To create a custom lens or modify existing one, create a json file and place it in the following path of your datapack: data/<pack>/exposure/lens/<lens>.json
To attach lens to a camera, you need to add the item to #exposure:lenses tag.

Example Datapack

Json file has two properties:

• predicate: ItemPredicate, same as in advancements. Used to define valid items for this lens.
• focal_range: FocalRange, min-max values for this lens. Allowed range 10-300.

Example of a wide-angle lens:

{
  "predicate": {
    "items": "minecraft:glass"
  },
  "focal_range": {
    "min": 10,
    "max": 18
  }
}

Example of a prime lens:

{
  "predicate": {
    "items": "minecraft:glass"
  },
  "focal_range": 14
}