Capturing & Processing the Sun – A Complete White-Light Imaging Workflow

☀️ A Beginner’s Guide to White‑Light Solar Imaging

We’re capturing sharp, colourised images of the Sun using a short high‑fps video and post‑processing — a method that outperforms in‑app stacking. Let’s walk through it.

🔭 What You’ll Need

• • Tripod: Stable and level.
  • Telescope: With securely mounted white‑light solar filter or Herschel wedge. Smart scopes like the Seestar S50 have built-in filters — ensure they are active.
  • Equatorial wedge (optional): Helps reduce field rotation in EQ mode.
  • Star tracker (optional): Keeps the Sun centred in longer sessions.
  • Camera: Preferably high‑fps mono (e.g. ZWO ASI 174 MM, Player One Apollo‑M Mini).
  • Capture software: FireCapture, SharpCap, NINA, or native app for smart scopes.

🔥 Why We Recommend FireCapture

FireCapture is purpose-built for solar, lunar, and planetary imaging. It’s widely regarded as one of the best capture applications available for amateur astrophotographers using high-speed mono or colour astronomy cameras. Here’s why it stands out:

• • • ✅ Native support for most ZWO, Player One, QHY, and other astronomy cameras.
    • ✅ Real-time histograms, gain/exposure adjustment, and solar-specific capture tools.
    • ✅ ROI (Region of Interest) mode to boost frame rates by capturing a smaller portion of the sensor.
    • ✅ Automatic file naming and capture logging for organisation and repeatability.
    • ✅ Excellent support for RAW .SER format — the best format for solar imaging and stacking.
    • ✅ Optional scripting, dark/flat frame capture, and even planetary ephemeris overlays.

It’s free, regularly updated, and widely used by solar imagers worldwide. If your camera is supported, FireCapture should be your default capture tool.

• Solar filter: Mandatory — Baader film, glass, or internal factory options.

🎞️ Capture Settings & Video Format

• Format: Use .SER or uncompressed .AVI. These retain all raw frames without compression. Avoid .MP4 or .MOV — they’re lossy and unsuitable for stacking.
• Resolution: Use the camera’s native resolution. Avoid digital zoom or pixel binning unless your system struggles with bandwidth.
• Frame Rate: Target 100+ fps if your camera and system can handle it. More frames = better stacking.
• Capture Length: 30–90 seconds — long enough for statistical stacking, short enough to avoid atmospheric smearing.
• Bit Depth: Prefer 8‑bit or 16‑bit monochrome. 16‑bit retains subtle tone detail but produces larger files.
• Codec: For .AVI, choose uncompressed or use a lossless codec like Lagarith or UTVideo if supported. Never use H.264 or MPEG.
• File Naming: Use a logical naming structure (e.g. Sun_2025-08-04_0855UTC.SER) to help with batch processing later.
• Tracking Mode: Short Alt/Az clips are fine for 60–90 seconds. EQ or star tracking helps keep the disc centred, which can improve stacking accuracy.

🧪 Suggested Camera Settings

• Gain: Start moderate — avoid saturation. Adjust as needed for histogram balance.
• Exposure: Typically 0.5–3 ms — just enough to expose granulation without blur.
• Histogram: Aim for 70–80% peak. Avoid overexposing bright regions.
• Gamma: Default for capture. Adjust during processing, not live.
• Focus: Zoom into live view. Adjust until surface texture is crisp. A Bahtinov mask can help.

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🧪 Part 1: Image Acquisition

🛠️ Step‑by‑Step Setup

1. Place and level your tripod.
2. Attach your telescope securely.
3. Attach filter before aiming.
4. Fit equatorial wedge if using EQ mode.
5. Rough polar align or use solar finder/shadow.
6. Connect camera and launch capture software.
7. Centre and focus the Sun using live‑view tools.

📷 DSLR Imaging Option

If you only have a DSLR or mirrorless camera with a suitable solar filter, you can still participate:

• Use live‑view to visually focus on the solar surface with filter attached.
• Capture a series of short exposure stills (e.g. 1/500–1/2000 s) or burst video if supported.
• Process these in PIPP and AutoStakkert just as you would with AVI stacks.
• Then finish off in ImPPG or standard editing software.

💡 Tools for Every Setup

• NINA: Great for capturing SER or AVI format using DSLRs or astronomy cameras. Offers precise control over framing and exposure.
• PIPP: Trims, centres, crops, and filters frames for stacking.
• AutoStakkert!: Aligns and stacks with sub‑pixel precision.
• ImPPG: A free solar processing tool — ideal for sharpening, tone curve adjustments, and final tweaks if you don’t use Photoshop or PixInsight.

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🧬 Part 2: Image Processing

🔧 PIPP Tab Settings (Tab‑by‑Tab)

PIPP guides you through seven tabs. For solar full-disc imaging, configure as follows:

• Source Files: Add your RAW SER or AVI video.
• Input Options: Leave default unless colour conversion needed.
• Processing Options: Select “Solar/Lunar Full Disc”, tick “Centre object” and “Enable cropping”, and define crop area around the disc.
• Quality Options: Enable quality estimation. Reject the worst 10–30% of frames.
• Animation Options: Skip — not needed for still image processing.
• Output Options: Choose SER or cropped AVI. SER preferred for stacking in AutoStakkert.
• Do Processing: Run a test, then process all frames with crop and quality selection applied.

📊 Stacking with AutoStakkert

1. Open the SER file.
2. Select “Surface” mode.
3. Click “Analyse”.
4. Add alignment points manually or let AS! choose them automatically.
5. Choose best frames to stack (10–25%).
6. Click “Stack” — your TIFF will be saved to the output folder.

🎨 Final Editing & Colour

1. Open your stacked TIFF in ImPPG, Photoshop, or PixInsight.
2. Convert to RGB if mono.
3. Apply curves, tone adjustments, and mild sharpening.
4. Optionally add colour using gradient maps or overlays.
5. Fine-tune contrast and detail.
6. Export your final image.

📌 Why It Outperforms In‑App Stacking

• Smart-scope apps stack heavily compressed JPEGs — often capped at lower frame rates and basic alignment.
• Our method uses high‑frame‑rate raw data, filters out bad frames, and preserves maximum resolution.
• This lets you pull out granulation, sunspot structure, and finer limb detail not possible in-app.

🔍 What Success Looks Like

Well-processed solar images will reveal:

• Granulation across the disc (solar surface texture).
• Dark sunspots with crisp penumbra and umbra zones.
• Clean limb edge — free from artefacts and noise.

If you’re missing these, revisit focus, stacking ratio, or capture settings. Improvements come quickly with practice.

🧭 Final Tips

• Focus is everything — check live view before recording.
• Record short clips to reduce atmospheric distortion.
• Avoid midday — morning seeing is usually better.
• Clean optics and double-check filter before each session.
• Save raw files — future processing will improve as your skills do.

This method unlocks solar detail far beyond in-app stacking — and once you see the results, you won’t go back. Happy imaging!

🎥 Watch: Solar Imaging Walkthrough by Cosmic Photons

This video by Cosmic Photons complements the written guide. It’s a great visual reference for setup and imaging: