{"uid":"cap_x1FwKd1lLzmGKRuBu4rzq","slug":"photography-calculators-sunny-16-rule-42e74f33","name":"Photography Calculators – Sunny-16 Rule","description":"The sunny-16 rule: starting aperture and shutter speed for sun, cloud or shade at your ISO, with the exposure value it implies.","url":"https://photo-calc.x402tookit.com/sunny-16?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":["weather"],"properties":{"iso":{"type":"number","description":"ISO or film speed (default 100)"},"weather":{"type":"string","description":"snow-sand, sunny, slight-overcast, overcast, heavy-overcast or open-shade"}}}},"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"]},"reasons":{"type":["array","null"],"items":{"type":"string"}},"shutter":{"type":["null","string"]},"summary":{"type":["null","string"]},"verdict":{"type":["null","string"]},"weather":{"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"}},"description":{"type":["null","string"]},"equivalents":{"type":["array","null"],"items":{"type":"object","properties":{"shutter":{"type":["null","string"]},"aperture":{"type":["null","number"]}}}}}}}}}},"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_dv2bp42_FsqaRYrbgHmBC","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":"Returns starting aperture, shutter speed, and exposure value for a given weather condition and ISO using the Sunny-16 rule, plus equivalent exposure combinations.","exampleAgentPrompt":"Using the sunny-16 rule, what aperture and shutter speed should I start with for a slightly overcast day shooting at ISO 400?","exampleUseCases":[{"title":"Film shooter dialing in exposure","prompt":"I'm shooting a roll of ISO 200 film in open shade today — what aperture and shutter speed does the sunny-16 rule recommend, and what equivalent combinations can I use?"},{"title":"Bright beach or snow shoot","prompt":"I'm about to shoot on the beach in full sun with my camera set to ISO 100. Give me the sunny-16 starting exposure and the EV it corresponds to."},{"title":"Overcast street photography setup","prompt":"It's heavily overcast outside and I'm shooting at ISO 800 — what does sunny-16 say my starting shutter speed and aperture should be?"}],"resultDescription":"Returns the recommended aperture (f-number), shutter speed (as a fraction string and decimal seconds), ISO used, EV100 value, a plain-English summary of the lighting level, a list of equivalent exposure combinations (different aperture/shutter pairs at the same EV), weather condition echoed back, and a disclaimer about the rule being a starting point.","failureModes":["Missing required 'weather' query parameter returns an error","Invalid weather enum value (e.g. 'foggy') causes a validation error","Very high or unusual ISO values may yield unexpected results","Network timeout or upstream service unavailability"],"whenToPreferThis":"Choose this endpoint when you need a quick, rule-based starting exposure for outdoor natural-light photography without a light meter, especially for film photographers or anyone unfamiliar with metering. It is ideal for coaching users on the sunny-16 rule rather than computing a precise light measurement.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-29T13:11:14.054Z","isFirstParty":false,"canonicalSlug":"photography-calculators-sunny-16-rule-42e74f33"}