Telescope Magnification

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

t3-005

Ledger rows

1

No ledger note is attached.

Review findings

Core focal-length magnification arithmetic is valid after unit normalization, but the instrument cannot honestly provide its declared exit-pupil output without aperture and its formula. Clarify signed versus unsigned magnification, add aperture as an input, define exit pupil = aperture/M, and revise the label to state that an exit pupil larger than the observer's eye pupil may be clipped rather than categorically wasted.

Formula and scope findings

• M = f_telescope/f_eyepiece is the standard magnitude formula for an astronomical telescope when both focal lengths use the same units and M denotes unsigned magnification. The signed angular magnification for a conventional Keplerian telescope is negative because the image is inverted.
• The spec lists exit pupil as an output but provides neither an exit-pupil formula nor the telescope aperture input required to calculate it. The standard formula is exit pupil = aperture/M = aperture × f_eyepiece/f_telescope.
• The claimed computation is ambiguous about whether magnification should be reported as a positive magnitude or as signed angular magnification.

Unit assumptions

• Telescope and eyepiece focal lengths must be expressed in the same length units before division; mixed units require conversion.
• Focal lengths should be positive, nonzero physical focal lengths. An eyepiece focal length of zero causes division by zero.
• Exit pupil is a diameter and requires telescope aperture, expressed in a length unit compatible with the focal lengths.
• The reported magnification values below use unsigned magnification; signed Keplerian angular magnification would have the same magnitude with a negative sign.

Boundary hardening

BREAK_CLAIMED · SELF_FLAGGED

The division-by-zero input produces an undefined magnification that must be rejected. Independently, the requested exit-pupil output cannot be computed for any vector because telescope aperture is absent from the inputs and formulas. No genuine formula-branch regime is defined.

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": {
    "telescope_focal_length": 1200,
    "telescope_focal_length_unit": "mm",
    "eyepiece_focal_length": 25,
    "eyepiece_focal_length_unit": "mm"
  },
  "expected_outputs": {
    "magnification": 48,
    "exit_pupil": null
  },
  "working": "M = f_telescope / f_eyepiece = 1200 mm / 25 mm = 48. Exit pupil cannot be computed because aperture is not supplied."
}

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
• BOUNDARY_HAZARD_CATALOG.json