing

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