Features — Photality

Automated capture

One plan, every phase, fired to the second

Photality models the eclipse the way it actually unfolds — first contact, the partial phases, Baily's Beads, totality, and back out again — and runs the whole sequence on a single clock. You build the exposures once; the app fires each one at the right moment while you watch the sky.

Independent plans per phase. Partiality, Baily's Beads, and totality each get their own exposure design — a repeating bracket (exposure, gain, frame count) or a timed interval — so the fast diamond-ring burst and the long earthshine frame are both handled correctly.
Bracketing across totality's huge dynamic range. A single totality bracket can sweep from the bright inner prominences (very short) out to the faint outer corona and earthshine (seconds long), repeating for as long as your window allows.
Automatic region-of-interest switching. Shoot Baily's Beads on a tight, fast crop, then switch to the full sensor for the corona — Photality changes the ROI mid-event for you, restarting the camera stream cleanly so no frame is lost to the transition.
Contact times computed for your exact site. Enter your coordinates and elevation and Photality calculates your C1–C4 contact moments locally from the eclipse elements — with an optional lunar-limb profile for beads and diamond-ring precision. No internet needed.
Honest duration estimates. The planner counts real per-frame overhead and the cost of each long-exposure stream restart — not just exposure time — so a plan that says it fits your totality window actually fits, and warns you clearly if it doesn't.

Hardware

Full control of ZWO ASI & Player One cameras

Photality talks to ZWO ASI and Player One Astronomy cameras directly — no ASCOM layer, no external drivers, no capture app running underneath. Connect over USB and you have the whole camera.

Every capture control. Exposure, gain, offset, region of interest, binning, and image mode — all in one tab.
Cooling, when your camera has it. Set and hold a target sensor temperature on cooled models; the control only appears when the camera actually has a cooler.
A live preview that shows real color. Color sensors are debayered and white-balanced on the fly, with a monochrome fallback for narrowband light — while the data saved to disk stays completely untouched.
"Bad cable" detection. A USB-3 camera that negotiated down to USB-2 — the classic charge-only-cable trap that quietly cripples frame rates — is flagged the moment you connect.
Per-camera profiles. Settings, optics, cooling preference, and the benchmark are saved per physical camera by serial number, and restored automatically when you plug it back in.
A real throughput benchmark. Photality measures your camera's actual readout time across resolutions and modes and fits a model of it — so every step's predicted timing reflects your hardware, not a guess.

Why the benchmark matters. Cameras differ in what limits their frame rate — some are bound by sensor rows, others by total pixels. Photality measures which, so its timing predictions (and its "will this plan fit?" warnings) are grounded in your camera's real behavior rather than an optimistic spec-sheet number.

Sharpness

Get focus right — and keep it there

Focus is the quietest way to lose an eclipse: nothing looks wrong on a small screen until you're home. Photality gives you a live sharpness read for manual focusing, and full automation if you have a supported electronic focuser.

Live sharpness score. A real-time focus metric on the preview, so even manual focusers get objective feedback instead of a guess through a loupe.
One-click autofocus. New in 0.94 With an Astroasis Rose electronic focuser, Photality runs a noise-aware search that maps your focus curve and drives to its true peak — no hunting, no premature stops.
Save a Focus Point, return any time. Store best focus per camera and snap back to it with one click — even in the middle of a running capture, if you nudged something.
Focus that tracks the temperature. Experimental As the air cools toward totality the focus point drifts. An optional mode re-tunes focus in the quiet gaps between partial-phase frames — under hard deadlines, so it can never delay or disrupt your plan, and always returns to the best-known position if it runs out of time.

Built for the unrepeatable

What happens when something goes wrong

This is where Photality spends most of its engineering. Totality doesn't wait for you to troubleshoot, so the app is designed to survive the failures that actually strike in the field — and to degrade to "lost a frame," never "lost the eclipse."

