field-angle card · index card with a stamped header

Match Rectilinear Horizontal Framing with Active Sensor Widths

Two camera modes can use different active sensor widths even when their lens labels look close. Match horizontal angle explicitly before describing a multi-camera framing plan as equivalent.

1 · Camera setup | active sensor width (mm) | actual focal length (mm)

FIRST-LOAD

HYPOTHESIS / PROTOTYPE — checkout unavailable. Calculation is local. A draft is saved automatically in this browser profile when storage is available; Reset to sample clears it. Optional Pro history stores only five summaries and has its own deletion control. State links encode your inputs and can remain in browser history, clipboard or recipients’ records; share only non-sensitive rows. Optional external AI formatting leaves this device. The required site analytics beacon reports page activity; shared URLs contain encoded inputs. Do not treat an encoded URL as private. The calculator has no input-collection endpoint.

Data note: The field-angle card processes Camera setup | active sensor width (mm) | actual focal length (mm) locally. Starter/sample selection and Run compute in this tab; no input is sent by the calculator. A local draft may be saved; explicit state-link sharing or optional external AI formatting can disclose inputs. Use non-sensitive labels.

Perspective: Before: lens labels were assumed to mean matching coverage. After: active width, current angle and a reference-matching focal length are separate production quantities.

2 · Read the field-angle card

Ideal rectilinear framing geometry only, not an equipment-performance guarantee. Confirm active recording dimensions and test actual framing; ask a qualified camera technician about crops, distortion, breathing or anamorphic modes before a consequential shoot.

Paid layer: field-angle card filing layer

one-time step · the free reading above stays complete

hidden patterns detected after your first run

Free tier

one complete unwatermarked field-angle card run in the app
three labeled samples and unlimited article-demo calculations
complete result text and a user-triggered input-state link

What $4 one-time adds

unlimited subsequent field-angle card app calculations after a local convenience signal
print the field-angle card with visible assumptions and its safety boundary
CSV of the displayed degrees absolute mismatch and row workings; conditional estimate uses your manual-retyping minutes
five local reading summaries (headline/count/time), not saved full inputs or cross-device backups

HYPOTHESIS / PROTOTYPE: $4 is a proposed one-time price for filing the field-angle card, not a current sales offer. No measured time saving or buyer demand is claimed. The optional manual-retyping baseline above estimates one export’s retyping budget only; it does not change the calculation or guarantee savings.

Local history (this device)

No saved runs yet — your first run files here.

Filing prototype — checkout unavailable

Checkout is unavailable. Browser-local, profile-scoped convenience gating is best-effort, not server-verified access. A URL or browser flag is not proof of payment. Clearing browser data removes local state; no account or cross-device recovery is provided.

Optional filing controls are a local prototype.

Checkout is unavailable. The reading above is complete; print, CSV and five local summaries are optional enhancements, not hidden answers.

Before using the field-angle card

Use the physical width of the sensor region active in the selected recording mode, not a diagonal sensor size or a nominal crop factor unless converted and verified separately. The formula assumes a rectilinear ideal lens focused under a suitable geometric model. Fisheye mapping, distortion correction, anamorphic desqueeze, focus breathing and digital stabilization crops can invalidate it. Sensor width and focal length must be positive millimeter quantities. The chosen reference angle lies strictly between zero and 180 degrees. Rows are alternative camera setups, and the summary is the largest absolute angular mismatch, not a sum of angles or a quality rating. A matching focal length is a mathematical target, not proof that an available lens can provide the framing.

Boundary and sources

Method: Current angle is 2×atan(active width/(2×focal length)), converted from radians to degrees. A focal length matching reference angle A is width/(2×tan(A/2)). The card retains the signed angle difference while the summary takes its largest absolute magnitude. Small floating-point residuals are displayed with six-decimal rounding, not treated as equipment measurement precision.
All sample records, dates, quantities and labels are invented. No outside policy, contract, rate, clock offset, measurement or accessibility standard is represented as verified.
Google’s official pricing documentation, fetched 2026-10-01, says AI Studio is free in available regions. Optional formatting may require a Google account; manual local entry requires none. Limits can change and free-tier content may be used to improve products. Do not send private records.

Mechanism: competence-autonomy-loop

Optional AI formatting, never the calculation

Manual entry completes this field-angle card for free without signup. If available to you, the free AI Studio interface linked in the sources may format fictional or non-sensitive notes; external access may require an account. No API key or AI call is built into this tool. Free-tier content may be used to improve products. Review each cell and transcribe it to the labeled row schema; do not paste the JSON object into the row box.

Format only these fictional or non-sensitive notes for a field-angle card. Return strict JSON shaped as {"rows": [{"label": "string", "cells": ["string", "string"]}], "setting": "string"}. The columns are Camera setup | active sensor width (mm) | actual focal length (mm); the setting is Chosen reference horizontal field angle (degrees). Keep all supplied strings and quantities exactly; do not calculate, infer missing entries, invent dates or add advice. If any required value is missing, return an empty rows array and ask me for it separately. I will verify every cell against my source and manually transcribe rows using vertical bars before running the local calculator.

An AI response is not executed, fetched or trusted as a result. Missing values remain questions; the strict local parser checks the rows you actually enter.