Since Dagors are reputed to sometimes (often? I haven't used many Dagors) shift focus when stopping down from wide open after focusing, requiring refocusing at the taking aperture. I was wondering if their Artar "kin" had the same reputation. Niether of mine have exhibited this tendency(one is a 1909 "APO", the other is a 1950s "Red Dot") and I hadn't heard of anyone commmenting on the problem(if there is one) so I was wonderinabout the experiences of other Artar shooters. Do you have the need to check your focus after stopping down your Artar?