Lens MTF Performance vs Object Contrast Threshold Calculator

Quick Answer

Calculate Lens MTF Performance vs Object Contrast Threshold Calculator

Result Interpretation

Lens MTF Performance vs Object Contrast Threshold Calculator computes Minimum Resolvable Contrast in dimensionless using the defined engineering formula and the input values provided.

Worked Example

Verified calculation

Given:

Lens F-number = 2.8
Dominant Wavelength = 5.25E-7
Sensor Noise Floor (RMS) = 2.9
Sensor Pixel Pitch = 3.45E-6
Peak Signal Level = 115
MTF Spatial Frequency = 45000
Human/Algorithm Contrast Sensitivity Factor = 1.8

Expected Result:

Minimum Resolvable Contrast = 380204.08163266

Engineering Interpretation:

Under the given input conditions, the calculated result is: Minimum Resolvable Contrast = 380204.08163266 dimensionless.

The actual numerical result is computed by the Runtime engine using the persisted tool definition. The values shown here come from automatically validated test cases.

Formula / Method

minimum resolvable contrast = sqrt(pow(2.0 * mtf spatial frequency * sensor pixel pitch / (dominant wavelength * lens f-number), 2.0) + pow(RMS / peak signal level, 2.0)) * human/algorithm contrast sensitivity factor

Formula family: formula_machinevision_lens_mtf_performance_vs_object_contrast_threshold_calculator

Variables

Symbol	Label	Role	Description
mtf_spatial_freq	MTF Spatial Frequency	INPUT	MTF Spatial Frequency
pixel_pitch	Sensor Pixel Pitch	INPUT	Sensor Pixel Pitch
wavelength	Dominant Wavelength	INPUT	Dominant Wavelength
f_number	Lens F-number	INPUT	Lens F-number
noise_floor	Sensor Noise Floor (RMS)	INPUT	Sensor Noise Floor (RMS)
signal_level	Peak Signal Level	INPUT	Peak Signal Level
contrast_sensitivity_factor	Human/Algorithm Contrast Sensitivity Factor	INPUT	Human/Algorithm Contrast Sensitivity Factor
minimum_resolvable_contrast	Minimum Resolvable Contrast	OUTPUT	Minimum Resolvable Contrast

Calculation Steps

Enter the mtf spatial frequency in cycles_per_meter.
Enter the sensor pixel pitch in meter.
Enter the dominant wavelength in meter.
Enter the lens f-number in dimensionless.
Enter the sensor noise floor (rms) in digital_number.
Enter the peak signal level in digital_number.
Enter the human/algorithm contrast sensitivity factor in dimensionless.
Step 1: Compute minimum resolvable contrast.
Read the minimum resolvable contrast (dimensionless) from the results.

Engineering Summary

Calculate Lens MTF Performance vs Object Contrast Threshold Calculator

Frequently Asked Questions

What does this calculator calculate?

The Lens MTF Performance vs Object Contrast Threshold Calculator estimates Minimum Resolvable Contrast based on the input parameters you provide

Why is mtf spatial frequency important in this calculation?

mtf spatial frequency is directly proportional to minimum resolvable contrast. When you enter mtf spatial frequency in cycles_per_meter, the calculator uses it in the engineering formula to compute the output

How should I interpret the result minimum resolvable contrast?

The calculator outputs minimum resolvable contrast in dimensionless. The result is computed directly from the input values using the defined engineering formula

What units should I use for the inputs?

Enter each value in the units shown next to the input field: MTF Spatial Frequency (cycles_per_meter), Sensor Pixel Pitch (meter), Dominant Wavelength (meter), Lens F-number (dimensionless), Sensor Noise Floor (RMS) (digital_number), Peak Signal Level (digital_number), Human/Algorithm Contrast Sensitivity Factor (dimensionless). Make sure all inputs use the specified units for consistent results

What assumptions does this calculator use?

This calculator uses automatically validated engineering formulas. Results are approximate and should be validated against site-specific conditions, applicable codes, and professional engineering judgment

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