I'm getting my tape measure out right now to take some meterings! Are you using a camera or an ambient light meter to get your numbers? If you are using a camera you would want to use a 70% gray card to get good numbers. I am using an ambient light meter witch does not look at the sceen but the actual lumens. About EV, I have been trying to get a difinitive value to compare to the sunny 16 rule witch we know is about 10,000 lumens. take a look at this link on photo.net it shows exactly why I hate to speak in EV. My girlfriend has a degree in photography and she says that no photographers can agree on EV values under different conditions. Take a look and I will post my numbers later!
http://www.photo.net/bboard/q-and-a-...?msg_id=000CCc