diff --git a/core/bsdf/microfacet.h b/core/bsdf/microfacet.h
index 9537b19..ac621ed 100644
--- a/core/bsdf/microfacet.h
+++ b/core/bsdf/microfacet.h
@@ -56,7 +56,7 @@ __inline__ __device__ float microfacet_brdf_f(const glm::vec3& wi, const glm::ve
 
     //else
     auto wh = glm::normalize(wi + wo);
-    auto fresnelTerm = schlick_fresnel(1.f, ior, fmaxf(0.f, glm::dot(wh, wi)));
+    auto fresnelTerm = schlick_fresnel(1.f, ior, fmaxf(0.f, glm::dot(wh, wo)));
     auto geometryTerm = geometry_cook_torrance(wi, wo, normal, wh);
 #ifdef DISTRIBUTION_BECKMANN
     auto D = beckmann_distribution(normal, wh, alpha);
diff --git a/gui/canvas.cpp b/gui/canvas.cpp
index bcf3b28..310ab0e 100644
--- a/gui/canvas.cpp
+++ b/gui/canvas.cpp
@@ -7,8 +7,8 @@
 Canvas::Canvas(const QGLFormat &format, QWidget *parent) : QGLWidget(format, parent)
 {
     // lights
-    lights.SetEnvironmentLight("LA_Downtown_Helipad_GoldenHour_Env.hdr");
-    lights.SetEnvironmentLightIntensity(0.f);
+    lights.SetEnvionmentLight(glm::vec3(1.f));
+    lights.SetEnvironmentLightIntensity(0.5f);
     setup_env_lights(lights.environmentLight);
 
     // render params