I have nikon d5100 and with AF-S DX ZOOM-NIKKOR 18-105mm f/3.5-5.6 G ED VR lens.
pl tell me the exact size of uv filter.
secondly, is it necessary to fix a filter and why?
См. статью: What is the exact mm of uv filter lens for my nikon D5100 with 18-105mm lens?