I just acquired a vivitar 3800n Film SLR camera for free (YAY!). Anyways I have never used a non cell phone/digital camera. I have messed with a DSLR before but that was it. This camera is very confusing to me but I have read all the manuals and such that I can find on it. The problem I am having is when I press the shutter button I never get a picture down the view finder. When I took the lens off, it seems that the mirror up top in the camera is not dropping down at all. I have bought new batteries so I know that it is not the cause of my problem. I can see the +,O,- on the right hand side for the aperture but it is always a - meaning it is too dark. If anyone knows anything or can help it would GREATLY appreciated.