>yes it helps,I suppose I could get a magnifer for the d800 >eyepiece which would increase the viewfinder image. thanks >for your help-Tom
I don't think you will need a magnifier, unless you are trying to focus manually. The subject in the DX Box is perfectly clear and easy to see on my D800 with a DX lens attached. It would just be a matter of remembering not to let your desired subject get outside of that DX box when shooting.
I never had a magnifier for my D70, and I never had any trouble framing my shots.