Pre-flight readiness check. When you arm a plan, Photality reviews camera link, benchmark, focuser, saved focus, contact times, disk space, backup folder, write speed, audio, and AC power. Nothing hard-blocks — the person at the telescope always outranks a checklist — but nothing catches you by surprise either.
Disk-space protection. A pre-flight estimate warns if your plan won't fit the free space, and a live guard fires once if space runs low mid-capture — with room left for the write queue to drain.
Automatic backup-folder failover. Point Photality at a backup output folder and it switches to it automatically if the primary volume starts failing, ejects, or fills — carrying the run log with it and retrying the frames that were in flight.
Slow-disk failover. A too-slow disk never errors — it just silently throttles your capture to its own speed. Photality measures write speed before you start and watches for sustained stalls during the run, switching to the backup before a slow card quietly steals your frame count.
Memory-bounded back-pressure. Under a burst, in-flight saves are capped so a fast camera can never outrun the disk into an out-of-memory crash.
USB disconnect recovery. A cable knocked loose mid-event is detected, reconnected, reconfigured, and resumed — so a bumped tripod leg doesn't end the shot.
Crash and resume. If the app or Mac goes down mid-capture, relaunching offers to resume into the same session folder, picking up where it left off.
A forensic run log. Every real capture writes a full log — every event, warning, and error — into the session folder, so you can reconstruct exactly what happened after the event is over.
Spoken alerts, kept useful. Contact-time countdowns, filter reminders, and failure alerts are spoken aloud in short, plain phrases you can act on without looking at the screen.

A note on the spoken filter reminders. They're a convenience to help you keep your own checklist — not a safety device. Solar viewing and imaging demand certified solar filtration, and you remain responsible for using it correctly at every moment the sun's disk is exposed. Never rely on software to tell you when it's safe to look or to remove a filter.

Confidence before the day

Rehearse the whole thing first

The single best predictor of a good eclipse capture is a full dress rehearsal — and Photality is built to give you a real one, not a simulation with fake data.

End-to-end rehearsal mode. Run the entire first-contact-to-fourth-contact sequence at accelerated speed, with your real camera producing real frames written to real disk — so you're exercising the exact path you'll run on eclipse day.
Rehearse the failures too. Because the reliability paths are real, you can rehearse them: yank the USB cable and watch it reconnect, fill a small disk and watch the backup take over, force-quit and watch it resume.
Timing you can trust. The same throughput model and honest duration math that plan your capture also drive the rehearsal, so what you verify at home is what runs in the field.

Your data

Standard files, portable plans

Photality captures into the formats professional astrophotography tools already speak, and lets you carry your work between machines.

XISF and FITS output. Save frames in either format, complete with capture metadata — ready to stack in PixInsight, Siril, or any standard workflow.
Full-resolution raw data. Everything saved to disk is the untouched sensor data; the on-screen color processing is display-only and never alters your files.
Import and export capture plans. Build your plan on one Mac and carry it to another — useful for prepping at home and running a different machine in the field.
Organized sessions. Each run lands in its own dated session folder alongside its run log, so your beads, totality, and partial frames stay sorted.

The foundation

Native, private, and free

Photality is a native Mac app, built in Swift and SwiftUI for Apple Silicon — not a cross-platform port, not a Python stack, not a browser in a window.

Apple Silicon native. No Rosetta, no plugins, no drivers to install. Open it and connect your camera.
Zero system permissions. Photality asks for no location, no notifications, nothing — you enter your coordinates by hand, by design.
Works fully offline. The only time Photality touches the network is an optional check for its own updates. At your dark-sky site it needs nothing.
Free, for every eclipse. No license, no paywall, all cameras included. If it helped you capture totality, there's an optional tip jar — never required.

Everything Photality does

One plan, every phase, fired to the second

Full control of ZWO ASI & Player One cameras

Get focus right — and keep it there

What happens when something goes wrong

Rehearse the whole thing first

Standard files, portable plans

Native, private, and free

Ready to rehearse your eclipse?