diff --git a/scene.js b/scene.js
index <HASH>..<HASH> 100644
--- a/scene.js
+++ b/scene.js
@@ -580,20 +580,13 @@ function createScene(options) {
     //Compute camera parameters
 
     if(cameraOptions._ortho === true) {
-      var Q = 0.5 * Math.pow(
-        Math.pow(cameraOptions.eye.x - cameraOptions.center.x, 2) +
-        Math.pow(cameraOptions.eye.y - cameraOptions.center.y, 2) +
-        Math.pow(cameraOptions.eye.z - cameraOptions.center.z, 2),
-        0.5
-      )
-
       ortho(projection,
-        Q * -0.5 * width/height,
-        Q * 0.5 * width/height,
-        Q * -0.5,
-        Q * 0.5,
-        Q * scene.zNear,
-        Q * scene.zFar
+        -width/height,
+        width/height,
+        -1,
+        1,
+        scene.zNear,
+        scene.zFar
       )
       cameraParams._ortho = true
     } else {
fix save png scale after zoom