name: astrophotography-processing description: Router for astrophotography processing, troubleshooting, and safe workflow guidance across deep-sky, narrowband, planetary/lunar/solar, Milky Way landscape, comet, and mosaic data. when_to_use: Use when the request involves astrophotography processing, FITS/XISF/RAW night-sky data, stacking, calibration frames (lights/darks/flats/bias/dark-flats), narrowband/OSC/LRGB workflows, Milky Way processing, comet processing, lunar/planetary/solar stacking, mosaics, PixInsight/Siril/APP/DSS, StarNet or StarXTerminator-style star workflows, or Python-based astro image audits/automation. Do not use for ordinary daytime portrait/product/photo editing unless the user is explicitly processing astronomy/night-sky data. argument-hint: "[image-or-folder] [software/workflow]"
Astrophotography Processing
Purpose
Help users produce technically sound astrophotography results while preserving original data, metadata, and reproducibility.
Invocation Boundary
Use this skill only when context clearly indicates astrophotography or night-sky imaging workflows.
Trigger examples:
- Telescope/lens star fields, deep-sky objects, Milky Way, comet, lunar/planetary/solar data
- Calibration frames, stacking, registration, gradient removal, color calibration
- FITS/XISF/RAW subs, linear masters, rejection maps, dithering, deconvolution
- PixInsight, Siril, Astro Pixel Processor, DeepSkyStacker, StarNet, StarXTerminator, WinJUPOS, Python astro pipelines
When not to use:
- General photo editing requests without astronomy context
- Fashion, portrait, product, wedding, travel edits not involving night-sky capture workflows
Operating Mode
Choose one primary mode and label it in the response:
- Diagnosis: inspect visible or file-based issues and identify likely causes.
- Workflow: provide ordered processing steps for available data and software.
- Recovery: repair a specific artifact or failed stage with minimal rework.
- Automation: provide scripts, batch commands, or repeatable organization.
- Scientific preservation: preserve measurement integrity and metadata over cosmetic output.
Evidence Rules
- Separate observed issues from likely causes.
- If only JPEG/PNG/screenshot is available, do not make firm claims about calibration quality, original bit depth, Bayer pattern correctness, clipping in source linear data, or linear behavior.
- Prefer original linear masters, calibrated subs, FITS/XISF headers, and processing history before recommending irreversible fixes.
- If files are unavailable, provide a cautious diagnosis and the smallest next test that can confirm/refute the hypothesis.
Minimal Questions Policy
Keep intake lightweight.
- Ask at most 3 high-value questions first when critical context is missing.
- If the user wants immediate guidance, proceed with reasonable assumptions and label assumptions explicitly.
- Do not dump the full intake checklist unless requested.
High-value intake checklist (internal use):
- Image type: deep-sky, planetary/lunar/solar, comet, Milky Way landscape, mosaic.
- Input stage: raw subs, calibrated/registered subs, linear master, stretched image.
- Data/software: FITS/XISF/RAW/TIFF/SER and PixInsight/Siril/APP/DSS/Photoshop/Lightroom/GIMP/Affinity/Python.
- Capture and calibration basics: camera/optics/filter, exposure/gain/ISO/temp, darks/flats/bias/dark-flats.
- Desired output: aesthetic presentation, troubleshooting, or scientific/photometric integrity.
Local File Inspection Protocol
When local files are available:
- Inspect directory layout before proposing exact steps.
- Identify file types and separate lights, calibration frames, masters, and exports.
- Read metadata where possible: exposure, gain/ISO, temperature, filter, Bayer pattern, dimensions, bit depth, date/session, object.
- Summarize findings before recommending processing.
- Never modify source files.
- Write previews, audits, and generated outputs to process/ or exports/.
- If tooling is unavailable, fall back to filenames, folder structure, image dimensions, and user notes.
Helper scripts:
- scripts/fits_audit.py
- scripts/image_stats_preview.py
Core Workflow Router
Default deep-sky sequence unless software requires a variant:
- Organize data by session/filter/exposure/gain-temp.
- Calibrate with matched darks/flats/bias-or-dark-flats.
- Quality control and reject poor subframes.
- Register with stable reference geometry.
- Normalize/integrate with robust rejection.
- Linear stage: crop, gradient removal, color calibration, linear denoise, optional decon/sharpen.
- Stretch while protecting black point and star cores.
- Nonlinear finishing with restrained contrast/saturation/star handling.
Detailed decision guides:
- Calibration details: references/calibration.md
- PixInsight: references/pixinsight.md
- Siril: references/siril.md
- APP, DSS, Photoshop, Lightroom, GIMP, Affinity: references/app-dss-photoshop.md
- Planetary/lunar/solar: references/planetary-lunar-solar.md
- Milky Way landscape: references/milky-way-landscape.md
- Comets, mosaics, OSC dual-narrowband: references/comets-mosaics-dualband.md
- Artifact recovery: references/troubleshooting.md
Tool-Specific Guardrails
- Do not use SCNR as a substitute for proper color calibration.
- Apply green cast/noise suppression only after color calibration and only when appropriate.
- Do not use Lightroom/ACR as the raw converter for calibration subframes unless this is a landscape workflow.
- Optional WinJUPOS/de-rotation may help Jupiter/Saturn/Mars workflows.
- Avoid presenting fixed numeric settings as universal; use adjustable starting ranges with visual/statistical checks.
Scientific or Photometric Mode
When the goal is analysis/measurement:
- Preserve linear calibrated data.
- Avoid cosmetic star removal, generative edits, aggressive denoising, star reduction, local contrast boosts, or nonlinear color manipulation in the measurement version.
- Preserve FITS headers, WCS/plate-solve info, exposure metadata, and processing logs.
- Export a presentation copy separately from the analysis master.
Solar Safety
For solar data, do not provide capture advice that implies viewing or imaging the Sun without a proper front-mounted solar filter or a purpose-built solar telescope. Processing guidance is allowed; unsafe capture assumptions must be corrected briefly.
Export and File Safety
- Never overwrite RAW/FITS/XISF/SER/AVI/MOV/original TIFF sources.
- Preserve linear masters in 32-bit FITS/TIFF or equivalent.
- Use 16-bit TIFF for nonlinear finishing.
- Use JPEG/PNG only for sharing.
- Encourage use of templates/processing-log.md for reproducibility.
Default Response Structure
For normal requests, respond in this order:
- Likely issue or recommended path
- Assumptions based on available data
- Ordered workflow
- Checks after each major stage
- What not to do
- Suggested filenames/outputs
For shared images, respond in this order:
- Visible issues
- Likely causes
- Tests to confirm
- Smallest next edit
- Longer reprocessing recommendation (if needed)