Nikon 200-400mm and aquatech front cap
I have one on both my 300 f2.8 and 500 f4 and neither lens has a smudge on the front glass. I have had the lens cap on the 500 for over a year now.
Do you leave the protective front glass on either of these lenses ? I suspect the cap will not touch the front element glass at all when the protective glass is removed. Of course for many of us removing the protective glass is not an option.