Frequently Asked Questions

Below you'll find answers to the most common questions about Astro Live Stacker (ALS). If you don't find what you're looking for, open an issue on GitHub or reach out via the community channels.

🧩 General

What is Astro Live Stacker (ALS)?

ALS is a real-time astrophotography tool that aligns and stacks images on the fly to improve signal-to-noise ratio and reveal faint details during live sessions.

Which operating systems are supported?

ALS runs on Windows, Linux, macOS, and Raspberry Pi (64-bit). Each platform provides a native build for best performance.

Is ALS open source?

Yes. ALS is fully open source under the GPL v3 license. You can find the source code on GitHub.

Can I use ALS without an internet connection?

Yes — all image acquisition and stacking functions work offline. Only optional features like remote viewing via the integrated web server need local-network access.

Does ALS handle image capture?

NO. ALS only pools a user defined folder for new subs

🔭 Installation & Setup

How do I install ALS on my system?

Each release includes platform-specific installers or archives. Refer to the Installation Guide for detailed steps and dependencies.

How do I update ALS to the latest version?

Download the latest release from the official homepage and replace the previous installation. Your previous settings are preserved.

Do I need administrator privileges?

Only for installation on Windows systems. Normal use doesn’t require elevated privileges.

🖥️ Interface & Usage

Where are my stacked images saved?

By default, results are written to the Work Folder. You can change this path in Preferences → Output.

Can I adjust color balance or stretch while stacking?

Yes — the Processing panel provides live controls for RGB Balance, Levels, and Auto-Stretch.

Why is the image dark or noisy at the beginning?

Early frames have little data. As stacking proceeds, noise averages out and faint details emerge progressively.

What does “Align” do?

ALS automatically detects stars in each frame and aligns them before stacking, compensating for tracking errors and field rotations.

⚙️ Technical & Performance

Why does ALS use a lot of CPU

Real-time stacking and preview rendering are computationally intensive. Use longer exposures to reduce overall load.

Does ALS use my GPU?

No. But future versions will surely leverage GPU power

How can I reduce memory usage?

The only factor for memory use is frame size. Capturing smaller subs reduces memory load

🌐 Remote Access & Sharing

What is the integrated web server?

It’s a lightweight HTTP server that lets you view the live-stacking session from any device on your local network.

How do I connect from another device?

From a browser, enter the address shown in the ALS status bar (e.g. http://192.168.1.42:8000) or flash the QR code available while the server is running.

🪲 Troubleshooting

The stack looks misaligned or blurred.

Here are common causes:
  • Drift during sub exposure
  • Poor focus.
  • Low star count in frames.

Why are some frames rejected?

ALS filters out frames with low star detection confidence

You can lower the alignment threshold in the Main controls panel to reduce subs rejection, at the risk of including misaligned frames.

My dark aren’t applied.

Check the session log to get the root cause of missed or skipped dark subtraction

💾 File Formats & Compatibility

Which formats are supported?

ALS reads :
  • FITS (file extensions : .fits, .fit, .fts)
  • Raw files from all common DSLRs
  • TIFF
  • PNG
  • JPEG
ALS writes :
  • JPEG
  • TIFF
  • PNG

💬 Community & Support

Where can I report a bug or request a feature?

Use the GitHub Issues page.

Is there a user manual?

Yes — full documentation is available at https://als-app.org/docs/v0.7/

How can I contribute?

You’re welcome to submit pull requests or translations!