Fotga 1.08x - 1.58x zoom viewfinder eyepiece magnifier for Canon Nikon Pentax Sony Olympus Fujifim Samsung Sigma This zoom viewfinder magnifier is specially designed for DSLR photography Its ratio can reach 1.08x to 1.58x,which can greatly improve the eyesight of photographer who is with glasses or with ages It is improved based on previous series,and come with bigger lens which can better solve the vignette This Viewfinder Magnifier adjusts the viewfinders image by a ratio of 1.08x-1.58x and makes the viewfinders image larger. Magnifying the viewfinder image helps obtain accurate focus with ease. It also greatly enhances focusing accuracy You need not worry about the brightness of the viewfinders image being affected after installation, as this magnifier does not affect the brightness of the viewfinders image at all. This magnifier does not create vignetting affect