{
  "input": {
    "name": "Backyard session",
    "scope": {
      "name": "200 mm reflector",
      "aperture_mm": 200,
      "focal_mm": 1000
    },
    "factor": 1,
    "eyepieces": [
      {
        "name": "Wide 25",
        "focal_mm": 25,
        "afov_deg": 60
      },
      {
        "name": "Detail 10",
        "focal_mm": 10,
        "afov_deg": 60
      }
    ],
    "targets": [
      {
        "name": "My 60 arcminute target",
        "size_arcmin": 60
      },
      {
        "name": "My 90 arcminute target",
        "size_arcmin": 90
      }
    ],
    "margin": 1.2
  },
  "deck": {
    "version": "1.0.0",
    "name": "Backyard session",
    "scope": {
      "name": "200 mm reflector",
      "aperture_mm": 200,
      "focal_mm": 1000,
      "effective_focal_mm": 1000
    },
    "factor": 1,
    "margin": 1.2,
    "eyepieces": [
      {
        "index": 0,
        "name": "Wide 25",
        "focal_mm": 25,
        "magnification": 40,
        "exit_pupil_mm": 5,
        "true_field_deg": 1.5,
        "true_field_arcmin": 90,
        "field_method": "apparent_field_approximation"
      },
      {
        "index": 1,
        "name": "Detail 10",
        "focal_mm": 10,
        "magnification": 100,
        "exit_pupil_mm": 2,
        "true_field_deg": 0.6,
        "true_field_arcmin": 36,
        "field_method": "apparent_field_approximation"
      }
    ],
    "targets": [
      {
        "name": "My 60 arcminute target",
        "size_arcmin": 60,
        "required_field_arcmin": 72,
        "fitting_eyepiece_indices": [
          0
        ],
        "suggested_index": 0,
        "geometric_fit": true
      },
      {
        "name": "My 90 arcminute target",
        "size_arcmin": 90,
        "required_field_arcmin": 108,
        "fitting_eyepiece_indices": [],
        "suggested_index": null,
        "geometric_fit": false
      }
    ],
    "limits": [
      "Field of view is an estimate; distortion and telescope vignetting are not modeled.",
      "Geometric fit does not predict visibility, seeing, sky brightness, altitude or image quality.",
      "Target angular sizes are supplied by you; this is not a sky catalog."
    ],
    "sources": [
      {
        "url": "https://www.televue.com/engine/TV3b_page.asp?id=79",
        "label": "Tele Vue: choosing eyepieces — magnification, field stop and exit pupil"
      },
      {
        "url": "https://www.celestron.com/products/nexstar-8se-computerized-telescope",
        "label": "Celestron NexStar 8SE: 2032 mm focal length and 25 mm eyepiece, 81x specified"
      }
    ]
  }
}