diff --git a/sprout/darkroom/coords/vector.hpp b/sprout/darkroom/coords/vector.hpp
index a6952b19..16edd2dd 100644
--- a/sprout/darkroom/coords/vector.hpp
+++ b/sprout/darkroom/coords/vector.hpp
@@ -99,6 +99,18 @@ namespace sprout {
 					);
 			}
 			//
+			// negate
+			//
+			template<typename Vector>
+			inline SPROUT_CONSTEXPR Vector negate(Vector const& vec) {
+				return sprout::tuples::remake<Vector>(
+					vec,
+					-sprout::darkroom::coords::x(vec),
+					-sprout::darkroom::coords::y(vec),
+					-sprout::darkroom::coords::z(vec)
+					);
+			}
+			//
 			// dot
 			//
 			template<typename Vector>
diff --git a/sprout/darkroom/lights.hpp b/sprout/darkroom/lights.hpp
index aee6dc02..e06b18bb 100644
--- a/sprout/darkroom/lights.hpp
+++ b/sprout/darkroom/lights.hpp
@@ -2,6 +2,9 @@
 #define SPROUT_DARKROOM_LIGHTS_HPP
 
 #include <sprout/config.hpp>
+#include <sprout/darkroom/lights/light_list.hpp>
+#include <sprout/darkroom/lights/parallel_light.hpp>
 #include <sprout/darkroom/lights/point_light.hpp>
+#include <sprout/darkroom/lights/ambient_light.hpp>
 
 #endif	// #ifndef SPROUT_DARKROOM_LIGHTS_HPP
diff --git a/sprout/darkroom/lights/ambient_light.hpp b/sprout/darkroom/lights/ambient_light.hpp
new file mode 100644
index 00000000..df0df8d5
--- /dev/null
+++ b/sprout/darkroom/lights/ambient_light.hpp
@@ -0,0 +1,48 @@
+#ifndef SPROUT_DARKROOM_LIGHTS_AMBIENT_LIGHT_HPP
+#define SPROUT_DARKROOM_LIGHTS_AMBIENT_LIGHT_HPP
+
+#include <limits>
+#include <sprout/config.hpp>
+#include <sprout/tuple/tuple.hpp>
+#include <sprout/tuple/functions.hpp>
+#include <sprout/darkroom/colors/rgb.hpp>
+#include <sprout/darkroom/materials/material.hpp>
+#include <sprout/darkroom/intersects/intersection.hpp>
+
+namespace sprout {
+	namespace darkroom {
+		namespace lights {
+			//
+			// basic_ambient_light
+			//
+			template<typename Color = sprout::darkroom::colors::rgb_f>
+			class basic_ambient_light {
+			public:
+				typedef Color color_type;
+			private:
+				color_type col_;
+			public:
+				explicit SPROUT_CONSTEXPR basic_ambient_light(color_type const& col)
+					: col_(col)
+				{}
+				template<typename Intersection, typename Objects>
+				SPROUT_CONSTEXPR color_type operator()(Intersection const& inter, Objects const&) const {
+					return sprout::darkroom::colors::filter(
+						col_,
+						sprout::darkroom::materials::color(sprout::darkroom::intersects::material(inter))
+						);
+				}
+			};
+			//
+			// make_ambient_light
+			//
+			template<typename Color>
+			inline SPROUT_CONSTEXPR sprout::darkroom::lights::basic_ambient_light<Color>
+			make_ambient_light(Color const& col) {
+				return sprout::darkroom::lights::basic_ambient_light<Color>(col);
+			}
+		}	// namespace lights
+	}	// namespace darkroom
+}	// namespace sprout
+
+#endif	// #ifndef SPROUT_DARKROOM_LIGHTS_AMBIENT_LIGHT_HPP
diff --git a/sprout/darkroom/lights/light_list.hpp b/sprout/darkroom/lights/light_list.hpp
new file mode 100644
index 00000000..126a8a2a
--- /dev/null
+++ b/sprout/darkroom/lights/light_list.hpp
@@ -0,0 +1,65 @@
+#ifndef SPROUT_DARKROOM_LIGHTS_LIGHT_LIST_HPP
+#define SPROUT_DARKROOM_LIGHTS_LIGHT_LIST_HPP
+
+#include <limits>
+#include <sprout/config.hpp>
+#include <sprout/index_tuple.hpp>
+#include <sprout/tuple/tuple.hpp>
+#include <sprout/darkroom/access/access.hpp>
+#include <sprout/darkroom/colors/rgb.hpp>
+
+namespace sprout {
+	namespace darkroom {
+		namespace lights {
+			//
+			// light_list
+			//
+			template<typename... Lights>
+			class light_list {
+			public:
+				typedef sprout::tuples::tuple<Lights...> lights_type;
+				typedef typename sprout::darkroom::access::unit<lights_type>::type::color_type color_type;
+			private:
+				lights_type lights_;
+			private:
+				template<typename Color>
+				SPROUT_CONSTEXPR color_type shade_2(Color const& col) const {
+					return col;
+				}
+				template<typename Color1, typename Color2, typename... Tail>
+				SPROUT_CONSTEXPR color_type shade_2(Color1 const& col1, Color2 const& col2, Tail const&... tail) const {
+					return shade_2(
+						sprout::darkroom::colors::add(col1, col2),
+						tail...
