{"uid":"cap_VCJ_5m0uqo-Jhqhi1mY9G","slug":"photography-calculators-exposure-value-ev-calculator-47ef0f48","name":"Photography Calculators: Exposure Value (EV) Calculator","description":"Exposure value (EV) from aperture, shutter speed and ISO, the light level it suits, and equivalent aperture and shutter pairs.","url":"https://photo-calc.x402tookit.com/exposure-value?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET"],"type":"string"},"queryParams":{"type":"object","required":["aperture","shutter"],"properties":{"iso":{"type":"number","description":"ISO (default 100)"},"shutter":{"type":"string","description":"Shutter time such as 1/125 or 0.5"},"aperture":{"type":"number","description":"f-number, e.g. 8"}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object","properties":{"iso":{"type":["null","number"]},"asOf":{"type":["null","string"]},"ev100":{"type":["null","number"]},"source":{"type":["null","string"]},"evAtIso":{"type":["null","number"]},"reasons":{"type":["array","null"],"items":{"type":"string"}},"summary":{"type":["null","string"]},"verdict":{"type":["null","string"]},"aperture":{"type":["null","number"]},"degraded":{"type":["boolean","null"]},"shutterS":{"type":["null","number"]},"disclaimer":{"type":["null","string"]},"notChecked":{"type":["array","null"],"items":{"type":"string"}},"suitsLight":{"type":["null","string"]},"equivalentPairsAtSameIso":{"type":["array","null"],"items":{"type":"object","properties":{"aperture":{"type":["null","number"]},"exactShutterS":{"type":["null","number"]},"nearestStandardShutter":{"type":["null","string"]}}}}}}}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.02","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.02/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.02","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.02","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_baDcXx1CCmunKnrM7D38k","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.02","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Calculates exposure value (EV) from aperture, shutter speed, and ISO, identifies the light level it suits, and returns equivalent aperture/shutter speed pairs.","exampleAgentPrompt":"What's the exposure value for f/8, 1/125s at ISO 400, what kind of light does that suit, and can you list me some equivalent aperture and shutter combinations at the same ISO?","exampleUseCases":[{"title":"Verify exposure for bright overcast scene","prompt":"I'm shooting outside in light overcast today with my camera set to f/5.6 and 1/250s at ISO 100 — can you calculate the EV and tell me if that suits the lighting conditions?"},{"title":"Find equivalent exposure pairs for creative choice","prompt":"I want to keep the same exposure as f/8 at 1/500s with ISO 200, but I need to know what other aperture and shutter speed combinations give me identical exposure so I can choose based on depth of field or motion blur."},{"title":"Cross-check EV for indoor event photography","prompt":"I'm shooting an indoor event at f/2.8, 1/60s and ISO 1600 — what's the EV, and does that match typical indoor artificial light levels?"}],"resultDescription":"Returns the EV at ISO 100 (ev100), EV adjusted for the given ISO (evAtIso), a human-readable description of what lighting conditions the EV suits (suitsLight), a list of equivalent aperture and shutter speed pairs at the same ISO (each with exact and nearest-standard shutter), plus a summary string, and optional warnings or degraded-mode flags.","failureModes":["Missing required aperture or shutter parameters returns an error","Invalid shutter format (not parseable as fraction or decimal) causes a parse failure","Extreme or out-of-range aperture/shutter values may produce degraded results with warnings","ISO of 0 or negative values may produce undefined or error responses"],"whenToPreferThis":"Use this endpoint when you need to compute or verify photographic exposure value from known camera settings, understand what lighting a given exposure is calibrated for, or explore equivalent exposure combinations. Prefer it over manual EV tables when ISO flexibility or a structured list of equivalent pairs is needed at low cost.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-29T13:12:38.302Z","isFirstParty":false,"canonicalSlug":"photography-calculators-exposure-value-ev-calculator-47ef0f48"}