What size screen for front projector?

I noticed that the new projector from sony used a xenon bulb, while I am by no means a Hometheater guru, that was a new one on me. It also listed no life expectancy of the bulb, which is probably a good thing. If it lasts twice as long as a conventional bulb then it really isn't out of line price wise.

The right answer is what works for HIM with HIS projector. He needs to buy it, set it up on a white wall/sheet/cheap screen, and see what subtended field of vision works for him. Preferences vary and will change when he gets used to thinking of his setup as a small movie screen instead of a large TV.

At 16:9, most home theater people would suggest sitting at 1.5 screen widths which translates into screens

112" wide at 14 feet to 128" wide at 16 feet
128 and 146" diagonal respectively.

3 heights seems a better number With a 2.35:1 constant height setup using an anamorphic lens
131" x 56" at 14 feet to 150 x 64" at 16 feet

Since this is too big for the Sony's light output, he'd do better sitting closer to a smaller screen.

We often sit 11' from a 87x49" (100" diagonal screen. While about right for most DVDs at <= 1.85:1, good scope transfers are too small. This matches the subtended field of view you get in the last row of a commercial theater meeting the THX recomendations.

Looks like the concensus is that he needs a screen around 100"D. and then should adjust his seating accordingly. Thanks for everyone's input.