In the Screen Transfer Function (STF), the Link RGB Channels button (represented by a small chain icon in the top left of the STF window) determines how PixInsight calculates an automatic stretch for your image.
Linked Mode (ON): PixInsight applies the same mathematical stretch to all three color channels (Red, Green, and Blue) based on the image's overall statistics.
Unlinked Mode (OFF): PixInsight calculates a separate, independent stretch for each channel. This effectively "neutralizes" the background by aligning the histograms of the individual colors. Why Linear Images Need "Unlinking" Initially
Raw astronomical data often has a heavy color bias, frequently appearing green due to the Bayer pattern of color cameras or atmospheric conditions.
Visualizing Hidden Data: Because raw data is "linear," it looks nearly black to the human eye.
Removing the Cast: When you use an Unlinked STF (Ctrl + Click the "Radioactive" icon), PixInsight stretches the channels separately, which removes that heavy green or red cast and lets you see the actual nebula or galaxy detail. The Workflow: When to Toggle the Link
Standard processing in PixInsight follows a specific path regarding the STF link: pixinsight lerar link
Initial Viewing (Unlinked): Upon first opening an image, use an Unlinked STF to see through the color cast and gradients.
Color Calibration: Perform processes like SpectrophotometricColorCalibration (SPCC) or BackgroundNeutralization.
Switch to Linked Mode: Once the image is color-calibrated, you must Link the Channels. A Linked STF will now show the "true" balanced colors you just created. If you keep it unlinked after calibration, the STF will override your calibration and show an artificial color balance. Pro Tips for Managing the Link
Note: It is highly likely that "Lerar Link" is a typo or autocorrect error for the process "LGR Blur" or the tool "Linear Fit" . However, if the user is searching for a specific third-party script or a mispronounced tool, this article addresses the most logical technical fixes within PixInsight. For the purpose of this SEO article, we will assume the user intends to learn about Linear Matching or Reference Linking .
Remove edge artifacts from LN (LN sometimes creates dark borders where correction data was missing).
Cause: Your reference frame has zero-value pixels (bad columns or dead pixels) that your lights don’t have. This breaks the division. In the Screen Transfer Function (STF) , the
Fix: Apply a slight Pedestal (e.g., +100 ADU) to both your reference and lights before LN. In WBPP, under the “Light” tab, set “Pedestal” to 100 for all lights.
Search engines know that "Lerar" is likely a typo. Based on search analytics, users typing "PixInsight lerar link" usually mean one of the following:
| Misspelling | Actual Tool | Success Rate | | :--- | :--- | :--- | | Lerar link | Linear Fit | 95% | | Lerar fit | Linear Fit (Scripts) | 90% | | Lerar linking channels | LRGBCombination | 80% | | Lerar narrowband | NarrowbandNormalization | 70% |
Conclusion: If you want to fix the "Lerar Link," open PixInsight, hit F1 for search, type "Linear Fit" , and follow the steps above.
Searching for “Lerar link problem” on forums yields three specific errors. Here’s how to fix them.
The EZ-LN script automates reference frame creation. It runs an ImageIntegration on selected subs and feeds the result directly into WBPP’s LN reference field. This eliminates manual linking errors. Step 1: DynamicCrop Remove edge artifacts from LN
LN can slightly amplify noise in high-gradient areas. Use MultiscaleLinearTransform (MLT) or NoiseXTerminator on the linear image before stretching.
First, let’s address the keyword. Searching forums like Cloudy Nights or the official PixInsight Forum reveals that “Lerar” is likely a misspelling of:
Alternatively, it could be a phonetic misspelling of “L-E-R-R” – an acronym that doesn’t exist. The most actionable interpretation is “Linear Reference Link.”
In PixInsight, a link refers to telling WBPP which calibration frames (darks, flats, dark-flats) belong to which light frames. Without correct linking, your calibrated lights will have severe dust donuts or amp glow.
The “Lerar Link” workflow is essentially the process of setting up Local Normalization reference files and linking them to your light frames.
Before we dive into Local Normalization, you must understand basic linking. WBPP automates this, but errors happen.