If LinearFit fails (which happens if your noise floor is too high), you need a manual PixelMath link. This is often required for overexposed stars or heavily vignetted edges.
: Applies the same stretching parameters to all three color channels simultaneously. This is the default but often results in a heavy green or red cast if the background levels are not naturally balanced. Unlinked Stretch (Lerar/Link workaround) : By clicking the STF icon while holding the pixinsight lerar link
Before adjusting any settings, it is crucial to understand the state of your data. When you finish stacking raw light frames using tools like the Weighted Batch Preprocessing (WBPP) script, your master image is . Linear Fit (RGB) | PixInsight Forum If LinearFit fails (which happens if your noise
First, let’s address the keyword. Searching forums like Cloudy Nights or the official PixInsight Forum reveals that “Lerar” is likely a misspelling of: This is the default but often results in
This is the most common and frustrating error. It appears when PixInsight cannot find an .xnml file that corresponds to an image in your input list. This happens for two primary reasons:
If you apply an , PixInsight stretches the massive surplus of green data by the exact same multiplier as the starved red and blue data. The result is an overwhelming, ugly green cast over your entire nebula or galaxy. Alternatively, if you are utilizing specific light-pollution filters or multi-narrowband dual filters (like an L-eNhance or L-eXtreme), the image will often render with a blinding purple or pink hue. Step-by-Step: How to Use the STF Link/Unlink Function
With your channels linked and balanced, you can safely transfer the STF settings to the tool to permanently stretch your image into a non-linear state, ready for final detailing. Conclusion