← The evidence ledger
Evidence row 2201250
Observed , by sync.x402_bazaar/1.
- Kind
- listing
- About
- source_record x402_bazaar:https://photo-calc.x402tookit.com/nd-filter
- Recorded
- Previous row
- None: the first of its kind about this subject
- Body SHA-256
- fc29ac58637bb9684c4420cd13eb0a7ffb700c5bfc6fb374601df13637a0f023
- Leaf
- 0x31b9abb639037eb74f34c9f05b281b9fe2f6cd30a5403c1b4f8cf2a65dbf420a
What was observed
{
"endpoints": [
[
"x402",
"https://photo-calc.x402tookit.com/nd-filter"
]
],
"name": "Photography Calculators",
"owner_address": "0xb531320805c5bed1d46aeadcf4f008fdf172dbda",
"raw": {
"accepts": [
{
"amount": "20000",
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"extra": {
"name": "USD Coin",
"version": "2"
},
"maxTimeoutSeconds": 300,
"network": "eip155:8453",
"payTo": "0xb531320805C5BED1D46AEaDcF4F008FDF172DBDa",
"scheme": "exact"
},
{
"amount": "20000",
"asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
"extra": {
"feePayer": "D6ZhtNQ5nT9ZnTHUbqXZsTx5MH2rPFiBBggX4hY1WePM",
"transactionVersions": [
0
]
},
"maxTimeoutSeconds": 300,
"network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
"payTo": "DUPiupXtuox38dcGoXUKer5mAydCzmaHjrbQ66qeEm8s",
"scheme": "exact"
},
{
"amount": "20000",
"asset": "0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359",
"extra": {
"name": "USD Coin",
"version": "2"
},
"maxTimeoutSeconds": 300,
"network": "eip155:137",
"payTo": "0xb531320805C5BED1D46AEaDcF4F008FDF172DBDa",
"scheme": "exact"
},
{
"amount": "20000",
"asset": "0xaf88d065e77c8cC2239327C5EDb3A432268e5831",
"extra": {
"name": "USD Coin",
"version": "2"
},
"maxTimeoutSeconds": 300,
"network": "eip155:42161",
"payTo": "0xb531320805C5BED1D46AEaDcF4F008FDF172DBDa",
"scheme": "exact"
}
],
"description": "ND filter maths: convert between ND factor, stops and optical density, and get the new shutter time with the filter on.",
"extensions": {
"bazaar": {
"info": {
"input": {
"method": "GET",
"queryParams": {
"shutter": "1/60",
"stops": 10
},
"type": "http"
},
"output": {
"example": {
"asOf": "2026-10-11T08:40:15.565Z",
"commonFilters": {
"ND1000": "~10",
"ND2": "1 stop",
"ND4": "2",
"ND64": "6",
"ND64000": "~16",
"ND8": "3"
},
"degraded": false,
"disclaimer": "Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting.",
"duration": "17 s",
"ndFactor": 1024,
"newShutter": "17.1 s",
"newShutterS": 17.066667,
"notChecked": [
"reciprocity failure on film (long exposures need extra time)",
"colour casts and IR leakage of strong filters",
"…1 more"
],
"opticalDensity": 3.0103,
"originalShutterS": 0.016666667,
"reasons": [
"Each stop doubles the exposure time: new time = old time x 2^stops. Optical density = stops x 0.301.",
"Within a normal camera shutter range."
],
"source": "computed locally",
"stops": 10,
"summary": "10 stops = ND1024 = density 3.01: 1/60 s becomes 17.1 s.",
"verdict": "LONG_EXPOSURE"
},
"type": "json"
}
},
"schema": {
"$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"
}
}
},
"lastUpdated": "2026-11-02T04:07:22.307Z",
"quality": {
"l30DaysTotalCalls": 2,
"l30DaysUniquePayers": 1,
"lastCalledAt": "2026-11-02T04:07:22.114Z"
},
"resource": "https://photo-calc.x402tookit.com/nd-filter",
"serviceName": "Photography Calculators",
"tags": [
"photography",
"nd-filter",
"long-exposure",
"calculator"
],
"type": "http",
"x402Version": 2
},
"source": "x402_bazaar",
"summary": "ND filter maths: convert between ND factor, stops and optical density, and get the new shutter time with the filter on."
}What the leaf hashes
{"body":"fc29ac58637bb9684c4420cd13eb0a7ffb700c5bfc6fb374601df13637a0f023","id":2201250,"kind":"listing","method":"sync.x402_bazaar/1","observed_us":1793646803047395,"prev":null,"subject":"x402_bazaar:https://photo-calc.x402tookit.com/nd-filter","subject_kind":"source_record"}Proof
Fold these into the leaf in order, hashing each sorted pair with keccak256, to reach the root of (444186 rows).
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- 0x365b161a4b68d750dcc4b3ecce1154a2163c87b08762079428e68f0ebb6a754e
- Day root
- 0x78fecaabbe319e56f5c4b80fc02e2052e198ad24781da8832a475ff65f2002d1
- Chained
- 0xdc35957db5d1371ca382b9152878ffece28ec7c5cb4f98fd71ddb367f8b999b2
- Published
- On Arc Testnet, block 70432815: 0x56b814612eb2e3e544153df3e91e1f7199106d1e430c7d8c6b653feeb9ebe9af