{"uid":"cap_UT4sp8qTvElA4---CUT3M","slug":"nd-filter-calculator-11648e1f","name":"ND Filter Calculator","description":"ND filter maths: convert between ND factor, stops and optical density, and get the new shutter time with the filter on.","url":"https://photo-calc.x402tookit.com/nd-filter?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":["shutter"],"properties":{"stops":{"type":"number","description":"Filter strength in stops (give exactly one of stops, factor or density)"},"factor":{"type":"number","description":"ND factor such as 64 for ND64"},"density":{"type":"number","description":"Optical density such as 1.8 for ND1.8"},"shutter":{"type":"string","description":"Metered shutter without the filter, e.g. 1/60"}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object","properties":{"asOf":{"type":["null","string"]},"stops":{"type":["null","number"]},"source":{"type":["null","string"]},"reasons":{"type":["array","null"],"items":{"type":"string"}},"summary":{"type":["null","string"]},"verdict":{"type":["null","string"]},"degraded":{"type":["boolean","null"]},"duration":{"type":["null","string"]},"ndFactor":{"type":["null","number"]},"disclaimer":{"type":["null","string"]},"newShutter":{"type":["null","string"]},"notChecked":{"type":["array","null"],"items":{"type":"string"}},"newShutterS":{"type":["null","number"]},"commonFilters":{"type":["null","object"],"properties":{"ND2":{"type":["null","string"]},"ND4":{"type":["null","string"]},"ND8":{"type":["null","string"]},"ND64":{"type":["null","string"]},"ND1000":{"type":["null","string"]},"ND64000":{"type":["null","string"]}}},"opticalDensity":{"type":["null","number"]},"originalShutterS":{"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_VKxrT45XBf8L7fmsx0Vv1","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":"Converts between ND factor, stops, and optical density, then computes the new shutter speed when an ND filter is applied.","exampleAgentPrompt":"My metered shutter speed is 1/60 and I'm putting on an ND64 filter — what shutter speed should I use now, and can you also tell me the optical density and stops for that filter?","exampleUseCases":[{"title":"Long exposure waterfall shot","prompt":"I want to shoot a waterfall with a silky blur effect. My metered shutter without any filter is 1/125 and I'm using an ND1000 filter — what shutter speed should I dial in?"},{"title":"Converting ND stops to factor","prompt":"I keep hearing about 10-stop ND filters but my filter is labeled ND1024 — can you tell me how many stops that is and what the optical density is?"},{"title":"Choosing filter for target shutter speed","prompt":"I want to shoot at 1/8000 metered speed but actually need a 2-second exposure for a creative blur. What ND factor and how many stops of filtration do I need? My base shutter is 1/8000."}],"resultDescription":"Returns the computed new shutter speed (as a human-readable string and raw seconds), the ND factor, number of stops, optical density, original shutter in seconds, and a handy comparison table showing what shutter speed you'd get with common ND filters (ND2, ND4, ND8, ND64, ND1000, ND64000) at your metered speed.","failureModes":["Missing shutter parameter returns an error since it is required","Providing more than one of stops/factor/density may cause ambiguity or an error","Invalid shutter format (e.g. not a fraction or decimal) may fail to parse","Providing zero or negative values for stops, factor, or density is likely invalid","Network or payment failure returns a 402 or connection error"],"whenToPreferThis":"Use this endpoint when you need precise ND filter exposure math — converting between ND factor, stops, and optical density, or computing the correct shutter speed after adding a neutral density filter. It is the right choice for photography workflow agents, camera assistant apps, or long-exposure planning tools. Prefer it over generic calculators when you specifically need the photography-domain output format including human-readable shutter strings and a common-filter comparison table.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-30T00:34:23.647Z","isFirstParty":false,"canonicalSlug":"nd-filter-calculator-11648e1f"}