# Telescope Eyepiece Calculator — Magnification & TFOV > Offline calculator for telescope magnification, field of view, and eyepiece performance. (iPhone/iPad app by Cederic Schmid.) - Source: https://appshunter.io/ios/app/telescope-eyepiece-calculator/id6751347841 (this page in markdown: same URL + `.md`) - Developer: [Cederic Schmid](https://appshunter.io/developer/1833020611) - Category: Reference, Utilities - Price: Free with in-app purchases - Rating: 1.00/5 from 1 App Store ratings - Age rating: 4+ - Requires: iOS 18.5 · 12 MB - Languages: American English, Arabic, Czech, Danish, Dutch, French (France), German (Germany), Greek, Hebrew, Indonesian and 13 more - Released: 2025-08-24 - Data updated: 2026-07-29 - Monetization: free with in-app purchases - User reviews in markdown: https://appshunter.io/ios/app/telescope-eyepiece-calculator/id6751347841/reviews.md ## What is Telescope Eyepiece Calculator? Telescope Eyepiece Calculator is a professional, 100% offline tool for astronomers and serious stargazers. Enter your telescope aperture and focal length, pick an eyepiece (Plössl, Wide, UWA, Hyper, or custom), and instantly see magnification, exit pupil, true field of view (TFOV), and f-ratio: all with a clean, night-friendly design. Why it’s useful • Choose the right eyepiece faster: live results as you type. • Avoid weak or mushy views: color badges warn about over/under magnification and tiny exit pupils. • Plan smarter sessions: see TFOV, power category (Low/Medium/High), and the effect of Barlow/Reducer multipliers. Free Features • Telescope aperture & focal length (mm/inches) • Eyepiece focal length and type presets • Barlow/Reducer support with custom multipliers • Magnification, Exit Pupil, TFOV, f-ratio (real-time) • Power category (Low/Medium/High) • Night Mode + haptic feedback • One Equipment Case (save your default setup) • Works fully offline. No accounts. No tracking. Pro Features (one-time upgrade) • Unlimited Cases: organize multiple telescopes & eyepieces • Side-by-Side Compare: evaluate two eyepieces at once • Precision Field-Stop TFOV: field-stop diameter for ultra-accurate TFOV • Quick Sets: one-tap telescope + Barlow combos • Premium Themes: Glass, AMOLED, Space Gray + adjustable haptics • PDF Export: share a clean session setup card • Smart Hints: color-coded warnings for over/under magnification Built for iPhone and iPad with a crisp interface that’s easy on the eyes at the scope, whether you’re viewing planets, the Moon, or wide-field deep-sky objects. ## Key features - Real-time magnification calculation - True Field of View (TFOV) display - Exit pupil and f-ratio calculation - Eyepiece type presets - Night-friendly design - Offline functionality - Equipment case for saving setups ## Pricing and in-app purchases Base price: Free. **Subscriptions** | Subscription | Price | Period | | --- | --- | --- | | Plus Weekly | $0.99 | per 7 days | | Plus Monthly | $2.99 | per month | **One-time purchases** | Purchase | Price | Type | | --- | --- | --- | | Pro Upgrade | $4.99 | one-time | ## Frequently asked questions about Telescope Eyepiece Calculator ### What is the Telescope Eyepiece Calculator? Telescope Eyepiece Calculator is a 100% offline tool for astronomers that calculates magnification, exit pupil, true field of view (TFOV), and f-ratio based on your telescope and eyepiece specifications. ### Does Telescope Eyepiece Calculator work offline? Yes, Telescope Eyepiece Calculator is designed to work fully offline. It does not require an internet connection, accounts, or tracking, making it ideal for use in remote observing locations. ### What are the Pro features in Telescope Eyepiece Calculator? The Pro features, available via a one-time upgrade, include unlimited equipment cases, side-by-side eyepiece comparison, precision field-stop TFOV, quick telescope and Barlow combos, premium themes, PDF export, and smart hints. ### How does Telescope Eyepiece Calculator help avoid poor views? The app provides color badges that warn about over/under magnification and tiny exit pupils, helping users select the right eyepiece for optimal