hi all about reached my last nerve with my pictures.i have a nikon d90 and celestron 100 f-ed, i can get a super sharp picture using the scope and my d90 with 300mm lens. when i mount the camera to the scope via t-ring just can't get the right focus with live view and the eye piece it looks good until i go to download them. granted my eyes are not what they used to be any insight ?