Other mistake: Shortly after the house takes off for the first time, in a scene where part of the city can be seen that includes various buildings and houses, the shadow of Carl's house and the balloons can be seen on the ground. At first glance it looks OK, but the angle of the shadows of objects on the ground is completely different from the shadow projected by the house. The buildings on the ground are projecting a shadow to the left, indicating that the sun is low to the right. However Carl's house shadow indicates a light source from behind the camera which is about perpendicular to the shadows on the ground. To be technically correct in this shot, all shadows must point away from the camera and the sun should be located behind the camera if the house's shadow is to be seen in the shot.
Numlock
10th Mar 2011