Dark Sky Meter Pro vs Star Archive

Dark Sky Meter Pro turns your iPhone’s camera into a sky brightness meter. Point at the night sky to get scientific readings in SQM (magnitudes per square arcsecond) and Bortle scale, plus NELM (naked-eye limiting magnitude) and an estimate of visible stars—so you can track light pollution and compare sites. Measure One-tap measurement: cover the lens for a dark frame, then point at the sky. Results in seconds. Device-specific calibration (zero point) for better accuracy; optional FOV setting (default 20° for SQM-style comparison). Readings include location and time for your records. My Data Save measurements locally and, with Sign in with Apple, sync across your devices. Export to CSV for analysis or sharing. Review history with SQM, Bortle, NELM, and location. Clouds Simple cloud forecast for your location so you can plan when to go out. Map See your (and optionally others’) measurements on a map to compare sky quality by place. Info Sunrise, sunset, and darkness window; moon phase, moonrise, and moonset for your location. Built for stargazers, astrophotographers, researchers, and anyone curious about light pollution and dark skies. No extra hardware—just your iPhone.

An app for visual astronomy — observing through a telescope or binoculars with your own eyes. · Sky chart — 5.5 million stars with your own fields of view overlaid, opened from plans, observing and object pages. · Plan and recommend — only what your aperture can show under your site's sky (1,272 objects judged in advance), placed into hour slots, rehearsed on the chart. · Observe and record — step through objects on the chart, check, rate and write; review by night or by object. ■ A built-in sky chart · About 5.5 million stars to 13th magnitude and 16,000+ deep-sky objects. Drag and pinch anywhere. · Sky as it looks right now (zenith up) or north up — one tap on the compass at top left. · Build fields of view from your telescope, eyepieces and finder and overlay several at once. Plan objects as rings, observed ones checked. · Open the chart from a plan, the observing screen or an object page, and come straight back. ■ One unbroken night · Plan — added objects settle into hour slots on their own; drag to rearrange. Tap an object for its altitude curve and suggested magnification right there. · Rehearsal — walk the night on the chart before you leave. Course editing handles hour slots, order and start stars on one screen. · Observing — step through objects on the chart, check them off, rate and write notes. Dictate by voice. · Records — enter the night's conditions once, then review by night or by object. Long-term plans spanning months, too. ■ Data and learning · 2,400+ visual guides — how to find it and what each aperture shows. 4,600+ observing points to rate. · Lists such as Messier, Caldwell, Herschel 400 and 1001, plus your own lists and courses. · Star hopping with 126 routes (using the chart's field-of-view settings); Messier marathon prep and a 110-object night. ■ Also Night mode (red screen, shake to toggle, automatic after sunset) · six themes · sketch albums · eyepiece-view simulator · tonight's clouds and seeing · real-time planets · spreadsheets in and out, full backup · on a bigger screen at starnotearchive.com · Korean, English and Japanese. Free. No ads, no purchases. No account in the app; make a web account only if you want the website. Records stay on your phone; only what you send goes up to the web (site names visible only to you). With weather on, the forecast point's location is passed to the weather service. The 13th-magnitude star data downloads only when you ask. Made as a hobby by one observer.