diff --git a/src/osgVolume/Shaders/volume_accumulateSamples_iso_frag.cpp b/src/osgVolume/Shaders/volume_accumulateSamples_iso_frag.cpp
index 0d1d414c9..75907aee1 100644
--- a/src/osgVolume/Shaders/volume_accumulateSamples_iso_frag.cpp
+++ b/src/osgVolume/Shaders/volume_accumulateSamples_iso_frag.cpp
@@ -29,14 +29,8 @@ char volume_accumulateSamples_iso_frag[] = "#version 110\n"
                                            "            float r = (targetValue-color.a)/(previousColor.a-color.a);\n"
                                            "            texcoord = texcoord - r*dt;\n"
                                            "\n"
-                                           "#if 0\n"
-                                           "            color = texture3D( volumeTexture, texcoord);\n"
-                                           "#else\n"
-                                           "            color.r = 1.0;\n"
-                                           "            color.g = 1.0;\n"
-                                           "            color.b = 1.0;\n"
-                                           "            color.a = 1.0;\n"
-                                           "#endif\n"
+                                           "            color.r = vec4(1.0, 1.0, 1.0, 1.0);\n"
+                                           "\n"
                                            "            float px = texture3D( volumeTexture, texcoord + deltaX).a;\n"
                                            "            float py = texture3D( volumeTexture, texcoord + deltaY).a;\n"
                                            "            float pz = texture3D( volumeTexture, texcoord + deltaZ).a;\n"
@@ -55,6 +49,8 @@ char volume_accumulateSamples_iso_frag[] = "#version 110\n"
                                            "                color.g *= lightScale;\n"
                                            "                color.b *= lightScale;\n"
                                            "            }\n"
+                                           "\n"
+                                           "            color.a = clamp(color.a*TransparencyValue, 0.0, 1.0);\n"
                                            "            return color;\n"
                                            "        }\n"
                                            "\n"
diff --git a/src/osgVolume/Shaders/volume_accumulateSamples_iso_tf_frag.cpp b/src/osgVolume/Shaders/volume_accumulateSamples_iso_tf_frag.cpp
index 2323bb947..db4b51cf2 100644
--- a/src/osgVolume/Shaders/volume_accumulateSamples_iso_tf_frag.cpp
+++ b/src/osgVolume/Shaders/volume_accumulateSamples_iso_tf_frag.cpp
@@ -53,7 +53,7 @@ char volume_accumulateSamples_iso_tf_frag[] = "#version 110\n"
                                               "                color.g *= lightScale;\n"
                                               "                color.b *= lightScale;\n"
                                               "            }\n"
-                                              "            fragColor.a = clamp(fragColor.a*Transparency, 0.0, 1.0);\n"
+                                              "            fragColor.a = clamp(fragColor.a*TransparencyValue, 0.0, 1.0);\n"
                                               "            return color;\n"
                                               "        }\n"
                                               "\n"