Assuming we're talking about the ETR line. The nice thing is most of the lenses use a 62mm filter. I haven't had my 40mm that long and I don't remember if it's been used with a filter. It doesn't show in the view finder if it is an issue. The bellows shade can be picked up cheap. With the shade you can use 3"x3" filters. Plus the shade handles I think 40mm to 105mm on it's on. I get the impression a mask of some sort was sold for up to 250mm use.