Exposure Bracketing / HDR Stops Planner implementation

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

t4-252

Effect

Computation or source lookup only

Input and validation requirements

The extreme valid-number input produces a non-finite Infinity output, and the specification does not define validation or rejection behavior. The unspecified frame-index and shutter-direction conventions can also produce reversed or differently centered bracket lists.

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": {
    "base_seconds": 0.008,
    "number_of_frames": 3,
    "stop_step": 1,
    "n_indices": [
      -1,
      0,
      1
    ]
  },
  "expected_outputs": {
    "shutter_seconds": [
      0.004,
      0.008,
      0.016
    ]
  },
  "working": "For n=-1: 0.008*2^(-1*1)=0.008*(1/2)=0.004 s. For n=0: 0.008*2^(0*1)=0.008*1=0.008 s. For n=1: 0.008*2^(1*1)=0.008*2=0.016 s."
}

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-tranche4/tranche4-results.json