Diffraction Limit / Optimal Aperture Calculator mechanism

Model scope

The honest-label warning about physical-optics approximation and lens quality is appropriate but incomplete. The product must disclose the explicit diffraction criterion and resolve the contradiction between N=pixelPitch/(1.22λ) and Airy diameter=2.44λN before claiming a standard diffraction-limit calculation.

• The stated formula N≈pixelPitch/(1.22*λ) is not consistent with the stated Airy-disk diameter formula when the criterion is that the Airy disk diameter equals one pixel. Substitution gives Airy diameter=2.44*λ*(pixelPitch/(1.22*λ))=2*pixelPitch. Under the one-pixel Airy-diameter criterion, the corresponding formula is N≈pixelPitch/(2.44*λ).
• The phrase "begins to visibly limit resolution" does not define a unique optical criterion. Depending on the chosen criterion, the relevant comparison may involve Airy-disk diameter, Airy radius, pixel pitch, or sensor Nyquist frequency; the criterion must be stated explicitly.
• The sensor megapixels-and-size input path does not specify whether size means active width and height, diagonal, or nominal format size, nor does it specify the aspect ratio and active-area assumptions needed to derive pixel pitch.

Units and conventions

• Pixel pitch and wavelength must use the same length unit; with λ=0.00055 mm, pixel pitch must be supplied in millimetres or converted to millimetres.
• The default λ≈0.00055 mm means 550 nm monochromatic green light; real scenes and sensors respond over a wavelength band.
• For megapixel-plus-size calculations, the sensor dimensions are assumed to be active imaging width and height in millimetres, pixels are square, and the stated megapixel count is the active pixel count.

Inspectable vector

One of 4 source-bound review vectors:

{
  "inputs": {
    "manual_pixel_pitch_mm": 0.004,
    "wavelength_mm": 0.00055
  },
  "expected_outputs": {
    "diffraction_limited_f_number": 5.961252,
    "airy_disk_diameter_mm": 0.008
  },
  "working": "1.22*λ = 1.22*0.00055 = 0.000671 mm. N = 0.004/0.000671 = 5.961252. Airy diameter = 2.44*0.00055*5.961252 = 0.008000 mm, equivalently 2*0.004 = 0.008000 mm."
}

Failure boundary

BREAK_CLAIMED · SELF_FLAGGED

The specification does not state validation behavior for zero megapixels, zero or negative pixel pitch, or other nonphysical inputs. Zero megapixels creates a division-by-zero during derived pixel-pitch calculation, while negative pixel pitch produces sign-dependent and physically invalid outputs unless explicitly rejected or converted to an absolute magnitude.

Other records

Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

• VERIFIED_LEDGER.json
• evidence-tranche5/tranche5-results.json
• BOUNDARY_HAZARD_CATALOG.json