I just picked up an InFocus LP425z for movies by my fire pit. I'd like to make a screen as big as I can while still maintaining a somewhat decent picture. I'm not to concerned about high performance as I'll most likely use a painters drop cloth for a screen. I'd like to have the screen 144" wide (for 16:9) but the projection calculator (http://www.projectorcentral.com/InFocus-LP425z-projection-calculator-pro.htm) says I need a higher gain screen and only 3fL. I don't know what the gain is for a drop cloth or what I could use (cheaply) to get a higher gain. I also have no idea what 3fL means but only having 3 can't be a good thing.

So, is it going to work or do I need to plan on reducing my screen size and if so what is the biggest screen I could use?

Thanks

I don't know if I would worry about gain for movie night outside. I assume it will be fairly dark?, so it shouldn't be a big deal.

Going by Projector Centrals calculations, my Projector(Panny 900u) isn't as bright as it should be for my screen size (130"), but it works just fine by me, and I am fussy enough, so I wouldn't worry about "going by the book" as they say for gain.

I recently did movie night outside on 2 separate Saturdays, and wasn't sure of what to expect since all I did for a screen was take a sheet of plywood, and a White Bed sheet, and to my surprise the picture was outstanding, and I was using an older 480p DVD Player besides.

my screen size ended up being 100" diagonal, but the Plywood sheet I had wasn't a full 4x8 piece...The whole experience was a hit with my guest, and the weather was perfect..The second time around I bought some screen tent enclosures(Coleman), cause the damn Mosquitos sucked us dry the first time, and I decided I could just sleep out after the Movies were over, but wouldn't you know a damn Skunk was trying to get in while we were sleeping :p

I have never been so close to a skunk, and I made sure I didn't scare it until he was far enough away not to spray me, but I decided it was time to go back in the House at that point, cause he kept trying to come back towards the Tent.