The only way to have a camera view that LOOKS consistent, is to have a FIXED MOUNT, AND CONSTANT BALL POSITION. Face on is not quite as difficult, but down the line views are nearly impossible to get the same day to day. Slight variations in height ,zoom, angle, and position can make the view look different.
The LOOK of the swing plane view can change drastically with different camera positions. Put the camera on the target line... and the plane will LOOK more shallow. Put the camera more towards the stance line, and the plane will LOOK steeper. The height of the camera will also affect this.
Put the camera ON PLANE. To get it right... the idea of lining up two shafts on A GOLF PLANE ANGLE ( EXACTLY AT THE SAME ANGLE), then looking through the lens and adjusting the camera position until one SEES one shaft is thought by many to be a good way to get this close.
The PLAYER also must be aimed and aligned square to the target line. If, for example, he is aiming a little left and playing a fade, his plane will LOOK steep.
I have heard that Jim McLean puts his cameras ON the target line. I'm not sure what height, but always the same. He is a least looking at the swings the same way every time.
Also... when the PLAYER, changes from shorter to longer clubs, there should be an adjustment, because the relationship of the camera to the hands changed, as well as the plane of the shaft angle. That is, if you want the camera on plane.
HANDS HIGH, BEHIND THE HANDS... IS THOUGHT BY MANY TO BE THE PROPER PLACEMENT.
If one is using a camera to check their plane... it can be tricky. If not done correctly, one may not SEE very close to REALITY, AND MAKE INCORRECT ADJUSTMENTS BASED ON A FALSE, OR MISLEADING READING.