Telescope Collimation Lab

Keep your star-test photos and centering measurements together. Telescope Collimation Lab is a one-time paid, offline notebook for documenting telescope centering work. Import a PNG or JPEG through Files, then explicitly mark the reference ring center, inner-feature center and ring edge. The app calculates their image-plane offset as a percentage of your marked reference radius. MEASURE WITH THE PHOTO Place three points, inspect at 2× view, enter precise X/Y coordinates, nudge by one working pixel and undo placements. The original image is retained byte-for-byte with a SHA-256 checksum. EXIF orientation is applied to the working preview; large images are reduced to a maximum 2048-pixel working edge. Coordinates refer to that working image, with source and working dimensions shown. COMPARE YOUR ROUNDS Choose before and after rounds, view their marked photos and compare centering values. Keep labels, focus-side notes, seeing and magnification. Manual numeric rounds are available when you already have measured offsets and radius in matching units. Existing 1.0 records remain available; legacy values are not reverified. New sessions contain no invented measurements. EXPORT THE RECORD Create annotated PNGs, a PDF with every round, a complete measurement CSV, a restorable JSON backup and a ZIP containing the original sources and a SHA-256 manifest. Export files are created in separate directories so later exports do not overwrite earlier output. Import a JSON backup as a separate restored session. PDF notes may be shortened with a continuation label; CSV and JSON retain the full notes. BUILT FOR PHONE AND IPAD The iPad places the image beside its measurement details. Save multiple telescope sessions, edit notes, duplicate a session and explicitly confirm deletion. A clearly labeled original synthetic ring study lets you explore the workflow without pretending it is an observed star or an optical simulation. FORMAT AND STORAGE LIMITS Single still PNG or JPEG, 8 MB maximum, 32 pixels minimum and 30 megapixels maximum. Up to 100 sessions, 500 rounds per session and 128 MB of retained photo storage. JSON backup import is limited to 180 MB. No FITS, RAW, video, camera capture, automatic ring detection or cloud synchronization. MEASUREMENT SCOPE This is manual image-plane geometry, not an optical pass/fail test, sky bearing or calibrated screw-turn calculator. A smaller marked offset alone does not establish collimation. Focus, seeing, reference-ring selection, image scale and orientation affect comparisons. Follow your telescope maker’s procedure, make appropriate small changes and re-center the star between observations. No account, subscription, in-app purchase, ads, analytics, tracking or developer upload. Sharing and importing files are your choice. Local device backups may include your saved data according to your system settings.