Telescope Eyepiece Calculator

Name: Telescope Eyepiece Calculator
Rating: 1 (1 reviews)
Author: Cederic Schmid

Magnification & TFOV

Free · In‑App Purchases · Designed for iPad

1 Rating
Ages

4+
Years
Category

Reference
Developer

Cederic Schmid
Language

EN
+ 22 More
Size

12.8
MB

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.

Events

SPECIAL EVENT

Winter Deep-Sky Planning

Plan winter deep-sky sessions. Compare eyepieces for iconic targets, organize setups in Cases & export field guides.
SPECIAL EVENT

Comet Observation Prep

Optimize for comet tracking. Calculate low-power TFOV, compare wide-field eyepieces & plan sessions for extended objects

Ratings & Reviews

1.0

out of 5

1 Ratings

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.