LUT Strength Calculator

Why you should rarely use a LUT at 100%

LUTs are built from a specific source image. When you apply one to footage with different exposure, white balance, or colour profile, it often feels heavy or off. Reducing the strength blends the LUT with the original footage, letting you control how aggressively the look is applied.

In DaVinci Resolve, this is the LUT opacity slider in the Colour page. In Premiere Pro, it's the intensity slider in Lumetri Colour. In Final Cut Pro, it's the Mix slider in the Custom LUT effect. The concept is the same: linear interpolation between your original pixel values and the LUT output.

The maths: what LUT strength actually does

LUT strength is a simple linear blend. For each pixel:
output = original + (lut_output - original) × strength

At 0%, you get the original. At 100%, you get the full LUT output. At 50%, you get an equal blend. This is exactly what Luttie's colour match strength slider does when you use the colour match feature.

Finding the right strength

Start at 100% to see the full intention of the LUT, then pull back until the result feels natural. Watch skin tones specifically — they're the first thing that looks wrong when a LUT is too strong. Most filmic looks land between 60–80%. Creative or stylised LUTs (high contrast, heavy toning) often work better around 40–60%.