I Understand that you cant see the whole field of view?.. Try to find the eye relief sweet spot.. Too close you start to get blackouts and too far you loose FOV.. If You wear glasses, that might be a problem,depending of the fit of the frame or glass thickness. Some eyepieces have very wide eyecups and the Flat Surface is not very ergonòmic, but the BST conical eyecups are quite narrow and offer good eye placement. The eyecup is quite thick though and takes away some usable eye relief. The rubber eyecup is lightly glued to the screw-up hood.. Try to remove the rubber and play a bit with eye position then. Be careful if you use glasses,so not to scratch them.