Modulation Transfer Function

Section Overview:

The modulation transfer function (MTF) is a measurement of the microscope's ability to transfer contrast from the specimen to the intermediate image plane at a specific resolution. Computation of the modulation transfer function is a mechanism that is often utilized by optical manufacturers to incorporate resolution and contrast data into a single specification. Measurements of the relative modulation is useful for characterizing not only traditional optical systems, but also photonic systems such as analog and digital video cameras, image intensifiers, and film scanners.

Review Articles

Basic Concepts

Modulation of the output signal, the intensity of light waves forming an image of the specimen, corresponds to the formation of image contrast in microscopy. Therefore, a measurement of the MTF for a particular optical microscope can be obtained from the contrast generated by periodic lines or spacing present in a specimen that result from sinusoidal intensities in the image that vary as a function of spatial frequency. Topics covered in this section also include the optical transfer function, phase transfer function, and the contrast transfer function, all of which play a crucial role in resolution and contrast.

Interactive Tutorials

Selected Literature References

Selected Literature References

The reference materials listed in this section are an excellent source of information on the modulation transfer function, contrast transfer function, and optical transfer function as applied to microscopes and other optical systems, video systems, and photographic film.

Contributing Authors

Mortimer Abramowitz - Olympus America, Inc., Two Corporate Center Drive., Melville, New York, 11747.

Kenneth R. Spring - Scientific Consultant, Lusby, Maryland, 20657.

John C. Long, Matthew Parry-Hill, and Michael W. Davidson - National High Magnetic Field Laboratory, 1800 East Paul Dirac Dr., The Florida State University, Tallahassee, Florida, 32310.