(I tried search on internet, both inside and outside NR, and did not find answer).
I just received shipment of a used Nikon 500mm f/4 G lens. It looks great but I can't figure out how to remove the rear filter holder. Honestly I doubt I will ever use it, but I want to make sure it's not broken in case I need to notify KEH (where I bought it). At first I thought the knob unscrewed, but all this did was remove the knob itself. So I screwed it back on and figured out the knob will push straight down. This seems to loosen the filter holder, but it still won't slide out. What am I doing wrong?