diff --git a/rtengine/pixelshift.cc b/rtengine/pixelshift.cc
index 68393da38..4a3d9e7e6 100644
--- a/rtengine/pixelshift.cc
+++ b/rtengine/pixelshift.cc
@@ -41,13 +41,17 @@ float greenDiff(float a, float b, bool adaptive, float scale, float stddevFactor
     // calculate the difference between to green samples
     // add a small epsilon to avoid division by zero
     float maxVal = std::max(a, b) + 0.01f;
-    float diff = std::fabs(a - b) / maxVal;
+    float gDiff = std::fabs(a - b);
+    float diff = gDiff / maxVal;
     if(adaptive) {
         float avg = (a+b)/2.f;
         avg *= scale; // revert the colour scaling
-        prnu *= (avg * eperIso);
-        float stddev = sqrtf(avg * eperIso + nreadIso * nreadIso + prnu * prnu);
-        float korr = stddevFactor * stddev / (maxVal * scale);
+        avg *= eperIso;
+        prnu *= avg;
+        float stddev = sqrtf(avg + nreadIso * nreadIso + prnu * prnu);
+//        float korr = stddevFactor * stddev / (a * scale);      // V0: use G1 not scaled by eperIso
+//        float korr = stddevFactor * stddev / (maxVal * scale); // V1: use max(G1,G2) not scaled by eperIso
+        float korr = stddevFactor * stddev / (gDiff / (eperIso * scale)); // V2: use absolute difference abs(G1-G2) scaled by eperISo
         diff -= korr;
     }
     return diff;
@@ -72,12 +76,14 @@ void RawImageSource::pixelshift_simple(int winx, int winy, int winw, int winh, b
     gridSize += ((gridSize & 1) == 0 ? 1 : 0);
     // Lookup table for non adaptive (slider) mode
     LUTf log2Lut(32768, LUT_CLIP_BELOW | LUT_CLIP_ABOVE);
-    log2Lut[0] = 0;
-    const float lutStrength = 2.f;
+    
+    if(detectMotion && !adaptive) {
+        const float lutStrength = 2.f;
+        log2Lut[0] = 0;
+        for(int i=2; i < 65536; i+=2)
+            log2Lut[i>>1] = lutStrength * log2(i) / 100.f;
+    }
     const float scaleGreen = 1.f / scale_mul[1];
-    for(int i=2; i < 65536; i+=2)
-        log2Lut[i>>1] = 2.f * log2(i) / 100.f;
-
     eperIso *= (idata->getISOSpeed() / 100);
     prnu /= 100.f;