viewing conditions and avoid weak or mushy views. ### What devices is Telescope Eyepiece Calculator available on? Telescope Eyepiece Calculator is built for iPhone and iPad, offering a crisp interface that is easy on the eyes during stargazing sessions. ### What is the pricing for Telescope Eyepiece Calculator? The basic version of Telescope Eyepiece Calculator is free. There are optional subscription plans available, including 'Plus Weekly' for $0.99/P7D and 'Plus Monthly' for $2.99/P1M, both offering a 7-day free trial. ### How often is Telescope Eyepiece Calculator updated? The latest version is 1.2, and the app was last updated on January 5, 2026. This indicates a relatively recent update, suggesting ongoing development and support. ### What is the age rating for Telescope Eyepiece Calculator? Telescope Eyepiece Calculator has an age rating of 4+, making it suitable for a wide range of users interested in astronomy. ## Version history (last 3 releases) ### 1.2 — 2026-01-05 I have been working hard to make this the ultimate tool for astronomers. Version 1.2 is a massive update, and I'm excited to share these new features with you: Apple Watch Companion App I've built a brand new Apple Watch app from scratch! Now you can check your magnification, exit pupil, and true field of view right from your wrist while you're at the telescope. No need to unlock your phone in the dark. Visual Target Simulator I added a new "Simulator" view that shows you exactly how big objects like the Moon, Jupiter, Saturn, and the Orion Nebula will look in your eyepiece. Compare "True Field of View" against famous targets to know if they'll fit! Eyepiece Comparison Tool I created a powerful new "Compare" tab. - Side-by-Side: See two eyepieces next to each other to compare stats. - FOV Overlay: Visualize the difference in field of view directly. Professional PDF Reports I completely overhauled the "Export Setup Card". It now generates a beautiful, print-ready PDF report (A4/Letter) with all your equipment details, visual metrics, and advanced deep-sky performance stats. Perfect for your logbook or sharing with friends. 24 Languages Support I have localized the app into 24 different languages, ensuring that astronomers around the world can use the tool in their native tongue. Improvements & Fixes - Pro Metrics: Added "Limiting Magnitude" and "Resolution" calculations to the main view. - Interaction: Improved the "Equipment Cases" list, just tap to apply a whole setup instantly. - Refinement: Polished the UI and fixed several bugs for a smoother experience. Thank you for using Telescope Eyepiece Calculator! If you enjoy this update, please consider leaving a review, it really helps me out. ### 1.1 — 2025-09-22 • Full iPad support with a native split layout • Improved themes with clearer previews and polish • 24-language localization for a truly global UI • Refined Settings & Pro screen with region-aware pricing • Better keyboard handling and smoother haptics • Many small UI fixes and performance improvements ### 1.0 — 2025-08-24 No release notes. ## Apps similar to Telescope Eyepiece Calculator | App | Rating | Price | Category | | --- | --- | --- | --- | | [Our Night Sky](https://appshunter.io/ios/app/our-night-sky/id6751737620) | 5.0 (1) | Free | Reference | | [Space App \| Probes & Orbiters](https://appshunter.io/ios/app/space-app-probes-and-orbiters/id6745748966) | — | Free | Reference | ## More apps by Cederic Schmid - [Concrete Calculator Pro.](https://appshunter.io/ios/app/concrete-calculator-pro/id6749963303) - [Irrigation Calculator Pro](https://appshunter.io/ios/app/irrigation-calculator-pro/id6751106220) - [Klabim](https://appshunter.io/ios/app/klabim/id6751127127) - [Cocktail Calculator Pro](https://appshunter.io/ios/app/cocktail-calculator-pro/id6751190590) - [Master Cheats](https://appshunter.io/ios/app/master-cheats/id6751210646) - [Video Size Calculator Pro](https://appshunter.io/ios/app/video-size-calculator-pro/id6751235728) All apps by Cederic Schmid: https://appshunter.io/developer/1833020611 --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-07-29.*