Ideal Feet-Lambert for Ambient Light

Discussion in 'Displays' started by Wallis, Feb 18, 2004.

  1. Wallis

    Wallis Agent

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    Hello there. I am installing a home theater system. I'll have an 82" 16:9 screen. The room will have a decent amount of ambient light. The windows will be open during the day, but no light from the windows will shine directly on the screen. The interior lights can be dimmed, but probably will not be off completely during the day. On balance, I'd say that the room will be moderately-lit during the day. (Of course, during the night, ambient light won't be a problem.)

    I'm looking at the Sanyo PLV-70, the Infocus 7200, the BenQ8700, and the Sony HS20. I previously had assumed that I needed to get the PLV-70. Now, I think I might be able to get away with something less bright. The house's previous owners had installed a dropdown Stewart Luxus screen. Unfortunately, I haven't been able to drop it down yet, and thus I don't know what its gain is. Hopefully, I'll figure that out in the next few days and will plug it into my calculations.

    My question is, what is the ideal amount of foot-lamberts for a room that will be moderately lit some of the time and fairly dark other times? My impression is that 30 F-L is a fairly good number. If that's the case, I probably don't need the PLV-70.

    Also, when you all are calculating F-T, do you generally discount the manufacturer's listed lumens by a certain percentage (I know that the listed amounts are usually somewhat inflated)? If so, how much of a discount should I use?
     
  2. ChrisWiggles

    ChrisWiggles Producer

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    "My question is, what is the ideal amount of foot-lamberts for a room that will be moderately lit some of the time and fairly dark other times? My impression is that 30 F-L is a fairly good number. "

    !? 30ft-l is pretty bright. 0 is obviously preferred. You should eliminiate as much light as you possibly can.
     
  3. Wallis

    Wallis Agent

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    Chris, thanks for the response. I may not have been clear in my original post. I am wondering what amount of foot-lamberts I want coming off the screen. I've heard that 30+ is a good idea for ambient light. I've also read a few places that 50+ is a good idea. What are your thoughts?
     
  4. Bill RR

    Bill RR Auditioning

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    I have the Boxlite Cinema HD20, same exact projector as the Sany PLV70. Buy it!!! The price has come down, and in my opinion it is better to have more power than you need. They have a filter for about $70 that will tone it down. I don't use the one I bought. I have a home made screen and it just takes out too much detail.
    There are times when I will have a shade partially open, or lights on half way while eating a burger and fries, and I still get a great image. I am not so sure many other projectors in the price range, or higher can boast the same thing.
    I love this projector in Hi Def as well. Easy to adjust the settings if you want, and no problems with 720p, 1080i or any of that other confussing stuff, projector just scales automatically.

    I sit about 11 feet away and my sceen is 100". It can get bright if the movie switches to a snow scene, but with Avia you probably will tweak it in anyway.

    Hope that helps a little.
     
  5. Gabriel_Lam

    Gabriel_Lam Screenwriter

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    Even 30 ft-lamberts will have a hard time competing with ambient light.

    The screen will probably make a relatively big difference, because some are better at rejecting off-axis light than others. For instance, if they happened to have installed the firehawk fabric, you may be in luck. [​IMG]
     

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