TrueField Optics Bench

Assemble telescope, Barlow, eyepiece, and filter—then see live magnification, true FOV, exit pupil, and target-fit ratings. Offline catalogs, multi-rig charts, and sharea

TrueField Optics Bench is an offline-first workbench for amateur astronomers, club mentors, and new scope owners who want clear go/no-go framing decisions before they step outside.

Stop juggling spreadsheets, scattered charts, and guesswork. Assemble a full optical train—OTA, optional Barlow or focal reducer, eyepiece, and filter—then instantly read the numbers that matter: magnification, true field of view (degrees and arcminutes), exit pupil, f-ratio, Dawes and Rayleigh limits, and maximum useful magnification, with color-coded comfort bands.

FINISHED CATALOGS, CUSTOM GLASS Browse 60+ common amateur OTAs and 80+ eyepieces (Plössl, wide-field, planetary, zoom) with real focal lengths and apparent fields. Filter by type, aperture class, or budget tier. Missing a piece? Add custom specs in seconds and keep them on your device.

SEE THE FRAME, NOT JUST THE MATH Open the FOV visualizer: a true-field disk drawn to scale against a full-moon reference, with optional secondary disks so lunar, planetary, and deep-sky framing is obvious at a glance.

TARGET FIT ADVISOR Pick an object class—Moon, planets, open cluster, globular, bright nebula, or galaxy—and get green, amber, or red fit ratings that compare your exit pupil and true FOV to typical angular sizes and recommended pupils for that class.

COMPARE RIGS, PACK WITH CONFIDENCE Place up to three named trains side by side on shared charts (magnification, true FOV, exit pupil, light-grasp index) so you know which eyepiece bag to take on a given night.

LOCAL RIGS THAT STICK Save unlimited named setups (for example, “Grab-and-go 80mm + 24mm”), pin one Active Rig, duplicate or edit trains, and restore everything after relaunch. Data lives in on-device storage—no account, no cloud, no network required.

SHAREABLE FOV PREP CARDS Export a one-page PDF with rig summary, metrics table, and moon-scale diagram via the system share sheet for club nights or printed eyepiece cases.

BUILT FOR REAL SESSIONS • Home-screen widget: Active Rig name, magnification, true FOV, and exit pupil at a glance • Shortcuts action: compute true FOV from a saved rig without opening the full UI • Units (metric/imperial), Dynamic Type-friendly text, light/dark high-contrast palettes • In-app Privacy Policy and Terms: on-device-only processing, no analytics

Educational note: results are optical geometry from the train you enter. They are not weather, seeing, collimation, or mount advice.

Know exactly how any eyepiece will frame the sky on your scope—in seconds, offline, with catalogs and cards you can take to the field.