Fieldring Eyepiece Planner

Eyepiece kit and sky fields

$3.99 · Designed for iPad. Not verified for macOS.

Compare every eyepiece in your case, choose a sky field for tonight and carry a printable optical field card. Fieldring helps visual astronomers choose from the eyepieces they already own. Enter your telescope aperture and focal length, then add eyepiece focal length, apparent field and optional field stop. See magnification, exit pupil and estimated true sky field immediately. Select an eyepiece to view its angular field circle. Compare your whole kit from wide to narrow, or check reference angular spans for the Moon, Pleiades, Orion Nebula and Andromeda. A printable PDF field card lists your optical inputs and calculated results for the telescope case. Share it using the iOS Share sheet. Fieldring is an optical planning aid, not a live sky viewer or a simulation of how bright or detailed an object will appear. Target spans are approximate angular references; actual visibility, seeing, eye relief and illumination are not modeled. When available, a field-stop diameter yields a more direct true-field estimate; otherwise Fieldring uses apparent field divided by magnification. Check maker specifications before use. A new install begins with an empty kit. You may add your own telescope or try a clearly labeled example. All kit data is stored locally. One upfront purchase, no account, subscription, ads, analytics, tracking, cloud processing or developer-server upload.

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The developer, Gobling Company, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .

  • Data Not Collected

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    Accessibility

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    Information

    Seller
    Gobling Company
    Size
    4 MB
    Category
    Utilities
    Compatibility
    Requires iOS 17.0 or later.
    • iPhone
      Requires iOS 17.0 or later.
    • iPad
      Requires iPadOS 17.0 or later.
    • Mac
      Requires macOS 14.0 or later and a Mac with Apple M1 chip or later.
    • Apple Vision
      Requires visionOS 1.0 or later.
    Languages
    English
    Age Rating
    4+
    Copyright
    © 2026 Gobling Company
  • Developer Website
  • Privacy Policy

    • Supports

    • Family Sharing

      Up to six family members can use this app with Family Sharing enabled.

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