+						);
+				}
+				template<typename Intersection, typename Objects, sprout::index_t... Indexes>
+				SPROUT_CONSTEXPR color_type shade_1(
+					Intersection const& inter, Objects const& objs,
+					sprout::index_tuple<Indexes...>
+					) const
+				{
+					return shade_2(sprout::darkroom::access::get<Indexes>(lights_).template operator()(inter, objs)...);
+				}
+			public:
+				explicit SPROUT_CONSTEXPR light_list(Lights const&... lights)
+					: lights_(lights...)
+				{}
+				template<typename Intersection, typename Objects>
+				SPROUT_CONSTEXPR color_type operator()(Intersection const& inter, Objects const& objs) const {
+					return shade_1(inter, objs, sprout::index_range<0, sizeof...(Lights)>::make());
+				}
+			};
+			//
+			// make_light_list
+			//
+			template<typename... Lights>
+			inline SPROUT_CONSTEXPR sprout::darkroom::lights::light_list<Lights...>
+			make_light_list(Lights const&... lights) {
+				return sprout::darkroom::lights::light_list<Lights...>(lights...);
+			}
+		}	// namespace lights
+	}	// namespace darkroom
+}	// namespace sprout
+
+#endif	// #ifndef SPROUT_DARKROOM_LIGHTS_LIGHT_LIST_HPP
diff --git a/sprout/darkroom/lights/parallel_light.hpp b/sprout/darkroom/lights/parallel_light.hpp
new file mode 100644
index 00000000..810ceae1
--- /dev/null
+++ b/sprout/darkroom/lights/parallel_light.hpp
@@ -0,0 +1,146 @@
+#ifndef SPROUT_DARKROOM_LIGHTS_PARALLEL_LIGHT_HPP
+#define SPROUT_DARKROOM_LIGHTS_PARALLEL_LIGHT_HPP
+
+#include <limits>
+#include <sprout/config.hpp>
+#include <sprout/tuple/tuple.hpp>
+#include <sprout/tuple/functions.hpp>
+#include <sprout/utility/forward.hpp>
+#include <sprout/darkroom/access/access.hpp>
+#include <sprout/darkroom/colors/rgb.hpp>
+#include <sprout/darkroom/coords/vector.hpp>
+#include <sprout/darkroom/rays/ray.hpp>
+#include <sprout/darkroom/materials/material.hpp>
+#include <sprout/darkroom/intersects/intersection.hpp>
+#include <sprout/darkroom/objects/intersect.hpp>
+#include HDR_ALGORITHM_SSCRISK_CEL_OR_SPROUT
+
+namespace sprout {
+	namespace darkroom {
+		namespace lights {
+			//
+			// basic_parallel_light
+			//
+			template<
+				typename Position = sprout::darkroom::coords::vector3d,
+				typename Color = sprout::darkroom::colors::rgb_f
+			>
+			class basic_parallel_light {
+			public:
+				typedef Position position_type;
+				typedef typename sprout::darkroom::access::unit<position_type>::type unit_type;
+				typedef Color color_type;
+			private:
+				position_type dir_;
+				color_type col_;
+			private:
+				template<typename Intersection>
+				SPROUT_CONSTEXPR color_type shade_4(
+					Intersection const& inter,
+					unit_type const& intensity
+					) const
+				{
+					return sprout::darkroom::colors::mul(
+						sprout::darkroom::colors::filter(
+							col_,
+							sprout::darkroom::materials::color(sprout::darkroom::intersects::material(inter))
+							),
+						intensity
+						);
+				}
+				template<typename Intersection, typename LightRayIntersection>
+				SPROUT_CONSTEXPR color_type shade_3(
+					Intersection const& inter,
+					position_type const& diff,
+					position_type const& direction,
+					LightRayIntersection const& light_ray_inter
+					) const
+				{
+					return shade_4(
+						inter,
+						!sprout::darkroom::intersects::does_intersect(light_ray_inter)
+							|| sprout::darkroom::intersects::distance(light_ray_inter)
+								> sprout::darkroom::coords::length(diff)
+							|| sprout::darkroom::intersects::distance(light_ray_inter)
+								< std::numeric_limits<unit_type>::epsilon()
+							? NS_SSCRISK_CEL_OR_SPROUT::max(
+								std::numeric_limits<unit_type>::epsilon(),
+								sprout::darkroom::coords::dot(
+									direction,
+									sprout::darkroom::intersects::normal(inter)
+									)
+								)
+							: 0
+						);
+				}
+				template<typename Intersection, typename Objects>
+				SPROUT_CONSTEXPR color_type shade_2(
+					Intersection const& inter,
+					Objects const& objs,
+					position_type const& diff,
+					position_type const& direction
+					) const
+				{
+					return shade_3(
+						inter,
+						diff,
+						direction,
