Super 8mm Light Meter ISO Calibration Tool

A professional-grade, browser-based utility designed for cinematographers and film enthusiasts to verify and calibrate manual light meters against reference standards.

Core Features

• ISO Reference Calculator: Convert light values (EV) into f-stop/shutter speed combinations specific to common Super 8 film speeds (e.g., ISO 50, 100, 200, 500).
• Variance Analysis: Input actual meter readings vs. theoretical light values to automatically calculate the percentage of deviation.
• Reciprocity Failure Guide: A quick-reference lookup table for reciprocity characteristics of common film stocks to prevent under-exposure during long exposures.
• Light Source Generator: A full-screen "White/Grey Card" mode that turns your screen into a consistent light source for testing (note: ensure screen brightness is at maximum).

UI Layout

• Header: Clean, centered title with a descriptive subtitle. A subtle navigation bar for switching between 'Calibrate', 'Reference', and 'Calculators'.
• Main Dashboard:
  • Left Column: Light meter input fields (ISO, Metered f-stop, Metered Shutter Speed).
  • Right Column: Real-time results showing the "Calculated Error" and "Correction Factor".
• Reference Sidebar: A collapsible panel showing standard exposure values for daylight, tungsten, and low-light scenarios.
• Feedback Section: A prominent 'status indicator' (e.g., Green for 'Accurate', Yellow for 'Requires Minor Adjustment', Red for 'Needs Professional Service').

Technical Specifications

• Architecture: Single-file HTML5/Vanilla JS. No external build steps.
• State Management: Purely in-memory via JavaScript objects. Strict prohibition of localStorage or sessionStorage per security requirements.
• Responsiveness: Fluid grid layout using CSS Flexbox/Grid. The app should perform perfectly on a mobile phone held near the light meter, or on a desktop.
• Visuals:
  • Palette: Clean, professional light mode. Use #F8FAFC (Slate 50) as the background, #FFFFFF for content cards, and #2563EB (Blue 600) for primary interactive buttons.
  • Animations: Subtle transition: all 0.3s ease; on all input focus states and button hover events to ensure a responsive, tactile feel.
  • Typography: Sans-serif, geometric fonts (e.g., Inter or System UI fonts) for high readability.

Developer Directives

• Security: Do not use localStorage, sessionStorage, or cookies. The tool must function without persistent state.
• Interactivity: Replace standard browser alert() or confirm() with custom-built modal overlays if user feedback is required.
• External Assets: Use CDNs for Tailwind CSS (via CDN) and Lucide Icons. Ensure all links have target="_blank" rel="noopener noreferrer".
• Aesthetic: Maintain a "SaaS" aesthetic. Use high-quality shadows (e.g., shadow-sm on inputs, shadow-md on cards) and rounded corners (rounded-lg) throughout.