Fix typo in test

src/camera.rs

@@ -175,10 +175,10 @@ mod tests {
             };
             let expected_x: f64 =
                 ImageSampler::scale(200, 800, target.film_width) - target.film_width * 0.5;
-            assert!((point_on_film_plane.x() - expected_x).abs() < 0.5 / 200.0);
+            assert!((point_on_film_plane.x() - expected_x).abs() < 0.5 / 800.0);
             let expected_y =
                 -ImageSampler::scale(100, 600, target.film_height) + target.film_height * 0.5;
-            assert!((point_on_film_plane.y() - expected_y).abs() < 0.5 / 800.0);
+            assert!((point_on_film_plane.y() - expected_y).abs() < 0.5 / 600.0);
         }
     }
 }