diff --git a/builtin/settingtypes.txt b/builtin/settingtypes.txt
index fa6591c2f..feb29c2e2 100644
--- a/builtin/settingtypes.txt
+++ b/builtin/settingtypes.txt
@@ -639,25 +639,34 @@ vsync (VSync) bool false
 #    Field of view in degrees.
 fov (Field of view) int 72 45 160
 
-#    Adjust the gamma encoding for the light tables. Higher numbers are brighter.
-#    This setting is for the client only and is ignored by the server.
-display_gamma (Gamma) float 1.0 0.5 10.0
+#    Alters the light curve by applying 'gamma correction' to it.
+#    Higher values make middle and lower light levels brighter.
+#    Value '1.0' leaves the light curve unaltered.
+#    This only has significant effect on daylight and artificial
+#    light, it has very little effect on natural night light.
+display_gamma (Light curve gamma) float 1.0 0.33 3.0
 
 #    Gradient of light curve at minimum light level.
-lighting_alpha (Darkness sharpness) float 0.0 0.0 4.0
+#    Controls the contrast of the lowest light levels.
+lighting_alpha (Light curve low gradient) float 0.0 0.0 3.0
 
 #    Gradient of light curve at maximum light level.
-lighting_beta (Lightness sharpness) float 1.5 0.0 4.0
+#    Controls the contrast of the highest light levels.
+lighting_beta (Light curve high gradient) float 1.5 0.0 3.0
 
-#    Strength of light curve mid-boost.
-lighting_boost (Light curve mid boost) float 0.2 0.0 1.0
+#    Strength of light curve boost.
+#    The 3 'boost' parameters define a range of the light
+#    curve that is boosted in brightness.
+lighting_boost (Light curve boost) float 0.2 0.0 0.4
 
-#    Center of light curve mid-boost.
-lighting_boost_center (Light curve mid boost center) float 0.5 0.0 1.0
+#    Center of light curve boost range.
+#    Where 0.0 is minimum light level, 1.0 is maximum light level.
+lighting_boost_center (Light curve boost center) float 0.5 0.0 1.0
 
-#    Spread of light curve mid-boost.
-#    Standard deviation of the mid-boost Gaussian.
-lighting_boost_spread (Light curve mid boost spread) float 0.2 0.0 1.0
+#    Spread of light curve boost range.
+#    Controls the width of the range to be boosted.
+#    Standard deviation of the light curve boost Gaussian.
+lighting_boost_spread (Light curve boost spread) float 0.2 0.0 0.4
 
 #    Path to texture directory. All textures are first searched from here.
 texture_path (Texture path) path
diff --git a/src/light.cpp b/src/light.cpp
index 9b6f5c210..8196fedff 100644
--- a/src/light.cpp
+++ b/src/light.cpp
@@ -29,44 +29,48 @@ static u8 light_LUT[LIGHT_SUN + 1];
 // The const ref to light_LUT is what is actually used in the code
 const u8 *light_decode_table = light_LUT;
 
+
 struct LightingParams {
-	float a, b, c; // polynomial coefficients
-	float boost, center, sigma; // normal boost parameters
-	float gamma;
+	float a, b, c; // Lighting curve polynomial coefficients
+	float boost, center, sigma; // Lighting curve parametric boost
+	float gamma; // Lighting curve gamma correction
 };
 
 static LightingParams params;
 
+
 float decode_light_f(float x)
 {
-	if (x >= 1.0f) // x is equal to 1.0f half the time
+	if (x >= 1.0f) // x is often 1.0f
 		return 1.0f;
 	x = std::fmax(x, 0.0f);
 	float brightness = ((params.a * x + params.b) * x + params.c) * x;
-	brightness += params.boost * std::exp(-0.5f * sqr((x - params.center) / params.sigma));
-	if (brightness <= 0.0f) // may happen if parameters are insane
+	brightness += params.boost *
+		std::exp(-0.5f * sqr((x - params.center) / params.sigma));
+	if (brightness <= 0.0f) // May happen if parameters are extreme
 		return 0.0f;
 	if (brightness >= 1.0f)
 		return 1.0f;
 	return powf(brightness, 1.0f / params.gamma);
 }
 
+
 // Initialize or update the light value tables using the specified gamma
 void set_light_table(float gamma)
 {
-// Lighting curve derivatives
-	const float alpha = g_settings->getFloat("lighting_alpha");
-	const float beta  = g_settings->getFloat("lighting_beta");
-// Lighting curve coefficients
+// Lighting curve bounding gradients
+	const float alpha = rangelim(g_settings->getFloat("lighting_alpha"), 0.0f, 3.0f);
+	const float beta  = rangelim(g_settings->getFloat("lighting_beta"), 0.0f, 3.0f);
+// Lighting curve polynomial coefficients
 	params.a = alpha + beta - 2.0f;
 	params.b = 3.0f - 2.0f * alpha - beta;
 	params.c = alpha;
-// Mid boost
-	params.boost = g_settings->getFloat("lighting_boost");
-	params.center = g_settings->getFloat("lighting_boost_center");
-	params.sigma = g_settings->getFloat("lighting_boost_spread");
-// Gamma correction
-	params.gamma = rangelim(gamma, 0.5f, 10.0f);
+// Lighting curve parametric boost
+	params.boost = rangelim(g_settings->getFloat("lighting_boost"), 0.0f, 0.4f);
+	params.center = rangelim(g_settings->getFloat("lighting_boost_center"), 0.0f, 1.0f);
+	params.sigma = rangelim(g_settings->getFloat("lighting_boost_spread"), 0.0f, 0.4f);
+// Lighting curve gamma correction
+	params.gamma = rangelim(gamma, 0.33f, 3.0f);
 
 // Boundary values should be fixed
 	light_LUT[0] = 0;