The nikon dk 19 minimises the amount of stray light that enters the viewfinder and enables more comfortable viewing it is particularly helpful for photographers who wear glasses the nikon dk 19 minimises the amount of stray light that enters the viewfinder and enables more comfortable viewing it is particularly helpful for photographers who wear glasses the nikon dk 19 eyecup is compatible with the nikon d2 series d3 series df d4 d700 d800e d800e d810 and f6