One big advantage of rear focus lenses is the ability to smoothly and automatically go into macro focus. This increases the creative options and variety of shooting angles that can be used when filming with the XL1. If this happens, increase the lens to subject distance. One interesting quirk of physics is a phenomenon known as diffraction. In all lenses this can be seen as a blurring of the image.
Diffraction occurs because light can be characteristized as waves.
Although light generally travels in straight lines, it turns in behind an object. This is similar to seeing waves on the water. This causes blurring, even in an aberration-free lens. LOCK button again to return the camcorder to normal operation. Canon developed the Optical Image Stabilization that is currently used in camcorders.