diff --git a/examples/osghud/osghud.cpp b/examples/osghud/osghud.cpp
index f6683ab1c..c0c548fe6 100644
--- a/examples/osghud/osghud.cpp
+++ b/examples/osghud/osghud.cpp
@@ -208,16 +208,6 @@ int main( int argc, char **argv )
     // create the windows and run the threads.
     viewer.realize();
 
-    // set all the sceneview's up so that their left and right add cull masks are set up.
-    for(osgProducer::OsgCameraGroup::SceneHandlerList::iterator itr=viewer.getSceneHandlerList().begin();
-        itr!=viewer.getSceneHandlerList().end();
-        ++itr)
-    {
-        osgUtil::SceneView* sceneview = itr->get();
-        sceneview->setComputeNearFarMode(osgUtil::CullVisitor::DO_NOT_COMPUTE_NEAR_FAR);
-    }
-
-
     while( !viewer.done() )
     {
         // wait for all cull and draw threads to complete.
diff --git a/src/osgUtil/CullVisitor.cpp b/src/osgUtil/CullVisitor.cpp
index 5f2e5a48a..ca12efa34 100644
--- a/src/osgUtil/CullVisitor.cpp
+++ b/src/osgUtil/CullVisitor.cpp
@@ -177,26 +177,36 @@ void CullVisitor::popProjectionMatrix()
         // so it doesn't cull them out.
         osg::Matrix& projection = *_projectionStack.back();
 
-        double desired_znear = _computed_znear*0.98f;
-        double desired_zfar = _computed_zfar*1.02f;
+        if (projection(0,3)==0.0f && projection(1,3)==0.0f && projection(2,3)==0.0f)
+        {
+            //cout << "Orthographic projection "<<projection<<endl;
+        }
+        else
+        {
 
-        double min_near_plane = _computed_zfar*_nearFarRatio;
-        if (desired_znear<min_near_plane) desired_znear=min_near_plane;
-        
-        // assign the clamped values back to the computed values.
-        _computed_znear = desired_znear;
-        _computed_zfar = desired_zfar;
+            //cout << "Perspective projection "<<projection<<endl;
 
-        double trans_near_plane = (-desired_znear*projection(2,2)+projection(3,2))/(-desired_znear*projection(2,3)+projection(3,3));
-        double trans_far_plane = (-desired_zfar*projection(2,2)+projection(3,2))/(-desired_zfar*projection(2,3)+projection(3,3));
+            double desired_znear = _computed_znear *0.98f;
+            double desired_zfar = _computed_zfar *1.02f;
 
-        double ratio = fabs(2.0f/(trans_near_plane-trans_far_plane));
-        double center = -(trans_near_plane+trans_far_plane)/2.0f;
+            double min_near_plane = _computed_zfar*_nearFarRatio;
+            if (desired_znear<min_near_plane) desired_znear=min_near_plane;
 
-        projection.postMult(osg::Matrix(1.0f,0.0f,0.0f,0.0f,
-                                        0.0f,1.0f,0.0f,0.0f,
-                                        0.0f,0.0f,ratio,0.0f,
-                                        0.0f,0.0f,center*ratio,1.0f));
+            // assign the clamped values back to the computed values.
+            _computed_znear = desired_znear;
+            _computed_zfar = desired_zfar;
+
+            double trans_near_plane = (-desired_znear*projection(2,2)+projection(3,2))/(-desired_znear*projection(2,3)+projection(3,3));
+            double trans_far_plane = (-desired_zfar*projection(2,2)+projection(3,2))/(-desired_zfar*projection(2,3)+projection(3,3));
+
+            double ratio = fabs(2.0f/(trans_near_plane-trans_far_plane));
+            double center = -(trans_near_plane+trans_far_plane)/2.0f;
+
+            projection.postMult(osg::Matrix(1.0f,0.0f,0.0f,0.0f,
+                                            0.0f,1.0f,0.0f,0.0f,
+                                            0.0f,0.0f,ratio,0.0f,
+                                            0.0f,0.0f,center*ratio,1.0f));
+        }
     }
 
     CullStack::popProjectionMatrix();