+						sprout::darkroom::objects::intersect_list(
+							objs,
+							sprout::darkroom::rays::make_ray(
+								sprout::darkroom::coords::add(
+									sprout::darkroom::coords::scale(
+										direction,
+										std::numeric_limits<unit_type>::epsilon() * 256
+										),
+									sprout::darkroom::intersects::point_of_intersection(inter)
+									),
+								direction
+								)
+							)
+						);
+				}
+				template<typename Intersection, typename Objects>
+				SPROUT_CONSTEXPR color_type shade_1(
+					Intersection const& inter,
+					Objects const& objs,
+					position_type const& diff
+					) const
+				{
+					return shade_2(
+						inter,
+						objs,
+						diff,
+						sprout::darkroom::coords::normalize(diff)
+						);
+				}
+			public:
+				SPROUT_CONSTEXPR basic_parallel_light(
+					position_type const& dir,
+					color_type const& col
+					)
+					: dir_(dir)
+					, col_(col)
+				{}
+				template<typename Intersection, typename Objects>
+				SPROUT_CONSTEXPR color_type operator()(Intersection const& inter, Objects const& objs) const {
+					return shade_1(
+						inter,
+						objs,
+						dir_
+						);
+				}
+			};
+			//
+			// make_parallel_light
+			//
+			template<typename Position, typename Color>
+			inline SPROUT_CONSTEXPR sprout::darkroom::lights::basic_parallel_light<Position, Color>
+			make_parallel_light(Position const& pos, Color const& col) {
+				return sprout::darkroom::lights::basic_parallel_light<Position, Color>(pos, col);
+			}
+		}	// namespace lights
+	}	// namespace darkroom
+}	// namespace sprout
+
+#endif	// #ifndef SPROUT_DARKROOM_LIGHTS_PARALLEL_LIGHT_HPP
diff --git a/sprout/darkroom/lights/point_light.hpp b/sprout/darkroom/lights/point_light.hpp
index 655aaa5a..2a06b3d0 100644
--- a/sprout/darkroom/lights/point_light.hpp
+++ b/sprout/darkroom/lights/point_light.hpp
@@ -40,31 +40,12 @@ namespace sprout {
 					unit_type const& intensity
 					) const
 				{
-					return sprout::tuples::remake<color_type>(
-						col_,
-						sprout::darkroom::colors::r(col_)
-							* sprout::darkroom::colors::r(
-								sprout::darkroom::materials::color(
-									sprout::darkroom::intersects::material(inter)
-									)
-								)
-							* intensity
-							,
-						sprout::darkroom::colors::g(col_)
-							* sprout::darkroom::colors::g(
-								sprout::darkroom::materials::color(
-									sprout::darkroom::intersects::material(inter)
-									)
-								)
-							* intensity
-							,
-						sprout::darkroom::colors::b(col_)
-							* sprout::darkroom::colors::b(
-								sprout::darkroom::materials::color(
-									sprout::darkroom::intersects::material(inter)
-									)
-								)
-							* intensity
+					return sprout::darkroom::colors::mul(
+						sprout::darkroom::colors::filter(
+							col_,
+							sprout::darkroom::materials::color(sprout::darkroom::intersects::material(inter))
+							),
+						intensity
 						);
 				}
 				template<typename Intersection, typename LightRayIntersection>
diff --git a/sprout/darkroom/renderers/whitted_style.hpp b/sprout/darkroom/renderers/whitted_style.hpp
index 407843b4..5c0b2836 100644
--- a/sprout/darkroom/renderers/whitted_style.hpp
+++ b/sprout/darkroom/renderers/whitted_style.hpp
@@ -140,10 +140,7 @@ namespace sprout {
 								1 - sprout::darkroom::materials::reflection(sprout::darkroom::intersects::material(inter))
 								),
 							sprout::darkroom::colors::mul(
-								sprout::darkroom::colors::filter(
-									sprout::darkroom::materials::color(sprout::darkroom::intersects::material(inter)),
-									mirror_color
-									),
+								mirror_color,
 								sprout::darkroom::materials::reflection(sprout::darkroom::intersects::material(inter))
 								)
 							)
@@ -169,10 +166,10 @@ namespace sprout {
 					) const
 				{
 					return color_3<Color>(
-					ray,
-					inter,
-					diffuse_color,
-					sprout::darkroom::renderers::whitted_mirror().template operator()<Color>(
+						ray,
+						inter,
+						diffuse_color,
+						sprout::darkroom::renderers::whitted_mirror().template operator()<Color>(
 							camera,
 							objs,
 							lights,