Source: https://guthlabs.ai/docs/instruments/telescope-magnification/implementation/

instrument implementation / implementation-contract

# Telescope Magnification implementation

A source-bound implementation contract for Telescope Magnification; deployment and executable qualification remain separate.

Status: **VERIFIED_CLEAN**Lifecycle: **implementation-contract**

## Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

**Record owner**: Guth Instruments

**Lifecycle**: verified-clean

**Evidence ID**: t3-005

**Effect**: Computation or source lookup only

## Input and validation requirements

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.

## Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

## Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

````
{
  "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."
}
````

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/telescope-magnification/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/telescope-magnification/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/telescope-magnification/qualification/>)

## Sources and evidence

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

- `VERIFIED_LEDGER.json`

- `evidence-tranche3/tranche3-results.json`