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Thin Lens Imaging & Rayleigh Resolution Calculator

Optical imaging systems are constrained by both geometric focal mechanics and fundamental wave diffraction.

Lens effective focal length.

Distance from object to lens entrance plane (> f).

Clear entrance pupil aperture diameter.

Light wavelength (green peak ≈ 550 nm).

Calculated Result
55.56 mm

Image Distance (di)

Magnification (m)

-0.111x

Diffraction Limit (Airy Radius)

1.34 µm

Angular Resolution

5.54 arcsec

Lens Speed (f-number)

f/2.0

Calculation Breakdown

  1. Thin Lens Equation1/di = 1/f - 1/do = 1/50 - 1/500 → di = 55.56 mm
  2. Rayleigh Criterionr_airy = 1.22 · λ · (f/D) = 1.22 · 550nm · 2.0 = 1.34 µm

What Is the Thin Lens Imaging & Rayleigh Resolution Calculator?

Thin lens imaging determines image position and scale, while the Rayleigh criterion defines the diffraction-limited resolution of the lens.

How Does the Thin Lens Imaging & Rayleigh Resolution Calculator Work?

Combines the Gaussian lens equation with the Fraunhofer circular aperture diffraction Bessel function null.

Thin Lens Imaging & Rayleigh Resolution Calculator Formula & Variables

The core mathematical equation utilized by this calculator is expressed as:

rac{1}{f} = rac{1}{d_o} + rac{1}{d_i}, quad m = - rac{d_i}{d_o}, quad r_{ ext{Airy}} = 1.22 lambda left( rac{f}{D} ight)

Thin lens Gaussian formula combined with Rayleigh diffraction limit.

How to Use the Thin Lens Imaging & Rayleigh Resolution Calculator

  1. Input focal length, object distance, entrance aperture diameter, and light wavelength.

Step-by-Step Example Calculation

Camera 50mm Prime Lens at f/2.0

Input Values:

focalLengthMm:50
objectDistanceMm:500
lensApertureDiameterMm:25
wavelengthNm:550
Worked Steps: Forms image at d_i = 55.56 mm with magnification -0.111x and Airy disk radius 1.34 µm.

Understanding Your Result

Airy disk radius defines the smallest spot diameter resolvable by the optical sensor pixels.

Factors That Affect the Result

  • Stopping down a lens increases depth of field but increases the Airy disk size (diffraction softening).

When Should You Use This Calculator?

  • Telescope aperture sizing, microscope objective selection, machine vision camera sensor matching.

Assumptions & Limitations

  • Assumes paraxial approximation and aberration-free (diffraction-limited) optics.

Frequently Asked Questions

Calculation Accuracy & Reference Note

Rayleigh diffraction limit for circular apertures.

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