Being new to this fantastic forum I apologize ahead of time if this question is far to simple. I have been a guest here for a while and truly value the collective knowledge that one can gain by keeping my "mouth shut and eyes open". However, being new to the DSLR world I have one question that I was unable to find an answer to after searching.
When I look through the viewfinder of my D20 (I know, I know...it was a gift...my wife must REALLY love me) I see what appears to be a film or filter on it. Almost as if the mirror was coated with something. Is this true of all SLR cameras?
Again, apologies ahead of time for what I am hoping is a simple question. But since this is my first post, I figured I would get a break. 
Thanks 


