diff --git a/libraries/render-utils/src/DeferredBufferRead.slh b/libraries/render-utils/src/DeferredBufferRead.slh
index 3cbed3fcef..f7ab0957cc 100644
--- a/libraries/render-utils/src/DeferredBufferRead.slh
+++ b/libraries/render-utils/src/DeferredBufferRead.slh
@@ -118,7 +118,7 @@ DeferredFragment unpackDeferredFragmentNoPositionNoAmbient(vec2 texcoord) {
 <@include DeferredTransform.slh@>
 <$declareDeferredFrameTransform()$>
 
-vec4 unpackDeferredPosition(DeferredFrameTransform deferredTransform, float depthValue, vec2 texcoord) {
+vec4 unpackDeferredPosition(float depthValue, vec2 texcoord) {
     int side = 0;
     if (isStereo()) {
         if (texcoord.x > 0.5) {
@@ -127,9 +127,14 @@ vec4 unpackDeferredPosition(DeferredFrameTransform deferredTransform, float dept
         }
         texcoord.x *= 2.0;
     }
-    float Zeye = evalZeyeFromZdb(depthValue);
 
-    return vec4(evalEyePositionFromZeye(side, Zeye, texcoord), 1.0);
+    return vec4(evalEyePositionFromZdb(side, depthValue, texcoord), 1.0);
+}
+
+// This method to unpack position is fastesst
+vec4 unpackDeferredPositionFromZdb(vec2 texcoord) {
+    float Zdb = texture(depthMap, texcoord).x;
+	return unpackDeferredPosition(Zdb, texcoord);
 }
 
 vec4 unpackDeferredPositionFromZeye(vec2 texcoord) {
@@ -152,7 +157,7 @@ DeferredFragment unpackDeferredFragment(DeferredFrameTransform deferredTransform
     DeferredFragment frag = unpackDeferredFragmentNoPosition(texcoord);
 
     frag.depthVal = depthValue;
-    frag.position = unpackDeferredPosition(deferredTransform, frag.depthVal, texcoord);
+    frag.position = unpackDeferredPosition(frag.depthVal, texcoord);
 
     return frag;
 }
diff --git a/libraries/render-utils/src/DeferredTransform.slh b/libraries/render-utils/src/DeferredTransform.slh
index 5fccbd6a99..6b0e1cd642 100644
--- a/libraries/render-utils/src/DeferredTransform.slh
+++ b/libraries/render-utils/src/DeferredTransform.slh
@@ -122,17 +122,12 @@ float evalZeyeFromZdb(float depth) {
     return frameTransform._depthInfo.x / (depth * frameTransform._depthInfo.y + frameTransform._depthInfo.z);
 }
 
-vec3 evalEyeNormal(vec3 C) {
-    //return normalize(cross(dFdy(C), dFdx(C)));
-    return normalize(cross(dFdx(C), dFdy(C)));
+float evalZdbFromZeye(float Zeye) {
+    return (frameTransform._depthInfo.x - Zeye * frameTransform._depthInfo.z) / (Zeye * frameTransform._depthInfo.y);
 }
 
-vec3 evalEyePositionFromZeye(int side, float Zeye, vec2 texcoord) {
-    // compute the view space position using the depth
-    // basically manually pick the proj matrix components to do the inverse
-    float Xe = (-Zeye * (texcoord.x * 2.0 - 1.0) - Zeye * frameTransform._projection[side][2][0] - frameTransform._projection[side][3][0]) / frameTransform._projection[side][0][0];
-    float Ye = (-Zeye * (texcoord.y * 2.0 - 1.0) - Zeye * frameTransform._projection[side][2][1] - frameTransform._projection[side][3][1]) / frameTransform._projection[side][1][1];
-    return vec3(Xe, Ye, Zeye);
+vec3 evalEyeNormal(vec3 C) {
+    return normalize(cross(dFdx(C), dFdy(C)));
 }
 
 vec3 evalEyePositionFromZdb(int side, float Zdb, vec2 texcoord) {
@@ -143,6 +138,11 @@ vec3 evalEyePositionFromZdb(int side, float Zdb, vec2 texcoord) {
     return eyePos.xyz / eyePos.w;
 }
 
+vec3 evalEyePositionFromZeye(int side, float Zeye, vec2 texcoord) {
+	float Zdb = evalZdbFromZeye(Zeye);
+    return evalEyePositionFromZdb(side, Zdb, texcoord);
+}
+
 ivec2 getPixelPosTexcoordPosAndSide(in vec2 glFragCoord, out ivec2 pixelPos, out vec2 texcoordPos, out ivec4 stereoSide) {
     ivec2 fragPos = ivec2(glFragCoord.xy);
 
diff --git a/libraries/render-utils/src/lightClusters_drawClusterContent.slf b/libraries/render-utils/src/lightClusters_drawClusterContent.slf
index 739709418d..d4d97c5b16 100644
--- a/libraries/render-utils/src/lightClusters_drawClusterContent.slf
+++ b/libraries/render-utils/src/lightClusters_drawClusterContent.slf
@@ -32,7 +32,7 @@ void main(void) {
     // Grab the fragment data from the uv
     vec2 texCoord = varTexCoord0.st;
 
-    vec4 fragEyePos = unpackDeferredPositionFromZeye(texCoord);
+    vec4 fragEyePos = unpackDeferredPositionFromZdb(texCoord);
     vec4 fragWorldPos = getViewInverse() * fragEyePos;
     
     // From frag world pos find the cluster
diff --git a/libraries/render-utils/src/lightClusters_drawClusterFromDepth.slf b/libraries/render-utils/src/lightClusters_drawClusterFromDepth.slf
index ee2e6e0ccc..c51d45ed44 100644
--- a/libraries/render-utils/src/lightClusters_drawClusterFromDepth.slf
+++ b/libraries/render-utils/src/lightClusters_drawClusterFromDepth.slf
@@ -29,7 +29,7 @@ void main(void) {
     // Grab the fragment data from the uv
     vec2 texCoord = varTexCoord0.st;
 
-    vec4 fragEyePos = unpackDeferredPositionFromZeye(texCoord);
+    vec4 fragEyePos = unpackDeferredPositionFromZdb(texCoord);
     vec4 fragWorldPos = getViewInverse() * fragEyePos;
     
     // From frag world pos find the cluster