Telescope Field of View

Inspectable records

Ledger state

The current ledger marks this instrument verified clean within the source-bound verification corpus.

Area

Earth & Space (astronomy, orbital mechanics, meteorology, geology, geodesy, oceanography)

Tranche

tranche-3

Evidence ID

t3-017

Ledger rows

1

No ledger note is attached.

Review findings

The stated honest label appropriately identifies this as an approximation, but the user-facing name or output should say approximate true field of view unless field-stop and distortion corrections are implemented.

Formula and scope findings

• AFOV/M is the standard nominal approximation, not an exact true-field formula; actual field of view depends on the eyepiece field stop and optical distortion.
• The phrase "magnification (or focal lengths)" is ambiguous because it does not explicitly identify telescope and eyepiece focal lengths or state that M = telescope focal length / eyepiece focal length.

Unit assumptions

• AFOV is expressed in degrees.
• Magnification M is dimensionless and must be positive.
• If focal lengths are supplied, telescope and eyepiece focal lengths must use the same units; M = F_telescope / F_eyepiece.
• Convert degrees to arcminutes with 1 degree = 60 arcminutes.

Boundary hardening

Recorded hazards

• Division by zero occurs when magnification is zero.
• Zero or negative magnification is physically invalid and should be rejected; focal lengths must be positive.
• The approximation can be inaccurate for eyepieces with significant angular distortion or when the field stop limits the view.
• Very large AFOV-to-magnification results may exceed the physically usable field of the telescope or eyepiece.

Errata and corrections

No applied erratum is attached to this unique-name record.

Inspectable example

4 review vectors are recorded. One source-bound sample is shown below.

{
  "inputs": {
    "eyepiece_AFOV_deg": 50,
    "magnification": 100
  },
  "expected_outputs": {
    "true_FOV_deg": 0.5,
    "true_FOV_arcmin": 30
  },
  "working": "TFOV = AFOV / M = 50 / 100 = 0.5 degrees. Arcminutes = 0.5 × 60 = 30 arcminutes."
}

Related workflows

Sources and evidence

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

• VERIFIED_LEDGER.json · VERIFIED_CLEAN
• evidence-tranche3/tranche3-results.json