{
  "slug": "exposure-value",
  "title": "Exposure Value (EV) Calculator",
  "heading": "Exposure Value & Equivalent Exposure Calculator",
  "category": "other",
  "url": "https://www.revenuelab.fyi/toolbox/exposure-value",
  "summary": "EV from aperture, shutter, and ISO — plus equivalent settings.",
  "description": "Exposure value collapses aperture, shutter speed, and ISO into a single number, which makes it trivial to find equivalent settings or to see how many stops you are away from a target exposure.",
  "formula": "EV100 = log2(N² ÷ t) − log2(ISO ÷ 100).",
  "dateModified": "2026-09-30",
  "run_url": "https://www.revenuelab.fyi/api/public/calc?tool=exposure-value",
  "inputs": [
    {
      "id": "aperture",
      "label": "Aperture (f-number)",
      "kind": "number",
      "hint": null,
      "default": 5.6,
      "unit": null,
      "min": 0.7,
      "max": null
    },
    {
      "id": "shutter",
      "label": "Shutter speed denominator (1/x sec)",
      "kind": "number",
      "hint": null,
      "default": 125,
      "unit": null,
      "min": 0.001,
      "max": null
    },
    {
      "id": "iso",
      "label": "ISO",
      "kind": "number",
      "hint": null,
      "default": 400,
      "unit": null,
      "min": 25,
      "max": null
    },
    {
      "id": "newAperture",
      "label": "New aperture to match",
      "kind": "number",
      "hint": null,
      "default": 2.8,
      "unit": null,
      "min": 0.7,
      "max": null
    },
    {
      "id": "ndStops",
      "label": "ND filter strength",
      "kind": "number",
      "hint": null,
      "default": 0,
      "unit": "stops",
      "min": 0,
      "max": 20
    }
  ],
  "outputs": [
    {
      "id": "ev100",
      "label": "EV at ISO 100",
      "format": "decimal",
      "hint": null,
      "primary": true
    },
    {
      "id": "ev",
      "label": "EV at your ISO",
      "format": "decimal",
      "hint": null,
      "primary": false
    },
    {
      "id": "newShutter",
      "label": "Shutter for the new aperture",
      "format": "raw",
      "hint": null,
      "primary": false
    },
    {
      "id": "ndShutter",
      "label": "Shutter with the ND filter",
      "format": "raw",
      "hint": null,
      "primary": false
    },
    {
      "id": "lux",
      "label": "Approximate scene illuminance (lux)",
      "format": "number",
      "hint": null,
      "primary": false
    }
  ],
  "worked_example": {
    "inputs": [
      "Aperture (f-number): 5.6",
      "Shutter speed denominator (1/x sec): 125",
      "ISO: 400",
      "New aperture to match: 2.8",
      "ND filter strength: 0 stops"
    ],
    "outputs": [
      "EV at ISO 100: 9.94",
      "EV at your ISO: 11.94",
      "Shutter for the new aperture: 1/500 s",
      "Shutter with the ND filter: 1/125 s",
      "Approximate scene illuminance (lux): 2,450"
    ]
  },
  "how_to": {
    "title": "How to use this",
    "steps": [
      "Enter aperture (f-number).",
      "Enter shutter speed denominator (1/x sec).",
      "Enter iso.",
      "Enter new aperture to match.",
      "Enter nd filter strength (stops).",
      "Read your ev at iso 100 on the right — it updates as you type.",
      "Hit Share to keep the scenario or send it to someone."
    ]
  },
  "scenarios": [
    {
      "name": "Conservative",
      "description": "Lower-end numbers — what if things land soft?",
      "values": {
        "aperture": 3.36,
        "shutter": 75,
        "iso": 250,
        "newAperture": 1.68,
        "ndStops": 0
      }
    },
    {
      "name": "Typical",
      "description": "Defaults — the most common real-world setup.",
      "values": {
        "aperture": 5.6,
        "shutter": 125,
        "iso": 400,
        "newAperture": 2.8,
        "ndStops": 0
      }
    },
    {
      "name": "Ambitious",
      "description": "Higher-end numbers — what if things really pop?",
      "values": {
        "aperture": 8.959999999999999,
        "shutter": 200,
        "iso": 650,
        "newAperture": 4.4799999999999995,
        "ndStops": 0
      }
    }
  ],
  "limitations": [
    "Estimates assume standard, average conditions — local rules, pricing, and materials vary.",
    "Results are rounded for readability; add a buffer before ordering, booking, or committing.",
    "Double-check anything with a real cost attached against a local quote."
  ],
  "faq": [
    {
      "q": "What is Sunny 16?",
      "a": "Bright direct sun is roughly EV 15 at ISO 100 — f/16 at 1/100 s. Every stop of shade or overcast drops it by one to four EV."
    },
    {
      "q": "How do I use this for long exposures?",
      "a": "Meter normally, enter the ND strength, and read the ND shutter output. A 10-stop filter turns 1/125 s into about eight seconds."
    }
  ],
  "related": [
    "https://www.revenuelab.fyi/toolbox/depth-of-field",
    "https://www.revenuelab.fyi/toolbox/field-of-view"
  ],
  "license": "CC-BY-4.0",
  "citation": "RevenueLab — Exposure Value (EV) Calculator (https://www.revenuelab.fyi/toolbox/exposure-value)"
}