The Problem: Pattern Noise in Astrophotography

When stacking images for astrophotography, you want to combine dozens or even hundreds of exposures to reduce random noise and bring out faint details in nebulae and galaxies. However, some camera manufacturers require Adobe products to apply automatic distortion correction to their raw files.

This forced distortion correction introduces pattern noise—a subtle, repeating artifact that becomes increasingly visible as you stack more images. While the pattern might be imperceptible in a single frame, it compounds with each additional exposure, eventually creating visible banding and artifacts that ruin your final image.

Why This Happens

Some camera manufacturers (particularly for certain mirrorless lenses) mandate that Adobe applies geometric distortion correction automatically. This is embedded in the raw file metadata and cannot be turned off in Lightroom or Adobe Camera Raw. The correction is baked into every export, TIFF, or DNG you create.

While this distortion correction is beneficial for everyday photography, it creates problems for astrophotography stacking because:

• The correction algorithm introduces interpolation artifacts
• These artifacts create a consistent pattern across all your frames
• Stacking amplifies this pattern instead of averaging it out like random noise
• The result is visible banding or grid patterns in your final stack

The Solution

The Remove Built-In Profile plugin creates a new DNG file from your raw with the mandatory lens profile removed. This allows stacking software like Siril, PixInsight, or DeepSkyStacker to work with clean data that won't introduce pattern noise.

Before and After Comparison

The following comparison shows an individual frame with and without the built-in profile removed:

How to Use

1. Select the raw files you want to process in Lightroom
2. Go to File → Plug-in Extras → Ryan's Raw Tools → Remove Built-In Profile
3. The plugin will create new DNG files without the forced lens profile
4. Use these DNG files in your stacking software
5. Apply lens correction manually in your stacking software if desired

Note: The output DNG files will not have geometric distortion correction applied. If you need distortion correction, apply it in your stacking software after stacking, or re-import the stacked result into Lightroom where you can apply lens corrections to the final image.