diff --git a/indra/newview/app_settings/shaders/class1/deferred/blurLightF.glsl b/indra/newview/app_settings/shaders/class1/deferred/blurLightF.glsl
index 3e836e794..c329bcde6 100644
--- a/indra/newview/app_settings/shaders/class1/deferred/blurLightF.glsl
+++ b/indra/newview/app_settings/shaders/class1/deferred/blurLightF.glsl
@@ -97,12 +97,11 @@ void main()
 	vec4 col = defined_weight.xyxx * ccol;
 
 	// relax tolerance according to distance to avoid speckling artifacts, as angles and distances are a lot more abrupt within a small screen area at larger distances
-	float pointplanedist_tolerance_pow2 = pos.z*pos.z*0.00005;
+	float pointplanedist_tolerance_pow2 = pos.z*-0.001;
 
 	// perturb sampling origin slightly in screen-space to hide edge-ghosting artifacts where smoothing radius is quite large
-	float tc_mod = 0.5*(tc.x + tc.y); // mod(tc.x+tc.y,2)
-	tc_mod -= floor(tc_mod);
-	tc_mod *= 2.0;
+	vec2 tc_v = fract(0.5 * tc.xy); // we now have floor(mod(tc,2.0))*0.5
+	float tc_mod = 2.0 * abs(tc_v.x - tc_v.y); // diff of x,y makes checkerboard
 	tc += ( (tc_mod - 0.5) * getKern(1).z * dlt * 0.5 );
 
 	for (int i = 1; i < 4; i++)
diff --git a/indra/newview/app_settings/shaders/class2/deferred/softenLightF.glsl b/indra/newview/app_settings/shaders/class2/deferred/softenLightF.glsl
index 64ac5ebb2..efcb2f189 100644
--- a/indra/newview/app_settings/shaders/class2/deferred/softenLightF.glsl
+++ b/indra/newview/app_settings/shaders/class2/deferred/softenLightF.glsl
@@ -63,7 +63,7 @@ uniform float global_gamma;
 uniform float scene_light_strength;
 uniform mat3 env_mat;
 uniform vec4 shadow_clip;
-uniform mat3 ssao_effect_mat;
+uniform float ssao_effect;
 
 uniform vec3 sun_dir;
 VARYING vec2 vary_fragcoord;
@@ -256,16 +256,6 @@ void calcAtmospherics(vec3 inPositionEye, float ambFactor) {
 	
 	//increase ambient when there are more clouds
 	vec4 tmpAmbient = ambient + (vec4(1.) - ambient) * cloud_shadow * 0.5;
-	
-	/*  decrease value and saturation (that in HSV, not HSL) for occluded areas
-	 * // for HSV color/geometry used here, see http://gimp-savvy.com/BOOK/index.html?node52.html
-	 * // The following line of code performs the equivalent of:
-	 * float ambAlpha = tmpAmbient.a;
-	 * float ambValue = dot(vec3(tmpAmbient), vec3(0.577)); // projection onto <1/rt(3), 1/rt(3), 1/rt(3)>, the neutral white-black axis
-	 * vec3 ambHueSat = vec3(tmpAmbient) - vec3(ambValue);
-	 * tmpAmbient = vec4(RenderSSAOEffect.valueFactor * vec3(ambValue) + RenderSSAOEffect.saturationFactor *(1.0 - ambFactor) * ambHueSat, ambAlpha);
-	 */
-	tmpAmbient = vec4(mix(ssao_effect_mat * tmpAmbient.rgb, tmpAmbient.rgb, ambFactor), tmpAmbient.a);
 
 	//haze color
 	setAdditiveColor(
@@ -273,6 +263,9 @@ void calcAtmospherics(vec3 inPositionEye, float ambFactor) {
 	  + (haze_horizon * haze_weight) * (sunlight*(1.-cloud_shadow) * temp2.x
 		  + tmpAmbient)));
 
+	// decrease ambient value for occluded areas
+	tmpAmbient *= mix(ssao_effect, 1.0, ambFactor);
+	
 	//brightness of surface both sunlight and ambient
 	/*setSunlitColor(pow(vec3(sunlight * .5), vec3(global_gamma)) * global_gamma);
 	setAmblitColor(pow(vec3(tmpAmbient * .25), vec3(global_gamma)) * global_gamma);