Certain embodiments relate to systems and methods for dynamic color shading correction, which can estimate the color shading in a captured image on the fly. The sensing disk is firmly fitted on a driving connecting rod to rotate together for putting out signals to the sensor unit. The rib members include an inner surface and an outer surface. Preferably, the piercing means is achieved by at least one needle. At least one of the transverse struts, over at least part of its cross section, is formed by an extruded profile made of a material that has a higher modulus of elasticity than the material of the longitudinal struts.