Hello there, I had my Hasselblad 500 cm for a while and it seems my focus is not always reliable. At times I have it, other times I miss it. I am not sure if it is a matter of me moving the camera or if I am just missing the focus. I just noticed I have a -2 written next to the diopter. Could this affect focus? Also, I am not sure which kind of split-screen I have. Attached photograph. Would you say that changing the diopter and the screen could improve my situation? I know that there are also prisms, but I am really new at this and just always used what it came with my Hasselblad. I know many people suggest ACUTE Matte D, but it would be great starting with identifying my screen! Thank you so much!