ND filter maths
ND filter maths: convert between ND factor, stops and optical density, and get the new shutter time with the filter on.
Answeringour last check, 2026-10-21
1 of 1checks answered this week
783 msmedian answer time
$0.02listed price per call
$0.02price it asked us
Paid test badge: not yet. The checks above are free: we call the tool without paying and read the payment request it sends back. The Verified badge needs paid calls whose answers match the promised output, and nobody can buy a badge.
Endpoint
GET https://photo-calc.x402tookit.com/nd-filter
| Category | Image and media |
|---|---|
| Provider host | photo-calc.x402tookit.com |
| Networks | eip155:137, eip155:42161, eip155:8453, solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp |
| Payment schemes | exact |
| Self-reported calls, 30 days | 1 from 1 payers (the provider's figure, not ours) |
Our checks, last 30 days
| Day | Result | HTTP | Asked | Time |
|---|---|---|---|---|
| 2026-10-21 | valid payment request | 402 | $0.02 | 783 ms |
Example input (from the provider)
{
"method": "GET",
"queryParams": {
"shutter": "1/60",
"stops": 10
},
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"method": {
"enum": [
"GET"
],
"type": "string"
},
"queryParams": {
"properties": {
"density": {
"description": "Optical density such as 1.8 for ND1.8",
"type": "number"
},
"factor": {
"description": "ND factor such as 64 for ND64",
"type": "number"
},
"shutter": {
"description": "Metered shutter without the filter, e.g. 1/60",
"type": "string"
},
"stops": {
"description": "Filter strength in stops (give exactly one of stops, factor or density)",
"type": "number"
}
},
"required": [
"shutter"
],
"type": "object"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"properties": {
"asOf": {
"type": [
"null",
"string"
]
},
"commonFilters": {
"properties": {
"ND1000": {
"type": [
"null",
"string"
]
},
"ND2": {
"type": [
"null",
"string"
]
},
"ND4": {
"type": [
"null",
"string"
]
},
"ND64": {
"type": [
"null",
"string"
]
},
"ND64000": {
"type": [
"null",
"string"
]
},
"ND8": {
"type": [
"null",
"string"
]
}
},
"type": [
"null",
"object"
]
},
"degraded": {
"type": [
"boolean",
"null"
]
},
"disclaimer": {
"type": [
"null",
"string"
]
},
"duration": {
"type": [
"null",
"string"
]
},
"ndFactor": {
"type": [
"null",
"number"
]
},
"newShutter": {
"type": [
"null",
"string"
]
},
"newShutterS": {
"type": [
"null",
"number"
]
},
"notChecked": {
"items": {
"type": "string"
},
"type": [
"array",
"null"
]
},
"opticalDensity": {
"type": [
"null",
"number"
]
},
"originalShutterS": {
"type": [
"null",
"number"
]
},
"reasons": {
"items": {
"type": "string"
},
"type": [
"array",
"null"
]
},
"source": {
"type": [
"null",
"string"
]
},
"stops": {
"type": [
"null",
"number"
]
},
"summary": {
"type": [
"null",
"string"
]
},
"verdict": {
"type": [
"null",
"string"
]
}
},
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}