Calculation of contrast for computer simulated resolution chart image

Abstract The work is devoted to the analysis of the resolution chart image created with the Image Simulation mode of ZEMAX software. The changes in image quality are simulated using the model of Helios-44M-4 photographic objective lens. The research is conducted for monochromatic light conditions and computer simulated resolution test chart as an object for the lens with different chart positions. An axial beam and an off-axis beam that corresponds to the maximum object space field angle are analyzed. The calculation of contrast of the simulated resolution chart images is made modeling different spatial frequencies of the chart lines. The contrast is calculated in three ways. The first way uses the maximum and minimum values of the image illumination, and the second and third ways are based on the integral values of the illumination of black and white lines, calculated with the method of rectangles and the method of trapeziums, respectively. Having been calculated the values of contrast are compared with the theoretical values of the diffraction modulation transfer function obtained with ZEMAX.

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Calculation of ocular single-pass modulation transfer function and retinal image simulation from measurements of the polarized double-pass ocular point spread function

Journal of Biomedical Optics ◽

10.1117/1.1627777 ◽

2004 ◽

Vol 9 (1) ◽

pp. 154 ◽

Cited By ~ 4

Author(s):

Katsuhiko Kobayashi ◽

Masahiro Shibutani ◽

Gaku Takeuchi ◽

Kazuhiko Ohnuma ◽

Yoichi Miyake ◽

...

Keyword(s):

Transfer Function ◽

Point Spread Function ◽

Modulation Transfer Function ◽

Retinal Image ◽

Image Simulation ◽

Modulation Transfer ◽

Double Pass ◽

Single Pass ◽

Point Spread ◽

Spread Function

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Fully Automated Measurement of the Modulation Transfer Function of Charge-Coupled Devices above the Nyquist Frequency

Microscopy and Microanalysis ◽

10.1017/s1431927611012633 ◽

2012 ◽

Vol 18 (2) ◽

pp. 336-342 ◽

Cited By ~ 16

Author(s):

Wouter Van den Broek ◽

Sandra Van Aert ◽

Dirk Van Dyck

Keyword(s):

Transfer Function ◽

Modulation Transfer Function ◽

Practical Method ◽

Automated Measurement ◽

Image Simulation ◽

Nyquist Frequency ◽

Modulation Transfer ◽

Good Correspondence ◽

Charge Coupled Devices ◽

Simulation And Experiment

AbstractThe charge-coupled devices used in electron microscopy are coated with a scintillating crystal that gives rise to a severe modulation transfer function (MTF). Exact knowledge of the MTF is imperative for a good correspondence between image simulation and experiment. We present a practical method to measure the MTF above the Nyquist frequency from the beam blocker's shadow image. The image processing has been fully automated and the program is made public. The method is successfully tested on three cameras with various beam blocker shapes.

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45.5X Infinity Corrected Schwarzschild Microscope Objective Lens Design

International Journal on Measurement Technologies and Instrumentation Engineering ◽

10.4018/ijmtie.2018010102 ◽

2018 ◽

Vol 7 (1) ◽

pp. 17-37

Author(s):

Sami D. Alaruri

Keyword(s):

Sensitivity Analysis ◽

Transfer Function ◽

Modulation Transfer Function ◽

Numerical Aperture ◽

Objective Lens ◽

Lens Design ◽

Modulation Transfer ◽

Microscope Objective ◽

Spherical Mirrors ◽

Microscope Objective Lens

In this article, the design of a 45.5X (numerical aperture (NA) =0.5) infinity corrected, or infinite conjugate, Schwarzschild reflective microscope objective lens is discussed. Fast Fourier transform modulation transfer function (FFT MTF= 568.4 lines/mm at 50% contrast for the on-axis field-of-view), root-mean-square wavefront error (RMS WFE= 0.024 waves at 700 nm), point spread function (PSF, Strehl ratio= 0.972), encircled energy (0.88 µm spot radius at 80% fraction of enclosed energy), optical path difference (OPD=-0.644 waves) and Seidel coefficients calculated with Zemax® are provided to show that the design is diffraction-limited and aberration-free. Furthermore, formulas expressing the relationship between the parameters of the two spherical mirrors and the Schwarzschild objective lens focal length are given. In addition, tolerance and sensitivity analysis for the Schwarzschild objective lens, two spherical mirrors indicate that tilting the concave mirror (or secondary mirror) has a higher impact on the modulation transfer function values than tilts introduced by the convex mirror (or primary mirror). Finally, the performed tolerance and sensitivity analysis on the lens design suggests that decentering any of the mirrors by the same distance has the same effect on the modulation transfer function values.

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