This is the way most 3D films have been shot since the 1960's. They are "CinemaScope" shaped (2.35:1). Great for theaters. This is an actual frame from Dimension 3's first film test c. 1977.
But, television (curently) is 1.33:1, the film has to be cropped, losing a lot of picture on the sides. In some cases this works, but usually interfers with or destroys the 3D effect. Also, there is a degradation of the image quality, as the film frame is not only cropped, but blown up as well - making a grainy, less-focused image (simulated above).
3D movies produced in the 1950's (such as HONDO, HOUSE OF WAX, etc.) were shot 1.33:1, so they have superior image quality (sharper), and much better 3D on broadcast TV.
