Mobile app overview

The SUNSCAN app, available for Android and iOS, drives the instrument and manages your data: connect the camera, tune the spectrum, record your scans, run the processing, then review and share the images.

This page walks through the four screens of the app. For everything that changed, see What's New in Version 2.1.

Several features in this version need firmware 2.1. The app offers the update as soon as it detects a SUNSCAN that needs it.

1. Home screen

The home screen shows the connection status between the app and the SUNSCAN. Once the link is up, the status indicator turns green: you can connect the camera and start scanning.

There are two ways to connect:

• The SUNSCAN hotspot: power up the instrument, then connect your phone to the sunscan-****** Wi-Fi network.

• Your home Wi-Fi: the SUNSCAN joins your network and the app finds it automatically. This is also what gives it internet access. See Setup.

The screen also shows today's ephemeris: the graph of the Sun's path has been redrawn, and the Sun's altitude and azimuth are now displayed. An alert appears when free storage drops below 5 GB.

The home screen: connection status, free space, the Sun's path, altitude and azimuth.

2. Scan screen

This is where you tune the spectrum and record the scan. Once the camera is connected, a toolbar appears:

• Color: displays the image in color.

• Norm: turns on normalization, either Min/Max or N-th percentile.

• Adjust: opens the advanced settings, covered below.

• Grid: shows a grid to help you align and frame.

• Assist.: opens the scan assistant.

• Ident.: runs spectral line identification.

• AUTO EXP: sets the exposure time automatically.

On the right side of the screen, the crop button moves the crop area up or down. The REC button starts the recording.

Press REC before cropping and a bubble points you to the crop button. Both buttons now show a loading indicator, which prevents a double tap, and the recording timer has been redrawn.

The scan screen and its toolbar.

Scan assistant

Before the scan, the assistant uses your GPS position and the ephemeris to give you the scan duration, the Sun's tilt, how good the observing window is at this hour, and the ideal time slot.

It then guides you live as you place the disk along the slit, with prompts such as "Bring the disk to the mark" and "In position, let the Sun drift off upstream, then record". While recording, a gauge shows the time left and tells you when the disk has finished crossing.

From the observing window to the disk in position, the assistant walks you through the placement.

Spectral line identification

In full-frame mode, mono or color, the app recognises which part of the solar spectrum is on screen and writes the line names straight onto the image: solar lines in amber, telluric lines in blue, key lines in color (Hα, Na D, Mg b, Ca II H & K). The labels follow the zoom.

A banner gives the wavelength range, the dispersion (Å/px) and the number of lines identified. If identification fails, it tells you why: not enough light, saturation, focus.

The Hα region, with H₂O telluric lines in blue.

Auto exposure

In full-frame color mode, the AUTO EXP button adjusts the exposure time on its own. The setting is remembered, and the exposure is locked as soon as you start recording.

AUTO EXP settles the exposure time on its own.

Channel advice

In cropped mode, a banner tells you which Bayer channel will give the better scan: red alone at Hα, blue alone at Ca II H and K, all three channels in between. Tapping applies the change, the cross dismisses the banner. The full behaviour is described on the release page.

The channel advice banner, in cropped mode.

While recording

A thumbnail shows the solar disk building up column by column.

The solar disk builds column by column while recording (video sped up ×2).

Stop the recording a few seconds after the disk has left the slit. Otherwise the automatic stop takes over: a 30 s countdown starts once the disk has finished crossing, then the recording stops by itself. Tapping the countdown cancels it. On by default, it can be turned off in the Settings.

The automatic stop countdown, below the live disk preview thumbnail.

Advanced settings

This panel sets the camera exposure time and gain by hand. Three exposure modes are available:

• Default mode: 20 ms to 160 s.

• SE mode (Short Exposure): 0.1 ms to 20 ms.

• LP mode (Long Exposure): 0.2 s to 30 s.

Press and hold "EXP" to switch modes. A short press opens a numeric keypad: in cropped mode, where the exposure time is set entirely by hand, you type the value in milliseconds, from 0.1 to 30,000 ms, instead of hunting for it with the slider. A short tutorial introduces both gestures the first time.

The two EXP gestures, shown the first time you open the settings in cropped mode.

The "Max ADU" section shows the 12-bit values for each color channel (R, G, B). Tapping a channel displays that channel alone.

The display threshold slider has been rebuilt: more precise on small values, with tick marks and a fine adjustment mode.

Focus assistant

Rebuilt from scratch, it shows a percentage bar of your best score in green, orange or red, along with a curve of the last 20 seconds. A "New best!" message flags every improvement, and a button resets the score.

A 3-step guide walks you through it. The score is smoothed, so one lucky frame no longer sets a record you cannot beat.

The sharpness score rises as you adjust the focus.

For best results: - Use a low gain setting (around 1 dB). - When capturing the Sun in Hα, work exclusively with the red channel. - Avoid overexposing or underexposing your images. A smiley icon indicates whether your exposure is right; it is general guidance, and covers the most common cases.

When the recording ends, the redesigned "Scan complete" dialog lets you tag the spectral line from a grid of colored chips.

3. Gallery

The gallery holds your scans, stacks and animations. It has been redesigned: pill tabs with an item count, rounded thumbnails, colored line badges, animated multiple selection, and a message when it is empty.

The funnel button opens the filters:

• By spectral line: one chip per line, plus a "No line" chip.

• By state: processed, unprocessed, failed.

• By upload: "On SpectroSolHub", "Not yet uploaded".

Each chip shows how many scans it would return. With a filter active, "Select all" picks every filtered scan at once, ready to stack, animate or delete.

Filter by line, by state and by upload, then select them all at once.

The scan screen has been decluttered: secondary actions (spectral line, 3D view, information, processing, download, delete) now sit in a "⋯" menu. The line is picked from the same grid of colored chips as at the end of a scan, even with no SUNSCAN connected.

Processing now reports real progress with the current step, and the reason when it fails. The steps are listed in What's New in Version 2.1.

Downloads now report failures, and on iOS the images go into a "SUNSCAN" album.

A scan screen with its "⋯" menu open: line, 3D view, details, processing, download and delete.

4. Settings

The Settings screen is reorganised into cards:

• Language: languages are now picked with buttons.

• Connection: the SUNSCAN Wi-Fi, to move it onto your home network or back to its hotspot. See Setup.

• SpectroSolHub: your account connection, with the storage and image count used. See Share your images.

• Firmware update: the installed version, the available version, and a one-tap update.

Where to next

These four screens cover a full session, from focusing to sharing your images.

• What's New in Version 2.1: everything that changed.

• Observe: running an observing session.

• Share your images: uploading your scans to SpectroSolHub.