[ZLS]

    If this question has been asked already please point me to the thread. 
    What is the proper ratio between screen size and viewing distance? 
    Does it make a difference if it is a Plasma or not? 

                                                                  Thank You

[Will2]

I can't say whether it is correct or not but I'm finding this a useful tool  http://myhometheater.homestead.com/viewingdistancecalculator.html

[ZLS]

I can't say whether it is correct or not but I'm finding this a useful tool  http://myhometheater.homestead.com/viewingdistancecalculator.html

    Thanks, that is just what I am looking for. 
    I did, however, flash back to 9th Grade Geometry!