Plate solving not working? Fix scale, stars, metadata and field of view
When plate solving fails, the problem is usually not mysterious. Start with pixel scale, field of view, star quality, focus, metadata and image state.
Start with pixel scale and field of view
A plate solver needs a reasonable search area. If the pixel scale or field of view is wrong, the solver may look for the right pattern in the wrong place. This is one of the fastest checks before changing anything else.
- Confirm focal length and camera pixel size.
- Check whether the image was cropped or resized.
- Use a wider scale range when you are unsure.
- Avoid feeding the solver a heavily processed export when a cleaner image is available.
Check star quality
Solvers match star patterns. If stars are trailed, soft, saturated, clipped or hidden by noise, the match becomes weaker. A beautiful nebula preview can still be a bad solving image if the stars are not usable.
Metadata can help or hurt
Approximate coordinates, date, focal length and camera data can speed up solving, but wrong metadata can make the search harder. If a solve fails repeatedly, try a broader search or verify the capture information.
Image state matters
Extreme stretches, compression, strong denoise, aggressive sharpening and very low contrast can all reduce star detection. For troubleshooting, use a clean linear or lightly stretched image where stars are visible without being destroyed.
Quick checklist
- Is the FOV plausible?
- Are stars round and detectable?
- Was the image resized after capture?
- Are coordinates wildly wrong?
- Is the file too noisy, clipped or compressed?
- Does a different frame from the same session solve?