{
  "annotation_id": "4707f996-8d8d-49fd-ad53-3dc92d625b78",
  "date_created": "2026-03-02T18:00:39.429000Z",
  "date_modified": "2026-03-02T18:00:39.429000Z",
  "file_hash": "334e9746f22efd455d3919898a9b4c5afd33ecf5a7b2bf8ecc3abdf74c548cbf",
  "private": false,
  "record": {
    "abstract": "A perfect focus telescope is one in which all rays parallel to the axis meet\nat a point and give equal magnification there. It is shown that these two\nconditions define the shapes of both primary and secondary mirrors. Apart from\nscale, the solution depends upon two parameters, $s$, which gives the mirror\nseparation in terms of the effective focal length, and $K$, which gives the\nrelative position of the final focus in that unit. The two conditions ensure\nthat the optical systems have neither spherical aberration nor coma, no matter\nhow fast the $f$ ratio. All known coma--free systems emerge as approximate\nspecial cases. In his classical paper, K. Schwarzschild studied all two mirror\nsystems whose profiles were conic sections. We make no such a priori shape\nconditions but demand a perfect focus and solve for the mirrors\u0027 shapes.",
    "arxiv_id": "physics/0203082",
    "authors": [
      "D. Lynden-Bell"
    ],
    "categories": [
      "physics.optics"
    ],
    "doi": "10.1046/j.1365-8711.2002.05486.x",
    "title": "Exact Optics: A unification of optical telescope design",
    "url": "https://arxiv.org/abs/physics/0203082"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "92cf32f6-77c6-4945-85ea-50bb04c4b84e",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}