Curve flexibility may dictate the degree of the fulcrum bending correction index, whereby a curve that is less flexible may achieve a greater fulcrum bending correction index.

The optimization design of the CAM curve is very important in the design of a zoom system because it will eventually affect the stability of image surface and flexibility during zoom operation.

Correct mattess should be tactility softness, tall flexibility, curve of physiology of tenability human body and permeability is good.