Ok i have a sony a-100 these are my lenses sony18- 70/ 3.5-5.6 Minolta af 80-200/1:4.5(22)-5.6 Minolta af 28/1:2.8(22) Minolta af 35-70/1:4(22) Minolta af 50 1:2.8(32) I can't figure out how to get the background out of focus on pics! I've tryed every lens adjusting the app from low to high on every one. and getting as close to the subject as possible. now I did get it on a bottle with my 50 mm app at f/2.8, my iso at 800. But then when I did it on my daughter she was the one out of focus. Any help here?